首页> 外文OA文献 >Spin-spin coupling constants for iminoboranes RBNH, HBNR, and RBNR and comparisons with corresponding isoelectronic acetylenes RCCH and RCCR, for R = H, CH3, NH2, OH, and F
【2h】

Spin-spin coupling constants for iminoboranes RBNH, HBNR, and RBNR and comparisons with corresponding isoelectronic acetylenes RCCH and RCCR, for R = H, CH3, NH2, OH, and F

机译:亚氨基硼烷RBNH,HBNR和RBNR的自旋-自旋偶合常数以及与相应的等电子乙炔RCCH和RCCR的比较,其中R = H,CH3,NH2,OH和F

摘要

Ab initio equation-of-motion coupled-cluster singles and doubles method calculations have been performed on iminoboranes RBNH, HBNR, and RBNR, for R = H, CH3, NH2, OH, and F, to evaluate substituent effects on one- and two-bond 15N-11B, 11B-1H, and 15N-1H spin-spin coupling constants. For comparison purposes, 13C-13C coupling constants were evaluated for corresponding isoelectronic molecules RCCH and RCCR. The absolute values of 1J(N-B) and 1J(C-C) increase in the series HBNR and RCCH as the σ-electron-withdrawing ability of R increases. In contrast, NH 2 substitution at B leads to a decrease in the absolute value of 1J(N-B), but OH and F substitution increase 1J(N-B). Disubstitution has dramatically different effects on coupling constants for RCCR and RBNR. In the former, 1J(C-C) more than doubles relative to the corresponding RCCH and HCCH; in the latter, disubstitution of OH and F decreases 1J(N-B) relative to the corresponding monosubstituted derivatives, while NH2 substitution increases 1J(N-B). Changes in one- and two-bond B-H and N-H coupling constants upon substitution are similar to changes observed for 1J(N-B) in the corresponding monosubstituted derivatives RBNH and HBNR. © 2007 American Chemical Society.
机译:对于R = H,CH3,NH2,OH和F,对亚氨基硼烷RBNH,HBNR和RBNR进行了从头算运动方程耦合簇单打和双打方法计算,以评估取代基对一和二的影响键15N-11B,11B-1H和15N-1H自旋-自旋耦合常数。为了比较,评估了相应的等电子分子RCCH和RCCR的13C-13C耦合常数。 HBNR和RCCH系列中1J(N-B)和1J(C-C)的绝对值随R的σ电子吸电子能力的增加而增加。相反,B处的NH 2取代导致1J(N-B)的绝对值降低,而OH和F取代的绝对值增加1J(N-B)。取代对RCCR和RBNR的耦合常数有很大不同。在前一种情况下,相对于相应的RCCH和HCCH,1J(C-C)增加了一倍以上;在后者中,OH和F的分解相对于相应的单取代衍生物减少1J(N-B),而NH2取代增加1J(N-B)。取代后一键和二键B-H和N-H耦合常数的变化与相应的单取代衍生物RBNH和HBNR中1J(N-B)的变化相似。 ©2007美国化学学会。

著录项

相似文献

  • 外文文献

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号