1998 Fiscal Year Final Research Report Summary
Evaluation of Enthalpy Change and Activation Enthalpy of the Reaction of Metal Complexes in Solution
| Project/Area Number |
09640662
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Inorganic chemistry
|
|---|
| Research Institution | Shizuoka University |
|---|
Principal Investigator |
AIZAWA Sen-ichi Shizuoka University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (60231099)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Motoshi Shizuoka University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (80022242)
YAMADA Shinkichi Shizuoka University, Faculty of Engineering, Professor, 工学部, 教授 (60022737)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Keywords | Alkylamine / Octahedral-tetrahedral equilibrium / Ligand field stabilization energy / Energy level in spherically symmetric field / Electronic repulsion / Solvent exchange reaction / Activation Enthalpy |
|---|
| Research Abstract |
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.
|
Research Products
(13 results)
