Creation of low-dimensional molecular superstructures using two-in-one building blocks has been recently recognized as a practical alternative to conventional methods based on the self-assembly of binary (or multicomponent) mixtures of simple functional tectons. In this contribution, by means of coarse-grained Monte Carlo modeling, we study the on-surface self-assembly of functional tripod molecules equipped with terminal active centers of two types (1 and 2), providing directional intermolecular interactions. Our studies focus on the effect of preferred homotypic (1–1, 2–2) vs heterotypic (1–2) interaction mode on the structural properties of the resulting assemblies. Moreover, the role of the directionality of interactions on the self-assembly is examined for a complete set of isomers differing in the intramolecular distribution of the active centers. The results of the simulations demonstrate the formation of diverse superstructures, ranging from oligomers to networks, that can be directed by a suitable choice of the interaction mode and the intrinsic properties of a tecton at play. One of the general observations from these calculations is that under the heterotypic interaction mode, the growth of extended ordered molecular structures is greatly hindered, regardless of the type of isomer. The results of our theoretical investigations can be helpful in preliminary screening of molecular libraries to select optimal building blocks for the orthogonal self-assembly of molecular systems with presumed architecture and functions.
Paweł Szabelski (Tue,) studied this question.