Nature of intramolecular interactions in hypercoordinate C-substituted 1,2-dicarba-closo-dodecaboranes with short P⋯P distances

Experimental (single-crystal X-ray diffraction) and computational evidence shows that there is short intramolecular distance between two phosphorus atoms in 1,2-(diphenylphosphino)-1,2-dicarba-closo-dodecaborane. In the optimized structure at the B3LYP/6-31G∗ level of theory the interaction was analyzed by quantum theory – atoms-in-molecules and natural bonding orbitals methods. Both methods established the interaction. The former method indicates direct P⋯P interaction, while the latter describes it as donor–acceptor interaction between phosphorus electron lone pair and adjacent antibonding P–C(phenyl) orbital.