• 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 >Enthalpies of formation of hydrocarbons by hydrogen atom counting. Theoretical implications
【24h】

Enthalpies of formation of hydrocarbons by hydrogen atom counting. Theoretical implications

机译：通过氢原子计数形成烃的焓。理论意义

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

Standard enthalpies of formation at 298 K of unstrained alkanes, alkenes, alkynes, and alkylbenzenes can be expressed as a simple sum in which each term consists of the number of hydrogen atoms n of one of eight different types (n(1)-n(8)) multiplied by an associated coefficient (c(1)-c(8)) derived from the known enthalpy of formation of a typical molecule. Alkylbenzenes require one additive constant for each benzene ring, accounting for a possible ninth term in the sum. Terms are not needed to account for repulsive or attractive 1,3 interactions, hyperconjugation, or for protobranching, rendering them irrelevant. Conjugated eneynes and diynes show thermodynamic stabilizations much smaller than that observed for 1,3-butadiene, bringing into question the usual explanation for the thermodynamic stabilization of conjugated multiple bonds (p orbital overlap, pi electron delocalization, etc.).
机译：298 K时未应变的烷烃，烯烃，炔烃和烷基苯的标准形成焓可以表示为一个简单的总和，其中每个项由八种不同类型之一的氢原子数n（n（1）-n（ 8））乘以相关系数（c（1）-c（8）），该系数源自典型分子形成的已知焓。烷基苯的每个苯环都需要一个加成常数，占总数的第九个术语。不需要术语来说明排斥性或有吸引力的1,3相互作用，过度共轭或原分支，从而使它们无关紧要。共轭的炔和二炔显示出的热力学稳定性远小于1,3-丁二烯所观察到的热力学稳定性，这使对共轭多键（p轨道重叠，π电子离域等）的热力学稳定性的通常解释产生了疑问。

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