...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >A Thermodynamic and Kinetic Characterization of the Solvent Dependence of the Saddle-Crown Equilibrium of Cyclotriveratrylene Oxime
【24h】

A Thermodynamic and Kinetic Characterization of the Solvent Dependence of the Saddle-Crown Equilibrium of Cyclotriveratrylene Oxime

机译：环戊四烯肟肟鞍-冠平衡的溶剂依赖性热力学和动力学表征

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The equilibration of the saddle conformer of cyclotriveratrylene (CTV) oxime to the corresponding crown conformer was followed by ~1H NMR in five separate solvents, and kinetic and thermodynamic parameters were determined from the NMR data. The oxime saddle conformers of 3 are favored in CDCl_3 (K_(eq) = [saddle]/ [crown] = 1.4), whereas the CTV oxime crown conformer 3a is favored in three more polar solvents studied (DMSO-d_6, acetonitrile-d_3, acetone-d_6). Surprisingly, the CTV oxime crown conformer is also slightly favored in the nonpolar solvent 1,4-dioxane-d_8. These behaviors are discussed in terms of hydrogen bonding, entropy, and possible host-guest considerations. An X-ray crystal structure was obtained for CTV monoketone, and structures of the different conformers of CTV, CTV ketone, and CTV oxime were calculated with semiempirical AMI methods for direct comparison of their ground-state energies.
机译：在五种单独的溶剂中，〜1H NMR监测环三亚戊二烯（CTV）肟的鞍型构象异构体与相应的冠状构象异构体的平衡，并根据NMR数据确定动力学和热力学参数。 CDCl_3（K_（eq）= [saddle] / [crown] = 1.4）偏爱3的肟鞍形构象异构体，而研究的另外三种极性溶剂（DMSO-d_6，乙腈-d_3）则偏爱CTV肟冠形构象异构体3a。 ，丙酮-d_6）。令人惊讶地，在非极性溶剂1，4-二恶烷-d_8中，CTV肟冠构型异构体也稍受青睐。这些行为是根据氢键，熵和可能的客体考虑来讨论的。获得了CTV单酮的X射线晶体结构，并使用半经验AMI方法计算了CTV，CTV酮和CTV肟的不同构象异构体的结构，以直接比较它们的基态能量。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

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