- 作者: 賴錝裕 ; 劉育良 ; 舒克倫 等
- 作者服務機構: 清華大學化學系
- 中文摘要: Six tetraamine ligands, 2,5,8,11-tetraazadodecane, 2,5,9,12-tetraazatridecane, 3,7-dimethyl-3,7-diazanonane- 1,9-diamine, 2,6,9,13-tetraazatetradecane, 4,7-dimethyl-4,7- diazadecane-1,10-diamine, 4-methyl-4,7-diazadecane-1,10- diamine, and their nickel(II) complexes have been synthesized. The equilibrium constants and thermodynamic parameters of the high-spin---low-spin conversion of these complexes at various temperatures in 0.10M NaClO/sub 4/ have been investigated by spectrophotometric techniques. Influences of the enthalpies of these reactions are attributed to an endothermic contribution due to the breaking of the two Ni-OH/sub 2/ bonds, an exothermic contribution due to the strengthening of the four in-plane Ni-N bonds, an exothermic contribution due to the different ligand field stabilization energies of the square-planar and the octahedral complexes, an endothermic contribution due to the steric repulsions between the N-methyl group(s) and methylene groups as well as that between the two N-methyl group(s) and the coordinated water molecules, and an exothermic contribution due to the inductive effect of the N-methyl group(s). The important factors influencing the values of the entropies of these reactions are a negative term due to the reduction of spin multiplicity and a large positive term due to the release or the mobilization of the two coordinated water molecules.
- 英文摘要: --
- 中文關鍵字: Thermodynamics; High-Spin-Low-Spin Conversion; Nickel Complex; Tetraamine Ligand
- 英文關鍵字: 熱力學;高旋-低旋轉換;鎳錯合物;四胺基配位子