Parametrization of a Force Field for Te−N Secondary Bonding Interactions and Its Application in the Design of Supramolecular Structures Based on Heterocyclic Building Blocks

Abstract

1,2,5-Telluradiazole rings have a remarkably strong tendency toward association through Te−N secondary bonding interactions in the solid state. The reproducibility of the bond lengths and angles in the known crystal structures allowed the parametrization of an anharmonic force field to accommodate both the inter- and intramolecular Te−N bonds. The new parameters were tested against published crystal structures and were able to accurately reproduce the experimentally observed geometries. The incorporation of these parameters into a molecular mechanics force field enables the modeling of large and complex structures with significantly less computational effort than Hartree−Fock (HF) or density functional theory (DFT) methods. Simple modifications to the parameter set allowed the modeling of the structures of acyclic tellurium diamides. A series of 4,7-disubstituted benzo-2,1,3-telluradiazoles were modeled to probe the steric barrier of dimerization; only the groups with large spherical bulks such as t-butyl, trimethylsilyl, and adamantyl were able to destabilize the dimers. Modeling based on bifunctional building blocks suggests strategies for the construction of novel two- and three-dimensional supramolecular architectures.