Computational Study of van der Waals Complexes between Borylenes and Hydrocarbons

The addition of borylenes (RB) to prototypical carbon-carbon multiple bonds (ethyne, ethene) and the insertion into a C-H bond of methane involves weakly bound van der Waals complexes of the reaction partners according to computational chemistry methods. Geometries of all complexes were optimized using spin-component scaled second-order Moller-Plesset perturbation theory (SCS-MP2) in combination with a quadruple-zeta (def2-QZVP) basis set. Energies were further refined using the coupled-cluster (CCSD(T)) method in combination with basis sets up to quadruple-zeta quality (def2-QZVP and aug-cc-pVTZ). All of the complexes of borylenes studied correspond to shallow minima on their potential-energy surfaces. Borylene complexes with ethyne are the most stable and those with methane are the least stable ones. Aminoborylene complexes BNHR with ethyne and ethene are stabilized mainly by NH center dot center dot center dot pi interactions. Symmetry-adapted perturbation theory (SAPT) was performed to analyze the nature of the interaction between borylene molecules and hydrocarbons. Most of the ethyne complexes are dominated by electrostatic interactions, whereas for most of the ethene and all of the methane complexes the interaction is mainly dispersive.