Theoretical and experimental studies on the coordination ability of 1,4-bis(dimethylphosphinylmethyleneoxy)benzene

Combined experimental and theoretical study of the crystal, molecular and electronic structure, and coordination ability of 1,4-bis(dimethylphosphinylmethyleneoxy)benzene was performed using X-ray single-crystal analysis, FT-IR spectral characterization and quantum chemical calculations. The title compound crystallizes in the triclinic crystal system, P-1 space group. The asymmetric unit consists of two symmetrically independent molecules. The optimization of the molecular structure of the compound in gas phase at different levels of theory (ab initio, RHF/6-311G(d), MP2/6-311G(d) and DFT B3LYP/6-311G(2df,2p)) shows existence of several conformers. In the description of the conformers, a torsion angle CAr-CAr-O-C was used. The results from the optimized molecular structures are compared with the X-ray single crystal data. The electronic structure of the most important for the coordination ability molecular fragments, was described in terms of Natural Bond Orbitals (NBO) analysis and Mulliken charges.