Electronic properties of tricoordinated phosphorus in hexagonal phosphininium compounds and molecular aromaticity.
Calculations with B3LYP within quantum chemical density functional theory have been carried out for 1-H-phosphininium cation and a series of 1-R-phosphininium molecules (R=cyclopentadiene, alpha and beta pyrroles, alpha and beta phosphole, C5BH5-- and CH2--). The negative nuclear-independent chemical shift values and the positive aromatic stabilization energies confirm that they are aromatic compounds. In particular, the 1-H-phosphininium cation even exhibits stronger aromatic character than the well-known aromatic phosphinine. The aromatic substituents have strong capability to attract electrons. It is the conjugation and aromaticity that keeps the stability and conformations of the molecules investigated. Owing to the perturbation of the aromatic substituted groups, the predicted large T values and the enlarged HOMO-LUMO gap of the phosphininium cation indicate that these compounds are expected in experiment.
Li
Wei-Qi
WQ
State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.
Tian
Wei-Quan
WQ
State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.|Department of Material Sciences, Faculty of Engineering Sciences, Kyushu University, 6-1 Kasugakoen, Kasuga, Fukuoka 816-8580, Japan.
Feng
Ji-Kang
JK
State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.|College of Chemistry, Jilin University, Changchun 130023, China.
Liu
Zi-Zhong
ZZ
State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.|Chemistry and Environment Science College, Inner Mongolia Normal University, Huhehaote 010022, China.
Ren
Ai-Min
AM
State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.
Sun
Chia-Chung
CC
State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.
Aoki
Yuriko
Y
Department of Material Sciences, Faculty of Engineering Sciences, Kyushu University, 6-1 Kasugakoen, Kasuga, Fukuoka 816-8580, Japan.