title: Spin-orbit contributions in high-spin nitrenes/carbenes: a hybrid CASSCF/MRMP2 study of zero-field splitting tensors.
abstract: Zero-field splitting (ZFS) tensors (D tensors) of organic high-spin oligonitrenes/oligocarbenes up to spin-septet are quantitatively determined on the basis of quantum chemical calculations. The spin-orbit contributions, D(SO) tensors are calculated in terms of a hybrid CASSCF/MRMP2 approach, which was recently proposed by us. The spin-spin counterparts, D(SS) tensors are computed based on McWeeny-Mizuno's equation in conjunction with the RODFT spin densities. The present calculations show that more than 10% of ZFS arises from spin-orbit interactions in the high-spin nitrenes under study. Contributions of spin-bearing site-site interactions are estimated with the aid of a semi-empirical model for the D tensors and found to be ca. 5% of the D(SO) tensor. The analysis of intermediate states reveal that the largest contributions to the calculated D(SO) tensors are attributed to intra-site spin flip excitations and delocalized π and π* orbitals play an important role in the inter-site spin-orbit interactions.
authors: Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors: Kenji
authors: K
authors: Sugisaki
authors: Kazuo
authors: K
authors: Toyota
authors: Kazunobu
authors: K
authors: Sato
authors: Daisuke
authors: D
authors: Shiomi
authors: Masahiro
authors: M
authors: Kitagawa
authors: Takeji
authors: T
authors: Takui