Kinetics and mechanism of ligand substitution in β-diketone complexes of iron(III). Solvolysis controlling the substitution process in alcohol media
作者:Gerhard Gumbel、Horst Elias
DOI:10.1016/s0020-1693(02)01143-x
日期:2003.1
Abstract Conventional and stopped-flow spectrophotometry was used to study the kinetics of ligand substitution in a number of tris β-diketone iron(III) complexes, Fe(O ∩ O) 3 , by 8-hydroxyquinoline (=HO ∩ N) in alcohol media (O ∩ O − =anion of the β-diketones pentane-2,4-dione, 2,6-dimethylheptane-3,5-dione, 2,2,6,6-tetramethylheptane-3,5-dione, 1-phenylbutane-1,3-dione, 1,3-diphenylpropane-2,3-dione
摘要用常规分流光度法和分流光度法研究了酒精中的8-羟基喹啉(= HO∩N)在许多trisβ-二酮铁(III)配合物Fe(O∩O)3中的配体取代动力学。介质(O∩O-=β-二酮戊烷-2,4-二酮的阴离子,2,6-二甲基庚烷-3,5-二酮,2,2,6,6-四甲基庚烷-3,5-二酮,1 -苯基丁烷-1,3-二酮,1,3-二苯基丙烷-2,3-二酮和1-(2-噻吩基)-4,4,4-三氟丁烷-1,3-二酮)。如分光光度法所示,络合物Fe(O∩O)3在醇ROH中的溶液会发生溶剂分解,从而形成溶剂型Fe(O∩O)2 S 2和双核络合物[Fe(O∩O)2 (RO)] 2(分别为S = ROH和RO-)。Fe(O∩O)3与HO∩N在醇介质中的反应导致Fe(O∩N)3的反应是三次的。相应的一阶速率常数k 1,k 2和k 3与进入配体HO∩N的浓度无关,并且遵循k 1> k 2> k 3的顺序,其中k 1 /