Evaluation of Enthalpy Change and Activation Enthalpy of the Reaction of Metal Complexes in Solution

溶液中金属配合物反应的焓变和活化焓的评价

• 批准号: 09640662
• 负责人: AIZAWA Sen-ichi
• 金额: $ 1.79万
• 依托单位: Shizuoka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640662/
• 关键词: Alkylamine; Octahedral-tetrahedral equilibrium; Ligand field stabilization energy; Energy level in spherically symmetric field; Electronic repulsion; Solvent exchange reaction; Activation Enthalpy; 溶媒交換反応速度; Alkylamine; Octahedral-tetrahedral equilibrium; Ligand field stabilization energy; Energy level in spherically symmetric field; Electronic repulsion; Solvent exchange reaction; Activation Enthalpy; 溶媒交換反応速度

The enthalpy differences (DELTAH^0) of the unique equilibrium between octahedral and tetrahedral cobalt(II) ion have been obtained in some primary alkylamine such as n-propylamine (pa, 36.1*2.3 kJ mol^<-1>), n-hexylamine (34.9*1.0 kJ mol^<-1>), 2-methoxyethylamine (meea, 44.8*3.1 kJ mol^<-1>), and benzylamine (50.1*3.6 kJ mol^<-1>). The differences between energy levels of the six- and four-coordinate Co(II) complexes in the spherically symmetric field (DELTAE_<spher>) in the primary alkylamine solvents have been estimated from the values of deltaH^0 by offsetting the ligand field stabilization energies for the octahedral and tetrahedral geometries obtained from the absorption spectral data. It has been confirmed that the values of DELTAE_<spher> is the decisive factor to determine the value of DELTAH^0 and is largely dependent on the electronic repulsion. This concept has been applied to the discussion about difference in energy levels between ground state and dissociative transition state of the solvent exchange reaction. The comparison between activation enthalpy (DELTAH^*) of the solvent exchange reaction of cobalt(II) ion in pa and meea has experimentally revealed that unexpectedly large rate constants of cobalt(II) ion in pa is attributed to small. DELTAH^* value which results from the strong electronic repulsion in the ground state.

八面体和四面体钴（II）离子之间独特平衡的焓差（Deltah^0）已在某些原发性烷基胺（例如N-丙酰胺）（Pa，36.1*2.3 kJ mol^<-1>），n-己胺（N-甲基胺，N-甲基胺（34.9*1.0 kJ Mol^-1 <-1），2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-MITH，2-METH 44.8*3.1 kJ mol^<-1>）和苄胺（50.1*3.6 kJ mol^<-1>）。已经从三角中^0的原烷基胺溶剂中估计了球形对称场（Deltae_ <spher>）中六坐标和四坐标CO（II）复合物之间的能量水平（II）之间的差异，这是通过从Deltah^0的值中估计的，从而抵消了八面和三次甲基苯二甲酸内层的配体现场稳定能量的配体稳定能量，从而吸收了该数据。已经证实，Deltae_ <spher>的值是确定Deltah^0值的决定性因素，并在很大程度上取决于电子排斥。该概念已应用于溶剂交换反应的基态和分离过渡状态之间能量水平差异的讨论。 PA和MEEA中钴离子（II）离子的溶剂交换反应的激活焓（Deltah^*）的比较表明，PA中钴（II）离子的出乎意料的大速率常数归因于小。 deltah^*值是由基态的强电子排斥产生的。