...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Dalton transactions: An international journal of inorganic chemistry >Thermodynamics of complexation reactions of borate and phenylboronate with diol, triol and tetritol
【24h】

Thermodynamics of complexation reactions of borate and phenylboronate with diol, triol and tetritol

机译：硼酸酯和苯基硼酸酯与二醇，三醇和四醇的络合反应的热力学

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

In order to fully elucidate the structures and stabilities of borate and phenylboronate complexes with polyols, the complexations with 1,2-ethanediol, 1,3-propanediol, 1,2,3-propanetriol, erythritol and threitol were investigated by NMR spectroscopy and DFT calculations. For the borate, 1:1 complexes binding with a ligand in a monodentate manner and 1:2 complexes binding with one ligand in an α,β- or α,γ-bidentate manner and the other in a monodentate manner were identified for the first time besides the well-known 1:1 and 1:2 complexes with five- and/or six-membered chelate rings. In addition, the formations of 1:1 α,β,δ-tridentate complexes with tetritol were confirmed. For the phenylboronate, the bidentate and tridentate complexes with 1:1 stoichiometries were identified. These complexations were enthalpy-driven processes accompanied by a negative entropic contribution. Linear enthalpy-entropy compensation relationships were observed for the stepwise complexations of borate and phenylboronate to form a five- or six-membered chelate ring. The TΔS° vs. ΔH° plots gave three different straight lines in parallel with one another depending on the number of OH groups outside the chelate ring. For the second intramolecular chelation to form the α,β,δ-tridentate complex from the α,β- or α,γ-bidentate complex with tetritol, the TΔS° vs. ΔH° plots gave different straight lines for the borate and phenylboronate, being more favorable in enthalpy for the phenylboronate.
机译：为了充分阐明硼酸酯和苯基硼酸酯与多元醇的结构和稳定性，通过NMR光谱和DFT研究了与1,2-乙二醇，1,3-丙二醇，1,2,3-丙三醇，赤藓醇和苏糖醇的配合物计算。对于硼酸盐，首先确定了以单齿方式与配体结合的1：1复合物和以α，β-或α，γ-二齿方式与一个配体结合的1：2复合物，以及以单齿方式与另一种配体结合的1：2复合物。时间是众所周知的带有五元和/或六元螯合环的1：1和1：2络合物的时间。另外，证实了与四糖醇的1：1α，β，δ-三齿复合物的形成。对于苯基硼酸酯，已鉴定出化学计量比为1：1的二齿和三齿复合物。这些复杂的过程是由焓驱动的，伴随着负熵的贡献。对于硼酸酯和苯基硼酸酯的逐步络合形成五元或六元螯合环，观察到线性的焓-熵补偿关系。 TΔS°对ΔH°图根据螯合环外的OH基团的数目给出了三个彼此平行的不同直线。对于第二次分子内螯合反应，由四醇与α，β-或α，γ-二齿配合物形成α，β，δ-三齿配合物，TΔS°与ΔH°曲线给出了硼酸盐和苯基硼酸酯的不同直线，对苯硼酸酯的焓更有利。

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