Understanding Pattern Formation in 2D Metal–Organic Coordination Systems on Solid Surfaces

Abstract

Creation of two-dimensional superstructures using coordination chemistry principles is a promising method to fabricate new nanomaterials with predefined architecture and functionality. In this work we use a simple lattice Monte Carlo (MC) model to study the mixed self-assembly of a family of ditopic linkers and metal atoms adsorbed on a triangular lattice. In particular, we focus on the role of directional short-range metal–linker interactions in the formation of local coordination motifs responsible for the development of periodic and random molecular patterns. To that end canonical ensemble MC simulations were performed in which both components of the adsorbed mixture were assumed to consist of discrete segments, each of which occupies one lattice site. Accordingly, the metal atoms were modeled as single segments while the linker was represented by a rigid linear chain whose terminal segments are able to form directional bonds with a neighboring metal atom. The simulated results demonstrated that depending on the assumed directionality of the metal–linker interaction and composition of the adsorbed phase, the self-assembly can lead to the formation of largely diversified planar structures including random strings, nanorings, chiral and achiral porous networks, and fractal-like aggregates. The insights from our theoretical investigations can be helpful in designing 2D metal–organic molecular architectures comprising simple functional building blocks.