...
  • 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, B. Condensed matter, materials, surfaces, interfaces & biophysical >Formation Constants and Conformational Analysis of Carbamates in Aqueous Solutions of 2-Methylpiperidine and CO2 from 283 to 313 K by NMR Spectroscopy
【24h】

Formation Constants and Conformational Analysis of Carbamates in Aqueous Solutions of 2-Methylpiperidine and CO2 from 283 to 313 K by NMR Spectroscopy

机译：用NMR光谱法通过283至313k的2-甲基哌啶和CO 2水溶液中氨基氨基酸盐的形成常数和构象分析

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

Quantitative C-13 nuclear magnetic resonance (NMR) spectroscopy was used to investigate the speciation in (2-methylpiperidine + H2O + CO2) systems at 283.2-313.2 K. The carbamate of 2-methylpiperidine(2-methylpiperidine-N-carboxylate) was shown for the first time to be a stable species in aqueous solutions. The spectroscopic results were used to obtain temperature-dependant formation constants for the carbamate using a simplified model for the activity coefficients from which the standard molar enthalpy of reaction was estimated. The results were incorporated into a self-consistent chemical equilibrium model, which includes vapor-liquid equilibria and all aqueous species, including the formation of carbamate. The predominant conformation of the sterically hindered carbamate, which was determined using two-dimensional exchange spectroscopy NMR, has the methyl group in the axial orientation and is in agreement with the density functional theory quantum chemical calculations.
机译：使用定量C-13核磁共振（NMR）光谱法在283.2-313.2K中研究（2-甲基哌啶+ H2O + CO2）系统的物种（2-甲基哌啶+ H2O + CO2）系统。2-甲基哌啶（2-甲基哌啶-N-羧酸盐）的氨基甲酸酯 第一次显示在水溶液中是稳定的物种。 光谱结果用于利用用于估计反应标准摩尔焓的活性系数的简化模型来获得用于氨基甲酸酯的温度依赖性地层常数。 结果掺入自我一致的化学平衡模型中，包括蒸气液平衡和所有水性物质，包括形成氨基甲酸酯。 使用二维交换光谱NMR测定的空间阻碍氨基甲酸酯的主要构象在轴向方向上具有甲基，并与密度泛函理论量子化学计算一致。

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