Theoretical Modeling of the Metal‐Organic Precursors of Anthracene‐Based Covalent Networks on Surfaces

Abstract

Surface‐assisted fabrication of molecular network architectures has been a promising route to low‐dimensional materials with unique physicochemical properties and functionalities. One versatile way in this field is the Ullmann coupling reaction of halogenated organic monomers on catalytically active metallic surfaces. In this work, using the coarse‐grained Monte Carlo simulations, we studied the on‐surface self‐assembly of metal‐organic precursors preceding the covalent Ullman‐type linkage of tetrahalogenated anthracene building blocks. To that end, a series of positional isomers was examined and classified with respect to their ability of creation of extended network structures. Our simulations focused on the identification of basic types of self‐assembly scenarios distinguishing enantiopure and racemic systems and producing periodic and aperiodic networks. The calculations carried out for selected tectons demonstrated wide possibilities of controlling porosity (e. g. pore size, shape, periodicity, chirality, heterogeneity) of the networks by suitable functionalization of the monomeric unit. The findings reported herein can be helpful in rational designing of 2D polymeric networks with predefined structures and properties.

On-surface Ullmann coupling of halo-derivatives of arenes: Monte Carlo simulations for tetracene

“…Specifically, when T drops below 0.2, the fraction of R-S tends to zero, which is markedly different from all of the corresponding results of this study. On the other hand, this behaviour was observed in our previous works [47][48][49][50][51] on the smaller PAH derivatives.…”

“…Among diverse computational chemistry tools, the coarse-grained MC simulations turned out to be an effective way of predicting the architecture of metal-organic intermediates, as confirmed by the corresponding experimental data -obtained, for example, with STM imaging of adsorbed overlayers [11][12][13][14]. Those results proved that the simplified coarse-grained modelling of aromatic adparticles (naphthalene, anthracene and phenanthrene) [47][48][49][50][51] and metal adatoms on solid substrates is a suitable and sufficiently accurate representation of the real systems enabling correct reproduction of complex 2D molecular patterns. Accordingly, in this contribution, we continue our research on the Ullmann coupling of halogenated PAHs and focus on the isomers of the longer linear aromatic hydrocarbon comprising four fused benzene rings, tetracene (t) [47][48][49][50][51].…”

“…Those results proved that the simplified coarse-grained modelling of aromatic adparticles (naphthalene, anthracene and phenanthrene) [47][48][49][50][51] and metal adatoms on solid substrates is a suitable and sufficiently accurate representation of the real systems enabling correct reproduction of complex 2D molecular patterns. Accordingly, in this contribution, we continue our research on the Ullmann coupling of halogenated PAHs and focus on the isomers of the longer linear aromatic hydrocarbon comprising four fused benzene rings, tetracene (t) [47][48][49][50][51]. As was observed in the previous studies, the main structural features of the obtained metal-organic assemblies were highly dependent on the number and position of halogen substituents in the PAH building blocks.…”

“…The MC model adopted in the present study was based on our earlier research on the substituted PAHs, in which the coarse-graining method was used for the smaller PAH units [47][48][49][50][51]. The tetracene molecules were treated as rigid linear rods consisting of four connected segments representing aromatic rings.…”

Off-Lattice Coarse-Grained Model of Surface-Confined Metal–Organic Architectures

“…SMONs consisting of bi-, tri-, and tetrafunctional organic ligands and metal atoms had been studied. It is established how the geometry of adsorbed molecules (symmetry, size, and arrangement of the functional groups) affects the characteristics of the self-assembling SMONs. ,,,,,− The preferred coordination number of the metal center is also shown to play a significant role in the self-assembly of SMONs. ,,, In these studies, the main parameters affecting the morphology of synthesized SMONs are determined. These include the surface coverage, pressure and metal/ligand ratio, ,,,,− ,, the preferred coordination number of the metal center, ,,,, and temperature. ,,,,,,,, …”