首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Contributions from atomic p(Se), d(Se), and f(Se) orbitals to absolute paramagnetic shielding tensors in neutral and charged SeHn and some oxides including the effect of methyl and halogen substitutions on sigmap(Se)
Authors:Nakanishi Waro  Hayashi Satoko  Narahara Kenji  Hada Masahiko
Institution:Department of Material Science and Chemistry, Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510 (Japan). nakanisi@sys.wakayama-u.ac.jp
Abstract:Contributions from atomic p(Se), d(Se), and f(Se) orbitals to sigmap(Se) are evaluated for neutral and charged Se*Hn (*=null, +, or -) and some oxides to build the image of the contributions. The effect of methyl and halogen substitutions is also examined employing RrSe*XxOo (*=null, +, or -) where R=H or Me; X=F, Cl, or Br. The p(Se) contributions are larger than 96 % for SeH- (Cinfinityv), SeH2 (C2v), SeH3 + (C3v), SeH3 + (D3h), and SeH4 (Td). Therefore, sigmap(Se) of these compounds can be analyzed based on p(Se). The p(Se) contributions are 79-75 % for SeH4 (TBP), SeH5 + (TBP), SeH5 + (SP), and SeH5 - (SP). Methyl and halogen substitutions increase the contributions by 1-2 % (per Me) and 4-7 % (per X), respectively. The contributions are 92-79 % for H2SeO (Cs), H2SeO2 (C2v), and H4SeO (C2v). The values are similarly increased by the substitutions. Consequently, sigmap(Se) of these compounds can be analyzed based on p(Se) with some corrections by d(Se). The p(Se) contribution of SeH6 (Oh) is 52 %: sigmap(Se: SeH6 (Oh)) must be analyzed based on both p(Se) and d(Se). The contributions for the Me and X derivatives of SeH(6) amount to 86-77 %. Therefore, sigmap(Se) of the derivatives can also be analyzed mainly based on p(Se) with some corrections by d(Se). Contributions from f(Se) are negligible. Contributions from 4p(Se) in vacant orbitals are also considered. A utility program derived from the Gaussian 03 (NMRANAL-NH03G) is applied to evaluate the contributions.
Keywords:ab initio calculations  absolute shielding tensors  NMR spectroscopy  selenium
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号