Wet-lithographic processing of coordination compounds

Wet-lithographic processing of coordination compounds

Accepted Manuscript Title: Wet-lithographic processing of coordination compounds Authors: Denis Gentili, Massimiliano Cavallini PII: DOI: Reference: ...

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Accepted Manuscript Title: Wet-lithographic processing of coordination compounds Authors: Denis Gentili, Massimiliano Cavallini PII: DOI: Reference:

S0010-8545(12)00293-7 doi:10.1016/j.ccr.2012.12.009 CCR 111663

To appear in:

Coordination Chemistry Reviews

Received date: Revised date: Accepted date:

15-10-2012 11-12-2012 17-12-2012

Please cite this article as: D. Gentili, Wet-lithographic processing of coordination compounds, Coordination Chemistry Reviews (2010), doi:10.1016/j.ccr.2012.12.009 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Edited Dec 16

Wet-lithographic processing of coordination compounds

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Denis Gentili*, Massimiliano Cavallini*

3 4 5 6 7 8 9 10

Consiglio Nazionale delle Ricerche - Istituto per lo Studio dei Materiali Nanostrutturati (CNRISMN), via P. Gobetti 101, 40129 Bologna, Italy. *Corresponding authors. Tel.: +39 051 63988516; fax: +39 051 63988539. E-mail addresses: [email protected] (M. Cavallini); [email protected] (D. Gentili). Contents

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1. Introduction ......................................................................................................................................................... 3

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2. Probe-assisted processing .............................................................................................................................. 4

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2.1.

Dip-pen Lithography................................................................................................................................. 5

14

2.2.

Fluidic-enhanced molecular transfer operation ............................................................................ 6

15

2.3.

Inkjet Printing.............................................................................................................................................. 7

16

2.4.

Local Oxidation Nanolithography........................................................................................................ 7

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3. Stamp-assisted processing ............................................................................................................................. 9 3.1.

Micromolding in capillaries .................................................................................................................10

19

3.2.

Lithographically Controlled Wetting................................................................................................12

20

3.3.

Microtransfer molding ...........................................................................................................................15

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3.4.

Microcontact Printing.............................................................................................................................16

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3.5.

Lithographic Control of Demixing .....................................................................................................17

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4. Combined Top-Down/Bottom-Up approaches.....................................................................................19

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5. Conclusions.........................................................................................................................................................20

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Acknowledgements .................................................................................................................................................21

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References...................................................................................................................................................................22

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Edited Dec 16

ABSTRACT

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Coordination compounds have been applied in many fields of technology, such as electronics,

4

optics and optoelectronics, information storage, sensing and magnetism. These materials are

5

designed to incorporate a variety of functional properties, and at the same time are gifted

6

with functional groups that control their interactions and assembly in the solid state. In order

7

to integrate coordination compounds in solid-state devices, the control of their assembly

8

should not only be at the molecular level but also at different length scales since the precise

9

positioning and size-control of the individual assembled structures are needed. In this

10

direction, wet-lithographic techniques play a key role in the manufacture and application of

11

micro- and nanostructures based on soluble coordination compounds. This review provides

12

an overview of wet-lithographic methods applied to patterning of coordination compounds,

13

highlighting some of the recent advances and the major criticisms. The first part is focused on

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probe-assisted methods while the second part is focused on stamp-assisted ones. Eventually,

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a section on the combination of wet and conventional lithographic methods is presented.

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Keywords: wet-lithography, patterning, coordination compounds, multi-functional

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materials, nanotechnology.

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Abbreviations: DPN, dip-pen nanolithography; FEMTO, Fluidic-enhanced molecular

21

transfer

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benzenetricarboxylate)2; MIMIC, micromolding in capillaries; LCW, lithographically controlled

23

wetting;

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polydimethylsiloxane; SPMs, scanning probe microscopies; SPL, scanning probe lithography;

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AFM, atomic force microscopy; SAMs, self-assembled monolayers; SMMs, single-molecule

26

magnets; SCO, spin-crossover; MOFs, metal-organic frameworks; CPs, coordination polymers;

27

Alq3,

28

octadecyltrimethoxysilane; APTES, 3-aminopropyltriethoxysilane; PC, polycarbonate; PMMA,

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polymethilmethacrylate.

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operation; µTM,

LON,

local

microtransfer

tris-(8-hydroxyquinolinato)

oxidation molding;

AlIII;

nanolithography; µCP,

EBL,

HKUST-1,

microcontact

electron

beam

Cu3(1,3,5-

printing;

lithography;

PDMS,

OTS,

30

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1. Introduction

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The chemistry of coordination compounds is constantly evolving and new compounds are

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daily synthesized. This extraordinary vitality depends on the fact that coordination

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compounds exhibit an enormous variety of chemical and physical properties that find

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application in many fields of technology. Considering the applications in solid-state devices,

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coordination compounds have been applied in: electronics, both as active [1] and passive [2,

8

3] elements, opto-electronics [4, 5], non-linear optics [6], photonics [7], photovoltaics [8],

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spintronics [9], magnetism [10], permanent [11] and erasable [12] memories, and sensing [13,

10

14]. In the last two decades, a lot of these applications were oriented towards nanotechnology

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thus combining the intrinsic properties of the coordination compounds (i.e. related to their

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chemical structure) with the properties arising from their assembly and spatial distribution at

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the micro- and nanoscale. Therefore, technological breakthroughs can be achieved by the

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integration of micro- and nanostructures based on coordination compounds into functional

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devices using fabrication processes that are able to control their dimension and position.

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Architectures with tailored properties [15] can be achieved by bottom-up nanofabrication

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techniques [16] that are powerful tools to directly control the spatial distribution, the lateral

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resolution and in some cases, the molecular packing/orientation of nanostructures based on a

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wide range of functional materials. The interest stems not only from the possibility to design

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new and enhanced properties, but also to combine different properties within the same

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structure, integrating functionalities from libraries of materials which can be processed or

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fabricated on the same technological platform. Since the conventional nanofabrication

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methods, such as photo and electron beam lithography (EBL), cannot be directly used to

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processes coordination compounds, a variety of unconventional wet-lithographic methods

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have been proposed to overcome this limitation.

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Edited Dec 16 This review will provide an overview on the latest work carried out in the wet-lithographic

2

processing of coordination compounds. In particular, it will be shown how soluble

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coordination compounds or their precursors can be lithographically patterned on a variety of

4

technological substrates and eventually integrated into operating devices. The principal

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patterning methods, from the broad family of probe- and stamp-assisted wet-lithography, are

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thoroughly described at the beginning of each section highlighting the most important

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criticisms, then relevant examples in which they have been applied to fabricate micro- and

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nanostructures of coordination compounds are commented. In particular, Section 2 focuses

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on the probe-assisted approaches, while the stamp-assisted ones are addressed in Section 3.

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Finally, Section 4 is dedicated to a short overview of recent results obtained combining

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conventional lithographic methods and bottom-up approaches.

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2. Probe-assisted processing

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Following the invention of scanning probe microscopies (SPMs) [17, 18], which have enabled

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the manipulation of surfaces at the single-atom level [19], scanning probe lithography (SPL)

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techniques have emerged as fabrication tools for patterning surfaces. Nowadays, SPMs and

17

related fabrication techniques are largely diffused in most part of research laboratories. SPLs

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have many important advantages, which includes: (i) the exploitation of a variety of local tip–

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surface interactions, such as mechanical [20, 21], electrical [22] and optical [23]; (ii) the

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possibility to make direct patterning of materials with a resolution down to the nanometer

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scale in standard operating conditions [24] and without the use of masks or prototyping of

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stamps; (iii) usually, SPLs do not require special infrastructures, such as clean rooms,

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vacuum, or aggressive atmospheres.

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On the other hand, major drawbacks of SPLs are due to the printable area, which is limited by

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piezoelectric actuators, and long processing time, which is related to serial nature of these

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Edited Dec 16 techniques (i.e. the nanostructures are fabricated one-by-one). Despite the increase of throughput

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pursued by means of self-actuating/self-sensing cantilever arrays, two-dimensional large parallel

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arrays of probes [21, 25], or inducing collective transformations [21, 26], SPLs are often limited to

4

a tool for proof-of-concept experiments. SPLs were applied both for direct printing of coordination

5

compounds and for the fabrication of patterned substrates on which coordination compounds can be

6

preferentially grown or deposited. This section does not survey the vast field of SPM-based

7

fabrication techniques (deeper detail description is demanded in several specialized reviews [27,

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28]), but provides an overview of the SPLs that have been directly and indirectly used to pattern the

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coordination compounds.

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Dip-Pen Nanolithography (DPN) is a SPL technique introduced by Mirkin in 1999 [29] that

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allows the printing of molecules and functional materials at the micro- and nanometer length

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scale onto specific regions of a surface through a SPM tip. In particular, the tip is inked with

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the printable-material solution (ink) and blown dry, therefore exploiting the capillary effect

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and the formation of a meniscus which spontaneously forms when the SPM tip is engaged at

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surface, the ink is transported on the surface by capillary flow as depicted in Fig. 1a. The size

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of the pattern can be adjusted by changing the scan speed (line-based features) or tip-

19

substrate contact time (dot-based arrays) during the writing procedure [30]. As a

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consequence of its versatility, DPN has been used to generate patterns of a wide range of

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materials, including coordination compounds, on many types of surfaces without the need of

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previous surface functionalization.

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- Figure 1 here -

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Ivanisevic et al. reported the use of redox-active ferrocenylalkylthiol inks (Fc(CH2)11SH and

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Fc(CO)(CH11)SH) patterned on a gold substrate by DPN and selective ink oxidation to trigger

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and guide the assembly of polyanionic oligonucleotide-modified particles in an orthogonal 5 Page 5 of 42

Edited Dec 16 manner [31]. Bellido and co-workers used DPN to fabricate arrays of nanoarchitectures

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ranging from single-crystals of metal-organic frameworks (MOFs) to hollow capsules of

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magnetic polyoxometalates (POMs). MOFs represent an emerging class of crystalline

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inorganic-organic hybrid materials and their controlled deposition is receiving considerable

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attention because they offer a wide range of potential applications, such as gas storage,

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catalysis, separation, and sensing [32, 33]. Femptolitre droplets of MOF and POM precursors

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solutions, which act as reactor vessels confined at the nanoscale, were deposited on gold or

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silicon/silicon oxide surfaces by an AFM tip and exposed to solvent vapors to ensure a

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reduction of the solvent evaporation rate. Controlling the tip-substrate contact time well-

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defined Cu3(1,3,5-benzenetricarboxylate)2 (HKUST-1) nanocrystals ranging from 150 to 650

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nm (Fig 1b-e) and well-defined [ErW10O36]9- hollow capsules ranging from 300 to 500 nm

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were achieved [34].

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2.2. Fluidic-enhanced molecular transfer operation

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Fluidic-enhanced molecular transfer operation (FEMTO) is a pen-type lithography technique

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that uses a surface-patterning tool consisting of a microcantilever device whose edge is

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connected to a well by a micro channel (Fig. 2a). Molecular inks are loaded into the well,

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transferred to the cantilever edge and then printed with a precise control [35]. Compared

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with conventional DPN, FEMTO does not require the reload of the tip, therefore the process

19

works in continuous. On the other hand, the microfluidic circuit requires specifics

20

characteristic of the inks (e.g. viscosity and density) that limit the number of usable solutions.

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- Figure 2 here -

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Carbonell et al. reported the patterning of single-crystal HKUST-1 arrays [36] by FEMTO.

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Femtoliter droplets, containing both inorganic and organic HKUST-1 precursors, were

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deposited onto specific regions of alkanethiol-modified gold surfaces. After reaction of the

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precursors and solvent evaporation, patterns of MOF crystals were fabricated on surfaces (Fig.

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Edited Dec 16 2b). The fine-control of the surface wettability by functionalization with SAMs allows the

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growth of submicrometer single crystals at a desired location on a surface, enabling the

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creation of any desired pattern in a given experiment without the need of prefabricated

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stamps. FE-SEM images of HKUST-1 arrays generated on Au substrates with different

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wettability due to a SAM functionalization are shown in Fig. 2c-e. Interestingly, the size of the

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final crystals can be easily controlled by the volume of the droplet, which in turn is controlled

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by the plasma treatment of the patterning tool.

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Among the printing methods, inkjet printing [37] is a versatile method widely used, in

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laboratory and industrial scale, to print submicrometric and nanostructures on a variety of

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technological substrates. Technologically speaking, inkjet printing is an adaptation of the

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traditional inkjet printer used

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coordination compounds. The availability of versatile inkjet printers, well-known

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technologies to formulate inks, and the robustness of technology used, make inkjet printing

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the most promising technique for industrial applications.

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Success examples of patterning of coordination compounds by inkjet printing were reported

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by Shubert and co-workers using a variety of coordination compounds, including IrIII and RuII

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polypyridyl

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Metallopolymers [39] for application in light-emitting diodes and photovoltaics.

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to print inks containing functional materials, including

complexes

[38]

and,

more

recently,

ZnII

Bis-2,2':6',2''-Terpyridine

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2.4. Local Oxidation Nanolithography

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Local oxidation nanolithography (LON) is a SPL technique that uses a SPM tip as the cathode

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and the water meniscus formed between the tip and surface as the electrolyte to form a

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nanometer-size electrochemical cell where, applying an appropriate bias between the sample 7 Page 7 of 42

Edited Dec 16 and the tip, occurs a localized oxidation of the surface. The meniscus is usually induced by the

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application of an electrical field, although in some cases it can also be driven by the

3

mechanical contact between tip and sample surface. LON was first performed on silicon

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surface and polycrystalline tantalum faces, and then extended to a large number of materials.

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Several excellent reviews are dedicated to LON [22, 40, 41]. As will be discussed below, LON is

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not directly used to pattern coordination compounds on a surface but it is used to form

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nanopatterns where they are deposited or grown. Sugimura and co-workers pioneered the

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use of LON to generated nanostructures consisting of two different types of self-assembled

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monolayers (SAMs) [42]. As shown in Fig. 3a, LON is performed on selected spot of a silicon

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surface functionalized with a SAM of octadecyltrimethoxysilane (OTS) to remove it

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underneath the tip. Thus a second SAM is selectively formed in the oxidized areas by

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immersing the sample in a solution of 3-aminopropyltriethoxysilane (APTES).

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- Figure 3 here -

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Martínez

co-workers

used

this

strategy

for

selective

deposition

of

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[Mn12O12(bet)16(EtOH)4]14+ [43], which is a Mn12-based single-molecule magnet (SMM), and

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ferritin biomolecules [44]. SMMs are a class of molecules exhibiting magnetic properties

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similar to those observed in conventional bulk magnets, and highly controlled thin films and

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patterns are required for their technological applications [45, 46]. The selective deposition of

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Mn12-based SMM exploits its affinity with a SiO2 nanopatterns made by LON respect to a

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APTES SAM, while selective deposition of ferritin, with an accuracy that matches the protein

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size (~10 nm), on either local SiO2 or APTES SAM is driven by the pH of the solution. Fig. 3b-e

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shows the AFM images before and after deposition of the proteins, highlighting the selectivity

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and accuracy with which ferritin molecules can be deposited. In particular, 1D arrays of

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ferritin molecules can be observed by patterning local oxide lines with a lateral dimension of

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about 10 nm (Fig. 3e), showing that a single-molecule deposition can be achieved by matching

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Edited Dec 16 the width of the nanopattern to the molecule size. The same approach was extended to

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anionic nanoparticles based on Prussian-blue analogues [47] by Coronado and co-workers.

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Different from the approaches described above where LON is used to remove a SAM, Sagiv

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and co-workers have pioneered the use of LON to electrochemically modify the terminal

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groups of self-assembled monolayers and selectively functionalize the surface using the so

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named constructive nanolithography [48]. In particular, terminal methyl groups of an OTS

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SAM on silicon are converted in carboxylic acids by applying a proper voltage. Subsequent

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exposure of the patterned OTS surface to a solution of nonadecenyltrichlorosilane (NTS)

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results in the selective self-assembly of a monolayer with terminal ethylenic functions on the

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tip-inscribed sites. A further chemical treatment, which involves the induced photoreaction of

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H2S with the ethylenic groups, produces a thiol-terminated layer that is used to selectively

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attach gold clusters (Au55) and achieve a pattern in the regions previously modified with the

13

LON [49].

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LON is a versatile lithographic method however its major drawbacks are due to the serial

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nature of this method. Noticeably, parallel approaches for the local oxidation, using stamps

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instead of SPM tips, have been reported in several publications [40, 50-53]. The parallel

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approach enlarges the possible applications of LON toward industrial applications.

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3. Stamp-assisted processing

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Soft and unconventional lithographic techniques are a versatile and technologically attractive

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route for micro- and nanomanufacturing [54], and they can be efficiently used to fabricate and

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integrate into operating devices a vast number of coordination compounds nanostructures

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[55]. These techniques are based on the use of a stamp that can be composed of either rigid

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materials, such as metals, ceramics, and rigid polymers, or soft and elastomeric materials,

9 Page 9 of 42

Edited Dec 16 such as polydimethylsiloxane (PDMS). The choice of the material of the stamp may be limited

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by its stability upon exposure to the solvents used in the process.

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Although the lateral resolution of stamp-assisted processes is usually less than that of the

4

corresponding SPL methods, their parallel nature gives the possibility to fabricate in one-step

5

numerous nanostructures over large areas. These characteristics together with their high

6

adaptability to stringent conditions, such as the use of high volatile, aggressive or corrosive

7

solvents, are key advantages for the technological application of the stamp-assisted

8

techniques.

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In this section, we focused our attention on stamp-assisted methods based on: confinement

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and exploitation of the self-organizing properties of the materials in micro (nano) capillaries

11

(e.g. Micromolding in capillaries, Lithographically Controlled Wetting); molding processes (e.g.

12

conventional and modified Microtransfer Molding); formation of self-assembled monolayers

13

(e.g. Microcontact Printing); and exploitation of spatially controlled demixing of

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polymer/coordination compounds blends (e.g. Lithographic Control of Demixing).

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3.1. Micromolding in capillaries

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Micromolding in capillaries (MIMIC) is a simple and versatile soft-lithographic method

18

introduced by Whitesides and coworkers [56]. In MIMIC, an elastomeric stamp, usually made

19

of polydimethylsiloxane (PDMS), is prepared by replica molding of a master fabricated by

20

traditional lithographic methods, such as photolithography or electron beam lithography. In

21

the masters for MIMIC the motif consists of protruding lines that become grooves in the

22

replica. When the stamp is placed in contact with a surface the grooves form the channels. If a

23

solution is poured at the open end of the stamp, the liquid spontaneously fills the channels

24

under the effect of capillary pressure (Fig. 4a). The size of the channels together with the

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Edited Dec 16 concentration of the solution and the self-organization properties of the solute determine the

2

length scale that can be achieved with this process [57].

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- Figure 4 here -

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MIMIC is suitable for fabricating complex microstructures on both planar and curved surfaces

5

and can be used to pattern many soluble materials [58]. In this context, Cavallini et al. showed

6

that a spin-crossover (SCO) compound, cis-bis(thiocyanato)bis(1,10-phenanthroline)FeII, can

7

be patterned in continuous crystalline micro- and nanostripes as well as into logic patterns on

8

silicon surfaces, preserving the spin transition behavior and controlling the crystal

9

orientation of the printed structures [59]. The ability to control the spatial distribution of spin

10

crossover compounds, which are a class of functional materials able to switch their spin state

11

upon external stimuli, is of key importance in many applications, such as molecular memories,

12

sensors, displays and more recently in hybrid electronics and optoelectronics [60]. Greco and

13

co-workers used MIMIC and thermal decomposition to fabricate conductive wires of sub-

14

micrometer width (Fig. 4b,c) by patterning a soluble Pt-carbonyl cluster ([NBu4]2[Pt15(CO)30])

15

[2], while Serban et al. have used the same compounds to fabricate electrodes for working

16

field effect transistors [3].

17

Y. You and co-workers combined the use of MIMIC with de-polymerization and re-

18

polymerization properties of a coordination polymer (CP), achieving the patterning of bi-

19

dimensional micro-arrangements of highly luminescent reticular superstructures on a silicon

20

substrate [61]. CPs are polymers formed by association of metal entities and organic or

21

inorganic ligands, and whose kinetic lability of the metal-ligand bonds in strong coordination

22

solvents may be used for the reproducible construction of highly ordered superstructures

23

useful for a wide range of technological applications (i.e. catalysis, reaction confinement, gas

24

storage

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pyridyl)cyanostilbene in pyridine was allowed to flow into microchannels of a PDMS stamp.

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and

separation)

[62-66].

A

solution

of

Zn

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4,4 ′ -di(4-

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Edited Dec 16 As shown in Fig. 5, inside the capillaries, controlled repolymerization is facilitated through

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selective absorption of the pyridine by the stamp, leading to the formation of microstructures

3

with a pronounced directional order as showed by the strong birefringence under cross-

4

polarized illumination conditions.

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In the same direction, our group reported on patterning of highly conductive coordination

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polymer [Pt2(nBuCS2)4I]n (nBu= n-butyl) demonstrating that it can be an efficient alternative

8

to noble metal microelectrodes for organic electronics in working organic field-effect

9

transistors (OFETs). We used MIMIC and a solution of [Pt2(nBuCS2)4I]n in dichloromethane to

10

exploit its depolymerization and repolymerization properties and fabricate parallel drain (D)

11

and source (S) microelectrodes of pentacene-based OFETs [67].

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3.2. Lithographically Controlled Wetting

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Lithographically Controlled Wetting (LCW) is an unconventional, additive lithographic

15

method particularly attractive for micro- and nanostructuration of soluble functional

16

materials [58, 68-71], whose scheme is shown in Fig. 6a.

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- Figure 6 here -

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In this method a stamp is gently placed in contact with a liquid thin film spread on a substrate,

19

the fluid layer develops instability where the capillary forces pin the solution to the stamp

20

protrusions, forming an array of menisci. As the critical concentration is reached by solvent

21

evaporation, the solute precipitates from the solution onto the substrate inside the menisci,

22

giving rise to a structured thin film that replicates the protrusion of the stamp [72]. The

23

solvent, the interaction among the molecules of solute and the interaction between solute and

24

substrate determine the morphology of the printed features. Wetting/dewetting phenomena,

25

self-assembly and crystallization can be exploited in order to obtain different kinds of

26

patterning [15, 19]. 12 Page 12 of 42

Edited Dec 16 Cavallini and co-workers reported the patterning of Mn12O12(O2CC12H9)16(H2O)4, a Mn12-based

2

single molecule magnet (SMM), with size and distance control on multiple length scales,

3

combining LCW and dewetting phenomena [73]. Different concentrations of Mn12-based SMM

4

solution and stamps with a motif consisting of parallel lines were used to achieve arrays of

5

nanometer-sized aggregates, each made of a few hundred Mn12-based SMM molecules, onto

6

silicon surfaces. The motif of the stamp protrusions imposes the larger length scale, while

7

dewetting phenomena control the spatial correlations on the smaller length scales (size and

8

distance of the molecular aggregates). As a consequence, the pattern exhibits characteristic

9

length scales much smaller than those of the features present in the stamp. Another example

10

of processing of coordination compounds using LCW combined with wetting/dewetting

11

phenomena was proposed by Massi et al. [74], who reported the patterning of tris-(8-

12

hydroxyquinolinato) AlIII (Alq3) onto silicon surfaces with different hydrophilicity. Using

13

copper grids as a stamp and dichloromethane solutions of Alq3 on hydrophilic silicon oxide

14

surfaces continuous patterns of Alq3, whose lateral dimensions depend on the solution

15

concentration, replicating the copper grid bars are obtained. Conversely, on hydrophobic

16

silicon oxide surfaces the film architecture dramatically changes due to dewetting phenomena,

17

arrays of semispherical Alq3 droplets < 10 µm in diameter and 91 ± 5 nm thick are achieved.

18

More recently, our group reported a study of patterning by LCW of a thin deposit of a one-

19

dimensional spin crossover (SCO) compound FeII-(4’-(4’’’-pyridyl)-1,2’:6’1’’-bis-(pyrazolyl)

20

pyridine)2 H(ClO4)3·MeOH that exhibits a reversible, thermally driven, spin transition at room

21

temperature [75]. The patterns consist of parallel sub-micrometric stripes made of randomly

22

oriented nanometric SCO crystals. In that study, we prove that the processing by LCW reduces

23

the crystallites formation time by one order of magnitude preserving the switching properties

24

as the bulk structure. Fig. 6b shows an optical micrograph, with cross polarizers, of a thin

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deposit of FeII-(4’-(4’’’-pyridyl)-1,2’:6’1’’-bis-(pyrazolyl) pyridine)2 H(ClO4)3 ·MeOH

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with

13 Page 13 of 42

Edited Dec 16 micrometric stripes printed by LCW.

Fig. 6c shows an optical micrograph with cross

2

polarizers and the corresponding AFM morphology (inset) of the printed stripes.

3

Ameloot et al. proposed the use of LCW to deposit monodisperse MOF crystals in patterns

4

down to the single-crystallite level as shown in Fig. 7 [76]. HKUST-1 precursors were

5

dissolved in dimethyl sulfoxide, which is a solvent that does not promote HKUST-1 nucleation

6

at room temperature. PDMS stamps were inked with precursors solution, and applied onto a

7

glass surface. Upon being heated at 100 °C, the solvent slowly evaporates giving rise to

8

deposition of MOF crystallites that replicate the stamp motif. The authors observed that the

9

crystallites show a preferred orientation along the [111] axis independently from the nature

10

of the substrate. As rationalized by the authors in Fig. 7a, this result shows that confinement

11

between the stamp and the substrate during in situ crystallization, rather than the substrate

12

functionalization, imposes a preferred orientation on the crystallites.

M

an

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- Figure 7 here -

14

In 2010 Coronado et al. used LCW to fabricate magnetic wires of sub-micrometer width by

15

patterning

16

[MII(H2O)2]3[MIII(ox)3]2(18-crown-6)2 (18-crown-6 = C12H24O6; MIII: Cr, Fe; MII: Mn, Fe, Co, Ni)

17

that, depending on the nature of the trivalent metal ion, exhibit ferro- (Cr3+) or ferrimagnetic

18

(Fe3+) ordering in the 3.6-20 K interval. Furthermore the same materials behave as precursors

19

of magnetic oxides, since upon thermal annealing they can be transformed in room

20

temperature ferromagenetic (MII)3O4 derivatives [77].

21

Eventually LCW was used by our group to orient columnar superstructures formed by

22

stacking of disk-like molecules of a mesogenic phthalocyanine [78], demonstrating its

23

application as time temperature integrator [79], and by Korczagin et al. to fabricate and use as

24

etch resist microstructures of poly (ferrocenylmethylphenylsilane) [80].

polymetallic

oxalate-based

2D

molecular

magnets

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Edited Dec 16 3.3. Microtransfer molding

2

In microtransfer molding (µTM) a drop of solution containing the printable solute is applied

3

to the patterned surface of a polymeric mold and the excess of liquid is removed by doctor

4

blade method. The filled mold is then placed in contact with a substrate and irradiated or

5

heated. After the solvent evaporation, the mold is peeled away carefully to leave a patterned

6

microstructure on the surface of the substrate. µTM is capable of generating both isolated and

7

interconnected microstructures. The most significant advantage of µTM over other micro-

8

lithographic techniques is the ease with which it can fabricate microstructures on non-planar

9

surfaces, a characteristic that is essential for building three-dimensional microstructures

cr

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layer-by-layer. A scheme of µTM is shown in Fig. 8a.

- Figure 8 here -

12

Cavallini et al. showed that patterned thin film of tris(8-hydroxyquinolinato) AlIII (Alq3) onto a

13

silicon surface can be achieved by µTM. For this purpose, the

14

dichloromethane solution of Alq3 and pieces of gold-coated recordable compact disk as

15

stamps. AFM analysis reveals that the process yields a continuous Alq3 film but modulated by

16

the pattern of the stamp [81]. Fig. 8b shows an example of film of Alq3 molded by µTM.

17

µTM was also used to fabricate homogeneous micro- and nanopatterns of SCO nanoparticles

18

of [Fe(NH2trz)](tos)2 (tos = tosylate, NH2trz = 4-amino-1,2,4-triazole) over a large area

19

without compromising their spin crossover properties after the soft lithography step [82].

20

Recently, Bousseksou and co-workers reported a modified µTM process to fabricate ordered

21

arrays of nanodots of [Fe(II)(hptrz)3](OTs)2 (where hptrz = 4-heptyl-1,2,4-triazole and OTs =

22

tosylate) SCO compound doped with acridine orange [83]. They succeed to fabricate a fairly

23

uniform pattern of nanodots with an average lateral size of ! 200 nm and ! 150 nm ticks and a

24

micrometric diffraction grating [84]. Noticeably the luminescence intensity of the

25

chromophor (acridine orange) significantly changes upon the spin transition, even in the

authors have used a

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15 Page 15 of 42

Edited Dec 16 1

isolated nanodots, allowing the direct monitoring of spin crossover phenomenon by

2

fluorescence microscopy, furthermore a significant effect of the molecular spin state change

3

on grating diffraction efficiency is demonstrated (ca. 3% modulation).

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4 3.4. Microcontact Printing

6

Microcontact printing (µCP) is a low cost, and high throughput soft lithographic technique for

7

molecular printing that provides an attractive route to micro- and nanoscale patterns and

8

structures needed for applications in technology [30]. In µCP, an elastomeric stamp, typically

9

fabricated by conventional lithographic methods, is inked with a solution of the molecules

10

(“ink”) to be printed and brought in contact with the surface to form patterned SAMs with

11

submicron lateral dimensions (Fig. 9a). It was first demonstrated for SAMs of alkanethiolates

12

on gold [85] and then extended to a number of other systems [86-88] that are able to form

13

SAMs. µCP routinely forms patterned SAMs containing regions terminated by different

14

chemical functionalities and can be used to create surface with well-defined regions with

15

different physical (e.g. surface energy)[19, 89] and chemical properties on a molecular level.

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Ac ce p

16

cr

5

- Figure 9 here -

17

Mannini et al. reports the preparation of scalable, nanopatterned monolayers of covalently

18

bound SMMs using both direct and indirect µCP [90]. In particular, they used a member of the

19

Mn12 family, [Mn12O12(L)16(H2O)4] with L = 16-(acetylsulfanyl)hexadecanoate, that, after

20

alkaline hydrolysis, can be covalently grafted on gold surfaces via S-Au bonds. In direct µCP, a

21

dilute solution of Mn12 was directly used to ink a PDMS stamp that was subsequently brought

22

in contact with a gold surface to pattern a monolayer of Mn12 with a spatial resolution of

23

several microns. In indirect µCP, the PDMS stamp was inked with an alkanethiol solution and

24

brought in contact with a gold surface, then Mn12 molecules are selectively adsorbed onto the

25

bare gold zones by soaking in an alkaline solution of Mn12. Differently, Fischer and co-worker

26

have used µCP to create domains for the selective nucleation and lateral control of MOF 16 Page 16 of 42

Edited Dec 16 crystals growth on gold substrates [91]. Patterned SAMs of 16-mercaptohexadecanoic acid

2

and 1H,1H,2H,2H-perfluorododecane thiol on Au(111) substrates were fabricated by µCP,

3

immersed into a co-solution of MOF-5 precursors and treated under solvothermal conditions.

4

MOF-5 crystals selectively grow and anchor on carboxylate-terminated areas of the SAM

5

whereas they do not grow on CF3-terminated ones, forming patterned 500 nm thick

6

polycrystalline MOF-5 films. Terfort et al. reported that highly oriented patterned HKUST-1

7

films can also be achieved by deposition of a stable co-solution of MOF precursors on µCP-

8

patterned SAM gold substrates and then exposure to non-solvent vapor, which, as shown in

9

Fig. 9b-c, plays a key role on the final morphology of the film [92]. Instead of use a co-solution

10

of precursors, laterally confined MOF crystals on µCP-patterned SAMs gold substrates can also

11

be grown by sequentially immersing in the solutions of each one of the two MOF precursors

12

(step-by-step approach) as shown in Fig. 10 [93-95].

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1

- Figure 10 here -

14

Recently, Wöll et al. have improved the throughput of this approach using a spray method

15

[96], whereas Gassensmith et al. have extended the grow of both MOF-5 and IRMOF-9 and -10

16

in solvothermal condition to silicon-based surfaces by combining of µCP and copper-catalyzed

17

azide-alkyne cycloaddition [97].

te

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18

d

13

19

3.5. Lithographic Control of Demixing

20

Lithographic control of demixing is a patterning technique introduced by Cavallini and co-

21

workers that combines demixing process and soft-lithography [11, 98]. The demixing process

22

involves the phase-separation of a film made of a mixture two or more components, such as

23

polymer blend or mixture of polymer/solute (molecules, nanoparticles), giving rise to the

24

formation of a double layer consisting of the polymer and the solute [99].

17 Page 17 of 42

Edited Dec 16 This process can be triggered, for instance, by solvent annealing. The thickness of the layers is

2

determined by the volume ratio of the two components in the initial blend and, if the upper

3

thin-film is thermodynamically unstable a dewetting process takes place [19], leading to the

4

fragmentation into smaller aggregates (droplets) in order to achieve the equilibrium

5

conditions. The demixing takes place on a topographically patterned polymer/solute mixture

6

film, which can be fabricated by imprinting [100] or replica molding [11]. When the molded

7

mixture is exposed to solvent vapors, the film swells, and the glass-transition temperature of

8

the polymer decreases below room temperature due to the solvation of polymer chains. Upon

9

these conditions, the structured film surface is smooth due to the effect of the surface tension

10

and a surface contraction occurs at the protrusions in the topographic relief. The surface

11

smoothing occurs at the same time and on the same timescale (<100 s) as the demixing

12

process and the emerged solute is concentrated at the protrusions, transforming the

13

topographic pattern into a chemical pattern. A scheme of lithographically control of demixing

14

is shown in Fig. 11a.

cr

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15

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- Figure 11 here -

Cavallini et al. exploit the lithographic control of demixing of a Mn12–based single molecular

17

magnet (SMM), Mn12O12(O2CC12H9)16(H2O)4, in a polycarbonate (PC) matrix for the fabrication

18

of a logic-pattern containing magnetically readable information [11]. The same authors used

19

the lithographic control of demixing for the fabrication of ordered patterns of nanometric

20

Mn12-based SMM rings on a polycarbonate (PC) matrix [98]. As mentioned above, starting

21

from a patterned film in parallel lines of the binary mixture PC/Mn12, after exposure to vapor

22

solvent demixing process takes place and Mn12-based SMM clusters are forced to emerge and

23

to form small aggregates following the anisotropy of the printed stripes. During the solvent

24

treatment, Mn12-based SMM aggregates grow and coalesce forming larger droplets that, upon

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18 Page 18 of 42

Edited Dec 16 1

a prolonged solvent treatment, reach a critical diameter of about 100 nm and become circular

2

rings (Fig 11b).

3

4. Combined Top-Down/Bottom-Up approaches

5

Although the combination of conventional top-down and bottom-up nanofabrication

6

processes cannot be properly considered as direct wet-lithographic methods, interesting

7

results in coordination compound patterning were obtained. In these cases a mask of resist is

8

fabricated by conventional lithography (e.g. EBL or photolithography) on a surface, then the

9

micrometric structure of coordination compounds is selectively deposited or grown on it.

10

Removing the resist a pattern of structures remains on the surface. Fig. 12a,b shows a general

11

scheme of combined Top-Down/Bottom-Up approaches.

12

Molnar et al. showed the first successful result using SCO [101]. They report on a process for

13

nano- and microscale assembly of the 3D spin-crossover coordination polymer

14

Fe(pyrazine)[Pt(CN)4] using a PMMA mask fabricated by EBL. The process is very efficient

15

because it combines two robust methods, such as EBL and the constructive growth, and

16

allows the fabrication of micro- and nanometric patterns of SCO structures, retaining spin-

17

crossover properties similar to the bulk. The same method was successfully applied to

18

Fe(L)[M(CN)4] (L pyrazine (pz) or azopyridine (azpy) and M Pt, Pd or Ni) compounds

19

[102] (Fig. 12c)

cr

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an

M

d

te

Ac ce p

20

ip t

4

-Figure 12 here -

21

Noticeably, Fe(pyrazine)[Pt(CN)4] forms Hofmann clathrate-like coordination compound on

22

the surfaces, which displays temperature- and light-induced SCO properties. This system is

23

able to accept inclusions of pyridine molecules with a significant influence on the spin

24

transition curves of the films, thus suggesting its application as sensing system.

25 19 Page 19 of 42

Edited Dec 16

5. Conclusions

2

As fabrication of micro- (nano-) structures grows in importance in a wide range of technological

3

fields from microelectronics to sensing through photonics, and information storage technology,

4

there is a mounting necessity for developing a common technological platform able to process

5

materials from solutions on large areas. In this review, we have shown several wet lithographic

6

processes that can be effectively used for the fabrication of small and regularly spaced micro-

7

and nanostructures of soluble coordination compounds, including single-molecular magnets,

8

spin-crossover compounds, metal-organic frameworks, coordination polymers and clusters.

9

The wet methods presented offer immediate advantages in applications where other

10

lithographic methods usually fail and yield nanometer-size structures in a reasonable number

11

of steps without the use of special equipment such as clean-room facilities; hence, they can be

12

proposed as versatile bottom-up methods for laboratory prototyping, with the possibility to

13

be up-scaled to large area fabrication.

14

From a scientific point of view, the next challenge is to develop new methods and new

15

compounds based on a deeper understanding of the intramolecular and molecule–surface

16

interactions, and the possibility to use wet lithography as processes able to locally transform

17

coordination compounds (e.g. perform the chemical reactions directly in the capillary or the

18

application of local electrochemistry (oxidation) directly on a thin film of the coordination

19

compounds). From a technological point of view, the future challenge will be the integration

20

of wet methods with conventional industrial processes for manufacturing, besides the up-

21

scaling of the process itself.

22

We believe that these methods will become increasingly more pervasive in all those fields

23

where the controlled construction of nano-sized architectures of coordination compounds

24

plays a central role.

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Edited Dec 16

Acknowledgements

2

We thank Adrica Kyndiah for her helpful proofreading of the manuscript. MC has received

3

funding under grant ESF-EURYI-DYMOT. DG was supported by the Italian project PRIN prot.

4

2009N9N8RX_003.

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Edited Dec 16

References

3

[1] S.A. VanSlyke, C.H. Chen, C.W. Tang, Appl. Phys. Lett., 69 (1996) 2160-2162.

4 5

[2] P. Greco, M. Cavallini, P. Stoliar, S.D. Quiroga, S. Dutta, S. Zachini, M.C. Lapalucci, V. Morandi, S. Milita, P.G. Merli, F. Biscarini, J. Am. Chem. Soc., 130 (2008) 1177-1182.

6 7

[3] D.A. Serban, P. Greco, S. Melinte, A. Vlad, C.A. Dutu, S. Zacchini, M.C. Iapalucci, F. Biscarini, M. Cavallini, Small, 5 (2009) 1117-1122.

8 9

[4] G.F. de Sa, O.L. Malta, C.D. Donega, A.M. Simas, R.L. Longo, P.A. Santa-Cruz, E.F. da Silva, Coord. Chem. Rev., 196 (2000) 165-195.

cr

ip t

1 2

[5] E. Holder, B.M.W. Langeveld, U.S. Schubert, Adv. Mater., 17 (2005) 1109-1121.

11 12

[6] E. Cariati, M. Pizzotti, D. Roberto, F. Tessore, R. Ugo, Coord. Chem. Rev., 250 (2006) 12101233.

13 14

[7] G.A. Mines, B.C. Tzeng, K.J. Stevenson, J.L. Li, J.T. Hupp, Angew. Chem., Int. Ed., 41 (2002) 154-157.

15

[8] A. Hagfeldt, M. Gratzel, Acc. Chem. Res., 33 (2000) 269-277.

16 17

[9] C. Taliani, V. Dediu, F. Biscarini, M. Cavallini, M. Murgia, G. Ruani, P. Nozar, Phase Transitions, 75 (2002) 1049-1058.

18

[10] R. Sessoli, D. Gatteschi, A. Caneschi, M.A. Novak, Nature, 365 (1993) 141-143.

19 20

[11] M. Cavallini, J. Gomez-Segura, D. Ruiz-Molina, M. Massi, C. Albonetti, C. Rovira, J. Veciana, F. Biscarini, Angew. Chem., Int. Ed., 44 (2005) 888-892.

21 22

[12] K.S. Murray, C.J. Kepert, Spin Crossover in Transition Metal Compounds I, 233 (2004) 195-228.

23

[13] L.G. Beauvais, M.P. Shores, J.R. Long, J. Am. Chem. Soc., 122 (2000) 2763-2772.

24

[14] S.S. Sun, A.J. Lees, Coord. Chem. Rev., 230 (2002) 171-192.

25

[15] M. Cavallini, J. Mater. Chem., 19 (2009) 6085-6092.

26

[16] M. Cavallini, M. Facchini, M. Massi, F. Biscarini, Synth. Met., 146 (2004) 283-286.

27

[17] G. Binnig, H. Rohrer, C. Gerber, E. Weibel, Phys. Rev. Lett., 49 (1982) 57-61.

28

[18] G. Binnig, C.F. Quate, C. Gerber, Phys. Rev. Lett., 56 (1986) 930-933.

29 30

[19] D. Gentili, G. Foschi, F. Valle, M. Cavallini, F. Biscarini, Chem. Soc. Rev., 41 (2012) 44304443.

31 32

[20] T. Sumomogi, T. Endo, K. Kuwahara, R. Kaneko, J. Vac. Sci. Technol., B, 13 (1995) 12571260.

33 34

[21] M. Cavallini, F. Biscarini, S. Leon, F. Zerbetto, G. Bottari, D.A. Leigh, Science, 299 (2003) 531-531.

35

[22] R. Garcia, R.V. Martinez, J. Martinez, Chem. Soc. Rev., 35 (2006) 29-38.

36

[23] P.J. Moyer, K. Walzer, M. Hietschold, Appl. Phys. Lett., 67 (1995) 2129-2131.

37

[24] D.S. Ginger, H. Zhang, C.A. Mirkin, Angew. Chem., Int. Ed., 43 (2004) 30-45.

38 39

[25] P. Vettiger, G. Cross, M. Despont, U. Drechsler, U. Durig, B. Gotsmann, W. Haberle, M.A. Lantz, H.E. Rothuizen, R. Stutz, G.K. Binnig, IEEE Trans. Nanotech., 1 (2002) 39-55. 22

Ac ce p

te

d

M

an

us

10

Page 22 of 42

Edited Dec 16 [26] F. Biscarini, M. Cavallini, R. Kshirsagar, G. Bottari, D.A. Leigh, S. Leon, F. Zerbetto, Proc. Natl. Acad. Sci. U. S. A., 103 (2006) 17650-17654.

3

[27] D. Wouters, U.S. Schubert, Angew. Chem., Int. Ed., 43 (2004) 2480-2495.

4 5

[28] P. Samorì, Scanning Probe Microscopies Beyond Imaging: Manipulation of Molecules and Nanostructures, Wiley-VCH 2006.

6

[29] R.D. Piner, J. Zhu, F. Xu, S.H. Hong, C.A. Mirkin, Science, 283 (1999) 661-663.

7

[30] A.B. Braunschweig, F. Huo, C.a. Mirkin, Nature Chem., 1 (2009) 353-358.

8 9

[31] A. Ivanisevic, J.H. Im, K.B. Lee, S.J. Park, L.M. Demers, K.J. Watson, C.A. Mirkin, J. Am. Chem. Soc., 123 (2001) 12424-12425.

cr

ip t

1 2

[32] A. Betard, R.A. Fischer, Chem. Rev., 112 (2012) 1055-1083.

11

[33] P. Falcaro, D. Buso, A.J. Hill, C.M. Doherty, Adv. Mater., 24 (2012) 3153-3168.

12 13

[34] E. Bellido, S. Cardona-Serra, E. Coronado, D. Ruiz-Molina, Chem. Commun., 47 (2011) 5175-5177.

14

[35] S.G. Vengasandra, M. Lynch, J.T. Xu, E. Henderson, Nanotechnology, 16 (2005) 2052-2055.

15

[36] C. Carbonell, I. Imaz, D. Maspoch, J. Am. Chem. Soc., 133 (2011) 2144-2147.

16

[37] B.J. de Gans, P.C. Duineveld, U.S. Schubert, Adv. Mater., 16 (2004) 203-213.

17 18

[38] V. Marin, E. Holder, R. Hoogenboom, E. Tekin, U.S. Schubert, Dalton Trans., (2006) 16361644.

19 20

[39] C. Friebe, A. Wild, J. Perelaer, U.S. Schubert, Macromol. Rapid Commun., 33 (2012) 503509.

21

[40] F.C. Simeone, C. Albonetti, M. Cavallini, J. Phys. Chem. C, 113 (2009) 18987-18994.

22

[41] D. Wouters, S. Hoeppener, U.S. Schubert, Angew. Chem., Int. Ed., 48 (2009) 1732-1739.

23

[42] H. Sugimura, T. Hanji, K. Hayashi, O. Takai, Adv. Mater., 14 (2002) 524-526.

24 25

[43] R.V. Martinez, F. Garcia, R. Garcia, E. Coronado, A. Forment-Aliaga, F.M. Romero, S. Tatay, Adv. Mater., 19 (2007) 291-295.

26 27

[44] R.V. Martinez, J. Martinez, M. Chiesa, R. Garcia, E. Coronado, E. Pinilla-Cienfuegos, S. Tatay, Adv. Mater., 22 (2010) 588-591.

28 29

[45] M. Cavallini, M. Facchini, C. Albonetti, F. Biscarini, Phys. Chem. Chem. Phys., 10 (2008) 784-793.

30

[46] N. Domingo, E. Bellido, D. Ruiz-Molina, Chem. Soc. Rev., 41 (2012) 258-302.

31 32

[47] E. Coronado, A. Forment-Aliaga, E. Pinilla-Cienfuegos, S. Tatay, L. Catala, J.A. Plaza, Adv. Funct. Mater., 22 (2012) 3625-3633.

33

[48] R. Maoz, E. Frydman, S.R. Cohen, J. Sagiv, Adv. Mater., 12 (2000) 424-+.

34

[49] S.T. Liu, R. Maoz, G. Schmid, J. Sagiv, Nano Lett., 2 (2002) 1055-1060.

35

[50] M. Cavallini, P. Mei, F. Biscarini, R. Garcia, Appl. Phys. Lett., 83 (2003) 5286-5288.

36 37

[51] C. Albonetti, J. Martinez, N.S. Losilla, P. Greco, M. Cavallini, F. Borgatti, M. Montecchi, L. Pasquali, R. Garcia, F. Biscarini, Nanotechnology, 19 (2008) 435303.

38 39

[52] M. Cavallini, Z. Hemmatian, A. Riminucci, M. Prezioso, V. Morandi, M. Murgia, Adv. Mater., 24 (2012) 1197-1201.

Ac ce p

te

d

M

an

us

10

23 Page 23 of 42

Edited Dec 16 [53] M. Cavallini, F.C. Simeone, F. Borgatti, C. Albonetti, V. Morandi, C. Sangregorio, C. Innocenti, F. Pineider, E. Annese, G. Panaccione, L. Pasquali, Nanoscale, 2 (2010) 2069-2072.

3

[54] Y.N. Xia, G.M. Whitesides, Annual Review of Materials Science, 28 (1998) 153-184.

4 5

[55] A.G. Leyva, P. Stoliar, M. Rosenbusch, V. Lorenzo, P. Levy, C. Albonetti, M. Cavallini, F. Biscarini, H.E. Troiani, J. Curiale, R.D. Sanchez, J. Solid State Chem., 177 (2004) 3949-3953.

6

[56] Y.N. Xia, G.M. Whitesides, Angew. Chem.-Int. Edit., 37 (1998) 551-575.

7

[57] P.G. de Gennes, Rev. Mod. Phys., 57 (1985) 827-863.

8

[58] M. Cavallini, C. Albonetti, F. Biscarini, Adv. Mater., 21 (2009) 1043-1053.

ip t

1 2

[59] M. Cavallini, I. Bergenti, S. Milita, G. Ruani, I. Salitros, Z.-R. Qu, R. Chandrasekar, M. Ruben, Angew. Chem., Int. Ed., 47 (2008) 8596-8600.

11

[60] M. Cavallini, Phys. Chem. Chem. Phys., 14 (2012) 11867-11876.

12 13

[61] Y. You, H. Yang, J.W. Chung, J.H. Kim, Y. Jung, S.Y. Park, Angew. Chem., Int. Ed., 49 (2010) 3757-3761.

14

[62] T. Uemura, N. Yanai, S. Kitagawa, Chem. Soc. Rev., 38 (2009) 1228-1236.

15

[63] L. Ma, C. Abney, W. Lin, Chem. Soc. Rev., 38 (2009) 1248-1256.

16

[64] L.J. Murray, M. Dinca, J.R. Long, Chem. Soc. Rev., 38 (2009) 1294-1314.

17 18

[65] J. Lee, O.K. Farha, J. Roberts, K.A. Scheidt, S.T. Nguyen, J.T. Hupp, Chem. Soc. Rev., 38 (2009) 1450-1459.

19

[66] J.-R. Li, R.J. Kuppler, H.-C. Zhou, Chem. Soc. Rev., 38 (2009) 1477-1504.

20 21

[67] D. Gentili, G. Givaja, R. Mas-Balleste, M.-R. Azani, A. Shehu, F. Leonardi, E. Mateo-Marti, P. Greco, F. Zamora, M. Cavallini, Chem. Sci., 3 (2012) 2047-2051.

22

[68] M. Cavallini, F. Biscarini, Nano Lett., 3 (2003) 1269-1271.

23 24

[69] M. Cavallini, P. D'Angelo, V.V. Criado, D. Gentili, A. Shehu, F. Leonardi, S. Milita, F. Liscio, F. Biscarini, Adv. Mater., 23 (2011) 5091-5097.

25 26

[70] D. Gentili, F. Di Maria, F. Liscio, L. Ferlauto, F. Leonardi, L. Maini, M. Gazzano, S. Milita, G. Barbarella, M. Cavallini, J. Mater. Chem., 22 (2012) 20852-20856.

27 28 29

[71] M. Surin, P. Sonar, A.C. Grimsdale, K. Mullen, S. De Feyter, S. Habuchi, S. Sarzi, E. Braeken, A.V. Heyen, M. Van der Auweraer, F.C. De Schryver, M. Cavallini, J.F. Moulin, F. Biscarini, C. Femoni, L. Roberto, P. Leclere, J. Mater. Chem., 17 (2007) 728-735.

30

[72] M. Cavallini, D. Gentili, P. Greco, F. Valle, F. Biscarini, Nat. Protoc., 7 (2012) 1668-1676.

31 32

[73] M. Cavallini, F. Biscarini, J. Gomez-Segura, D. Ruiz, J. Veciana, Nano Lett., 3 (2003) 15271530.

33

[74] M. Massi, M. Cavallini, F. Biscarini, Surf. Sci., 603 (2009) 503-506.

34 35

[75] M. Cavallini, I. Bergenti, S. Milita, J.C. Kengne, D. Gentili, G. Ruani, I. Salitros, V. Meded, M. Ruben, Langmuir, 27 (2011) 4076-4081.

36 37

[76] R. Ameloot, E. Gobechiya, H. Uji-i, J.A. Martens, J. Hofkens, L. Alaerts, B.F. Sels, D.E. De Vos, Adv. Mater., 22 (2010) 2685-2688.

38 39

[77] E. Coronado, C. Marti-Gastaldo, J.R. Galan-Mascaros, M. Cavallini, J. Am. Chem. Soc., 132 (2010) 5456-5468.

Ac ce p

te

d

M

an

us

cr

9 10

24 Page 24 of 42

Edited Dec 16 [78] M. Cavallini, A. Calo, P. Stoliar, J.C. Kengne, S. Martins, F.C. Matacotta, F. Quist, G. Gbabode, N. Dumont, Y.H. Geerts, F. Biscarini, Adv. Mater., 21 (2009) 4688-4691.

3 4

[79] A. Calo, P. Stoliar, F.C. Matacotta, M. Cavallini, F. Biscarini, Langmuir, 26 (2010) 53125315.

5

[80] I. Korczagin, S. Golze, M.A. Hempenius, G.J. Vancso, Chem. Mater., 15 (2003) 3663-3668.

6

[81] M. Cavallini, M. Murgia, F. Biscarini, Nano Lett., 1 (2001) 193-195.

7

[82] C. Thibault, G. Molnar, L. Salmon, A. Bousseksou, C. Vieu, Langmuir, 26 (2010) 1557-1560.

8 9

[83] C.M. Quintero, I.y.A. Gural'skiy, L. Salmon, G. Molnar, C. Bergaud, A. Bousseksou, J. Mater. Chem., 22 (2012) 3745-3751.

10 11

[84] A. Akou, I.A. Gural'skiy, L. Salmon, C. Bartual-Murgui, C. Thibault, C. Vieu, G. Molnar, A. Bousseksou, J. Mater. Chem., 22 (2012) 3752-3757.

12

[85] A. Kumar, G.M. Whitesides, Appl. Phys. Lett., 63 (1993) 2002-2004.

13

[86] M. Cavallini, M. Bracali, G. Aloisi, R. Guidelli, Langmuir, 15 (1999) 3003-3006.

14

[87] M. Cavallini, G. Aloisi, M. Bracali, R. Guidelli, J. Electroanal. Chem., 444 (1998) 75-81.

15 16

[88] M. Cavallini, R. Lazzaroni, R. Zamboni, F. Biscarini, D. Timpel, F. Zerbetto, G.J. Clarkson, D.A. Leigh, J. Phys. Chem. B, 105 (2001) 10826-10830.

17

[89] A. Kumar, G.M. Whitesides, Science, 263 (1994) 60-62.

18 19

[90] M. Mannini, D. Bonacchi, L. Zobbi, F.M. Piras, E.A. Speets, A. Caneschi, A. Cornia, A. Magnani, B.J. Ravoo, D.N. Reinhoudt, R. Sessoli, D. Gatteschi, Nano Lett., 5 (2005) 1435-1438.

20 21

[91] S. Hermes, F. Schroder, R. Chelmowski, C. Woll, R.A. Fischer, J. Am. Chem. Soc., 127 (2005) 13744-13745.

22

[92] J.-L. Zhuang, D. Ceglarek, S. Pethuraj, A. Terfort, Adv. Funct. Mater., 21 (2011) 1442-1447.

23 24

[93] O. Shekhah, H. Wang, S. Kowarik, F. Schreiber, M. Paulus, M. Tolan, C. Sternemann, F. Evers, D. Zacher, R.A. Fischer, C. Woll, J. Am. Chem. Soc., 129 (2007) 15118-15119.

25 26

[94] C. Munuera, O. Shekhah, H. Wang, C. Woell, C. Ocal, Phys. Chem. Chem. Phys., 10 (2008) 7257-7261.

27

[95] J. Zhuang, J. Friedel, A. Terfort, Beilstein Journal of Nanotechnology, 3 (2012) 570-578.

28 29

[96] H.K. Arslan, O. Shekhah, J. Wohlgemuth, M. Franzreb, R.A. Fischer, C. Woell, Adv. Funct. Mater., 21 (2011) 4228-4231.

30 31

[97] J.J. Gassensmith, P.M. Erne, W.F. Paxton, C. Valente, J.F. Stoddart, Langmuir, 27 (2011) 1341-1345.

32 33

[98] M. Cavallini, J. Gomez-Segura, C. Albonetti, D. Ruiz-Molina, J. Veciana, F. Biscarini, J. Phys. Chem. B, 110 (2006) 11607-11610.

34

[99] F. Bruder, R. Brenn, Phys. Rev. Lett., 69 (1992) 624-627.

35 36 37

[100] C.C. Cedeno, J. Seekamp, A.P. Kam, T. Hoffmann, S. Zankovych, C.M.S. Torres, C. Menozzi, M. Cavallini, M. Murgia, G. Ruani, F. Biscarini, M. Behl, R. Zentel, J. Ahopelto, Microelectron. Eng., 61-2 (2002) 25-31.

38 39

[101] G. Molnar, S. Cobo, J.A. Real, F. Carcenac, E. Daran, C. Vien, A. Bousseksou, Adv. Mater., 19 (2007) 2163-2167.

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[102] C. Bartual-Murgui, L. Salmon, A. Akou, C. Thibault, G. Molnar, T. Mahfoud, Z. Sekkat, J.A. Real, A. Bousseksou, New J. Chem., 35 (2011) 2089-2094.

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Figures legends

3 Fig. 1. (a) Schematic representation of DPN. A water meniscus forms between the AFM tip

5

coated with alkanethiols and the Au substrate. The size of the meniscus, which is controlled

6

by relative humidity, affects the molecule transport rate, the effective tip-substrate contact

7

area, and DPN resolution. From ref. [29]. Reprinted with permission from AAAS. (b-e) FE-SEM

8

images of the HKUST-1 nanocrystals grown inside the confined solution droplets deposited by

9

DPN on a CH3-terminated SAM. (b) Nanoarray; scale bar 2 μm. (c) Details of the nanocrystals

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grown inside each dot-like feature; scale bar 1 μm. Growth of a single crystal per dot

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nanoarray viewed from above (d) and at a 45° tilt angle (e); scale bars 2 μm and 200 nm

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respectively. Adapted from ref. [34] with permission of The Royal Society of Chemistry.

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Fig. 2. (a) Schematic diagram of the FEMTO surface-patterning tool. Adapted with permission

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from ref. [35]. (b) Schematic illustration of the fabrication of single-crystal MOF arrays by

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using direct-write FEMTO. (c-e) FESEM images of the HKUST-1 arrays fabricated on (c) NH2-,

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(d) CH3-, and (e) CF3-terminated SAMs on gold substrates. Scale bars represent 10 µm, and

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(insets) 2 µm. Adapted with permission from ref. [36]. Copyright 2011 American Chemical

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Society.

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Fig. 3. Patterning of ferritin molecules by combining local oxidation nanolithography and

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surface functionalization at pH values close to neutral. (a) Scheme of the major steps of the

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nanopatterning process. (b) Local oxide pattern before ferritin deposition. (c) AFM image of

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the distribution of the proteins on the nanopattern. (d) Parallel array of narrow local oxide

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lines. The inset shows the AFM phase image of the marked section of a line. (e) Topography

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AFM image of the five ferritin molecules lines deposited on the 10 nm local oxide lines. The

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inset shows the AFM phase image of a section of a line containing individual ferritin molecules.

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The ferritin molecules appear as dark spots. (scale bars: 1 µm (b,c), 100 nm (d,e)). Reprinted

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with permission from ref. [44]. Copyright Wiley-VCH Verlag GmbH and Co. KGaA.

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Fig. 4. (a) Schematic representation of micromolding in capillaries (MIMIC). (b,c) TEM images

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of Pt microstripes fabricated on Silicon by decomposition of ([NBu4]2[Pt15(CO)30] precursor

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(b) a conventional secondary electron image; (c) image obtained with a backscattered 27 Page 27 of 42

Edited Dec 16 1

electrons detector, sensitive mainly to the sample composition. Adapted with permission

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from ref. [2]. Copyright 2008 American Chemical Society.

3 Fig. 5. Structure of the coordination polymer and conceptual representation of the

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coordinative patterning by soft-lithography-driven coordination polymerization. Reprinted

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with permission from ref. [61]. Copyright Wiley-VCH Verlag GmbH and Co. KGaA.

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Fig. 6. (a) Scheme of Lithographically Controlled Wetting (LCW). (b) Optical micrograph

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recorded with cross polarizers of a thin deposit of FeII-(4’-(4’’’-pyridyl)-1,2’:6’1’’-bis-

cr

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(pyrazolyl) pyridine)2 H(ClO4)3·MeOH prepared by drop casting. (c) Optical micrograph

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recorded with cross polarizers of micrometric stripes of the same compound printed by LCW.

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The inset shows the corresponding AFM morphology (z scale 0-70 nm). Adapted with

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permission from ref. [75]. Copyright 2011 American Chemical Society.

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Fig. 7. (a) Schematic representation of nucleation, growth, and orientation of HKUST-1

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crystals in confinement during solvent evaporation. (b-c) Patterned deposition of HKUST-1

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crystals: (b) positive replica (scale bar 25µm); (c) details of individual crystals (scale bar

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1µm) viewed from above (left) and at a 35° angle (right) Adapted with the permission from

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ref. [76]. Copyright Wiley-VCH Verlag GmbH and Co. KGaA.

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Fig. 8. (a) Schematic illustration of the procedure for modified micro-transfer molding. A drop

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of liquid “ink” is applied to the patterned surface of mold, after that the mold is placed in

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contact with a substrate. After liquid has evaporated the mold is peeled away, leaving a

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continuous patterned film. (b) AFM image printed Alq3 thin film. Adapted with the permission

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from ref. [81]. Copyright 2001 American Chemical Society.

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Fig. 9. (a) Schematic representation of microcontact printing (µCP). (b-c) AFM images of

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patterned HKUST-1 on 11-mercaptoundecanoic acid patterned surfaces: (b) After ten cycles

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with ethanol vapor treatment. (c) After one cycle using methanol vapor. Note that the PDMS

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stamps used for µCP!have the same size in (b) and (c). Adapted with permission from ref. [92].

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Copyright Wiley-VCH Verlag GmbH and Co. KGaA.

32 33 28 Page 28 of 42

Edited Dec 16 Fig. 10. (a) Schematic diagram for the step-by-step growth of the MOFs on the SAM, by

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repeated immersion cycles, first in solution of metal precursor and subsequently in a solution

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of organic ligand. (b) Scanning electron micrographs of Cu3BTC2·xH2O MOF (40 cycles) grown

4

on a SAM laterally patterned by microcontact printing (µCP) consisting of COOH-terminated

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squares and CH3-terminated stripes. Reprinted with the permission from ref. [93]. Copyright

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2007, American Chemical Society.

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Fig. 11. (a) Schematic illustration of the procedure for Lithographically Control of Demixing.

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The scheme shows the smoothing and Mn12 aggregation processes occurring during the

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solvent vapors treatment and its transformation in nanoring. (b) AFM image of the early stage

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of ring formation. Adapted with the permission from ref. [98]. Copyright 2006, American

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Chemical Society.

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Fig. 12. Schematic representation of combined Top-Down/Bottom-Up approaches. (a) Mask

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fabrication by photolithography. (b) Coordination compounds deposition/growth followed by

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the mask removal (e.g. by chemical etching). (c) Low-energy SEM image of a 2 mm pattern (ca.

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150 nm thick) of Fe(pyrazine)[Pt(CN)4], showing the surface details. Adapted with the

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permission from ref. [101]. Copyright Wiley-VCH Verlag GmbH and Co. KGaA.

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Highlights

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Highlights of this review are: Direct Micro and nanopatterning of soluble compounds,



Demonstration of several coordination compounds based working devices



The use of wet lithography for technological applications

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