Supramolecular assembly of a 2D binary network of pentacene and phthalocyanine on Cu(100)

A crystalline nanoporous molecular network was tailored by supramolecular assembly of pentacene and F16CuPc on Cu(100). The structure and self-assembly mechanisms of the pure and binary layers were analyzed by STM. F16CuPc films and mixed layers of pentacene/F16CuPc in a ratio of 2:1 show two enantiomorphic chiral domains with high structural order in contrast to pentacene which exhibits no long-range order in pure films. A model of the epitaxial relationship on Cu(100) is given, which suggests C-F...H bonding as a possible driving force for the bimolecular self-assembly in addition to the still strong interaction between the substrate and the organic bilayer.

Supramolecular chemistry at interfaces: molecular recognition on nanopatterned porous surfaces

Through the illustration of key examples that have recently appeared in the literature, the intention of this review is to provide a perspective of current advances on the molecular recognition at the interfaces aimed at the engineering of multifunctional organic-based materials. The great interest in such systems has been motivated by the need to fabricate smaller and smaller components in order to improve, for example, the information storage capabilities of classical silicon-based devices. Although great progress has been achieved on the exploitation of "top-down" approaches, strong hope is now put on the development of hybrid devices in which the elementary components are replaced with single organic molecules. Nevertheless, the drive towards such devices is restricted by both their stability and difficulties to precisely control and manipulate the structural organisation at the molecular level. To overcome these restrictions, the use of nanotemplated surfaces featuring porous domains in which responsive functional molecules can be precisely accommodated at the single-molecule level is one of the most promising approaches. In the first part of this manuscript, we therefore illustrate the main engineering strategies [1) through non-covalent interactions, 2) surface-confined covalent reactions and 3) assembly of pre-organised cavities such as synthetic macrocycles] currently in use to create two-dimensional (2D) patterned surfaces displaying porous structures at the nanoscale level. Such networks, featuring periodic hollow domains (controllable both in shape and size), are of particular significance as their cavities can be used as receptors for the recognition of remotely controllable functional molecules. In the second part, the confinement of molecular guests within the cavities is discussed, emphasising the selectivity and dynamics of key assemblies, with a particular focus on the biomolecular recognition and post-assembly covalent functionalisation, which could provide the opportunity to fabricate devices currently beyond our reach on an unprecedented precision and efficiency. All the examples will be discussed in terms of structural organisation as studied by scanning tunnelling microscopy (STM) techniques.