Pnictogen effects on the electronic interactions in the Lewis pair complexes Ph3EB(C6F5)3 (E = P, As, Sb)

Abstract

Lewis pair complexes bearing a BR3 acid and a R’3E base (E = P, As, Sb; R, R’ – organic ligands) play key roles in modern chemistry and technology, their properties being strongly relevant to catalysis and material science. The donor acceptor complexes Ph3EB(C6F5)3 attract special interest due to the elongated E-B bond that shifts the molecular parameters towards those of a frustrated Lewis pair. In depth theoretical and experimental studies of the Ph3EB(C6F5)3 systems presented in this work provide new insights into the nature of intramolecular electronic interactions in these molecules. A missing X-ray structure of Ph3AsB(C6F5)3 is described. Analyses of molecular structures, orbitals, dissociation energies and electron density distributions reveal crucial influence of non-covalent interactions on the Ph3EB(C6F5)3 stability.