Surface-Confined Metal-Organic Precursors Comprising Naphthalene-Like Derivatives with Differently Distributed Halogen Substituents: A Monte Carlo Model

摘要

The on-surface synthesis of organic polymers has been recently recognized as a useful method to create low-dimensional covalently bonded structures with tailorable topology and functions. In this work, the Monte Carlo simulation method was used to study the metal-organic precursors of covalent polymers formed in the Ullmann-type coupling reaction of halogenated naphthalene derivatives. To this purpose, a coarse-grained model was proposed in which the monomers, represented by a pair of interconnected segments, and two-coordinate metal atoms (one segment) were adsorbed on a triangular lattice-mimicking (111) catalytically active crystalline surface. Different distributions of halogen atoms in the naphthalene molecules were modeled using the directional interactions assigned to these units, sustaining the resulting metal-tecton reversible links. Depending on the halogen content and distribution, the simulations predicted the creation of diverse supramolecular connections such as linear and cyclic aggregates and other more complex forms. Moreover, in the case of prochiral monomers, the calculations demonstrated basic structural differences between the enantiopure and racemic assemblies in which chiral separation or mixing was observed. The obtained results can be helpful in directing the surface-assisted polymerization reactions toward organic structures with predefined size, shape, symmetry, and connectivity.