摘要
在碱的作用下,2,4-双(N-咪唑甲基)-6-取代苯酚(1)和2,6-双(N-咪唑甲基)-4—氯苯酚(2)与1,2-二溴乙烷、l,3-二溴丙烷、1,4-二溴丁烷或a,a’-二溴间二甲苯反应,合成了新型的模型配体(3～9).配体与[Cu(CH_3CN)_4]ClO_4反应,得到两个咪唑基与铜配位的双核铜蛋白模型化合物(10～16).研究了模型物的氧合作用,发现模型物15和氧气反应,发生分子内的羟化,生成μ- 酚氧基-μ-羟基的双核铜(Ⅱ)配合物,其它模型与氧气反应,生成双(μ-羟基)双核铜(Ⅱ)配合物.以4为例,详细研究了其模型物催化氧化苯偶姻的反应及反应动力学.考查了碱、外加配体、金属离子等对氧化反应的影响,发现模型物的活性是铜盐或单核铜配合物活性的近六倍.求出了反应的动力学参数Vmax、Km分别为9.47×10^(-5)·mol·dm^(-3)·s^(-1)和0.0418mol·dm^(-3),表明模型物催化的苯偶姻反应,遵从Michaelis-Menten动力学规律.
New ligands (3~9) containing four imidazolyls have been prepared efficiently by 2, 6- bis ( imidazolymethyl) - 4 - chlorophenol reaction with 1,2- dibromoethane, 1, 3 -dibromopropane, 1, 4 - dibromobutane or a, a' - dibromo - m - xylene. New binuclear copper protein models (10 ?16) in which two imidazolyls coordinate with each copper ion have been prepared also from the reaction of [Cu(CH3CN)4]ClO4 with ligands. The oxygenation of models has been studied. It's discovered that 13 complexes O2 and inserts one of oxygen atoms into the 2- position of m - xylyl spacer to form a phenolate and hydroxide bridge binuclear copper ( II )complex, the others react via four electrons reduction of the dioxygen molecule to give bis(μ -hydroxy) copper( II) complexes. The oxidation reaction of benzoin under the catalysis of the mimic system composed of the ligand and cuppric salt has been studied kinetically, the influence of basicities, additives and metal ions on reaction rate being examined. It's found that the m omposed of 4 in admixture with copper salt partakes efficiency 6 fold higher than that under the catalysis of copper salt alone. The reaction follows Michaelis - Menten saturation kinetic behaviorand the kinetic paraments Vmax, km are 9. 47 × 10-5mol·dm-3·s-1 and 0. 0418mol·dm-3 respectively.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1996年第3期304-312,共9页
Acta Chimica Sinica
基金
国家自然科学青年基金
教委博士点专项基金资助的课题
