title: Theoretical study on the phenyl torsional potentials of trans-diphenyldiphosphene.
abstract: The phenyl torsional potentials of trans-diphenyldiphosphene ( trans-phosphobenzene; t-DPP), which is an analogue of trans-azobenzene ( t-AZB), have been examined by means of ab initio complete active space self-consistent field (CASSCF) calculations. Though the electronic structures of t-DPP are similar to those of t-AZB, the phenyl torsional potentials are different from each other. In S 0, the potential energy curve of t-DPP has double minima at nonplanar conformations with C 2 and C i symmetries, while that of t-AZB has only minimum at a planar conformation with C 2 h . In S 1, the phenyl torsion of t-AZB is impeded from a planar geometry more than that in S 0. On the other hand, the phenyl torsion of t-DPP is promoted so that the phenyl groups are perpendicularly twisted against the PP double bond around the Franck-Condon region. Comments on the experimental findings of realistic diphosphenes protected by bulky substituents are also made.
authors: Faculty of Engineering and Resource Science, Akita University, Tegata Gakuen-cho, Akita 010-8502, Japan. amatatsu@ipc.akita-u.ac.jp
authors: Yoshiaki
authors: Y
authors: Amatatsu
mesh_terms: D001391:Azo Compounds / Q000737:chemistry; D003198:Computer Simulation; D004583:Electrons; D008956:Models, Chemical; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry*; D011789:Quantum Theory; D013237:Stereoisomerism
chemical_list: D001391:Azo Compounds; D009943:Organophosphorus Compounds; C532938:trans-diphenyldiphosphene; C009850:azobenzene