Nonclassical B‐Hb⋯π interaction in diborane⋯localized‐π sandwiches: A DFT‐D3 study

Abstract

AbstractThe study presents a quantitative estimation of B‐Hb⋯π interaction in diborane‐localized‐π half sandwiches and sandwiches. DFT‐D3 method is used for geometry optimization and estimating the stability of the complexes (in terms of stabilization energies). The diborane molecule is the source of bridging hydrogen and O2, C2H4, and C2H2 molecules are considered as the localized π‐systems. MP2 and CCSD(T) calculations are also performed to measure the stability of the chosen complexes. Results indicate that the complexes are feebly stable in gas phase with stabilization energies <5.0 kcal mol−1. Compared to DFT‐D3 functionals, MP2 calculations are found to be more suitable in predicting the stability of the complexes. Dispersive interaction is the primary mode of interaction in stabilizing the complexes. Presence of substituents either on diborane or on the considered π‐systems play key role in stabilizing the complexes. Thermochemical analysis demonstrates the exothermic nature of complexation. 1H and 13B NMR analysis are also performed.