Theoretical study on the relationship between spin multiplicity effects and nonlinear optical properties of the pyrrole radical (C4H4N.).
The geometrical structure and stability of neutral pi-conjugated C4H4N. with three spin states were investigated by using ab initio and density functional theory (DFT) methods. In addition, the linear and nonlinear optical properties were studied at the same level combined with the finite field approach. The calculated results show that conjugation and stability decreased with increasing spin multiplicity. These reliable UCCSD results show that the polarizability (alpha) values of C4H4N. with the quartet state are maximal, while those of C4H4N. with the doublet state are minimal. The order of betatot values is betasextet > betadoublet > betaquartet. The second hyperpolarizability (gamma) values exhibit positive values. The variation trends of gamma are consistent with alpha.
Qiu
Yong-Qing
YQ
Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, People's Republic of China. qiuyq466@nenu.edu.cn
Fan
Hong-Ling
HL
Sun
Shi-Ling
SL
Liu
Chun-Guang
CG
Su
Zhong-Min
ZM