Modeling of the 2D self-assembly of tripod-shaped functional molecules with patchy interaction centers

Abstract

Surface-confined self-assembly of star-shaped functional molecules has been recently recognized as a promising method to fabricate extended superstructures with predefined architectures and physico-chemical functions. In this work we use the Monte Carlo (MC) method to explore 2D self-assembly of rigid tripod-shaped tectons equipped with patchy interaction centers located at the ends of molecular arms. These angular interaction zones represent terminal functional groups, which due to some flexibility/extended size, can provide intermolecular bonds which does not have to be collinear with the arms. Our main focus is on the effect of angular diameter of the interaction centers on the morphology of the simulated assemblies. Moreover, we explore the influence of molecular backbone symmetry on the periodicity and connectivity of the resulting adsorbed superstructures. The obtained results are compared with their selected counterparts from lattice MC simulations. It is demonstrated that a suitable choice of the size of the interaction centers and backbone aspect ratio allows for directing the self-assembly towards 2D networks comprising pores of different size and shape. The results from our theoretical modeling can be helpful in designing new functional organic building blocks able to form supramolecular networks with desired structural properties.

Thermodynamics of Rigid Self-Assembled Crystals: Molecular Simulation of Two-Phase Systems under External Fields

“…It reveals an important role of the next-nearest neighbor and three-body directional interactions in the self-assembly of the TMA adsorption layer. The obtained results have also shown that a quantitative assessment of the thermal stability of the structures and parameters of phase transitions in the TMA adsorption layer requires a smaller discretization of the lattice model. − Szabelski et al. ,,− have demonstrated that small changes in the molecule geometry, types, and positions of functional groups significantly affect the phase behavior of the adsorption layer. A common drawback of the lattice models is that the density of model structures does not change with the temperature and pressure, so the equation of state (EOS) is indefinite.…”

“…The most common are patchy-particle and lattice models. Analysis of the continuous patchy-particle models of SAMs − with a few exceptions , is focused on examining their structural characteristics rather than thermodynamic characteristics. Lattice models of SAMs have become more widespread due to their simplicity.…”

SuSMoST: Surface Science Modeling and Simulation Toolkit

“…There are lattice models of various degrees of abstraction: Langmuir adsorption model, hard disks, [6,7] dimers, [8][9][10][11] k-mers, [12,13] binary gasses, [14][15][16][17][18] molecules of various symmetry, [19][20][21][22][23] tricarboxylic [24][25][26][27] acids, porphyrins, [28] monoatomic adsobates, [29,30] and so forth. [31,32] In spite of numerous successful applications of lattice models, this kind of simulation is still not a daily tool for surface science researchers.…”

“…Therefore, the lattice with the set of possible site states constitutes the model of the adsorption system. There are lattice models of various degrees of abstraction: Langmuir adsorption model, hard disks, [ 6,7 ] dimers, [ 8–11 ] k ‐mers, [ 12,13 ] binary gasses, [ 14–18 ] molecules of various symmetry, [ 19–23 ] tricarboxylic [ 24–27 ] acids, porphyrins, [ 28 ] monoatomic adsobates, [ 29,30 ] and so forth. [ 31,32 ]…”

Short‐Range Structural Correlations in Amorphous 2D Polymers

“…Porous covalent polymers other than single‐layer COFs were reported to be generally amorphous, and Monte Carlo simulations were applied to disentangle how precursor mobility and surface reactivity influence structure growth . Independently, Monte Carlo simulations grant insight into the amorphous assembly of tripod‐shaped molecular building blocks confined to a surface . Defect densities in the form of pore‐size distributions were extracted from experimental data and the effect of the polymerization temperature was investigated .…”