羟胺酸钴配合物催化混合二甲苯的选择性氧化  

Selective catalytic oxidation of mixed xylene by hydroxamic acid cobalt complex Co(BPHA)_2

作　　者：陈骏如[1] 张瑞[1] 胡家元[1] 李贤均[1] 

机构地区：[1]四川大学化学学院有机金属络合催化研究所,四川成都610064

出　　处：《化学研究与应用》2002年第2期178-181,共4页Chemical Research and Application

摘　　要：合成并表征了羟胺酸配体N 苯甲酰基 N 苯基羟胺 (BPHA)及钴配合物Co(BPHA) 2 ,通过对反应过程的跟踪 ,证明 1∶1型超氧配合物Co(BPHA) 2 ·O2 是反应催化活性中间体。用该配合物为催化剂 ,以纯氧为氧源 ,在0 .5MPa压力下评价了不同的混合二甲苯液相催化氧化的活性 ,证明催化剂具有良好的活性 ,三种二甲苯反应活性大小的顺序为 :对 二甲苯 >邻 二甲苯 >间 二甲苯。当异构二甲苯 1∶1的比例下 ,反应温度 12 5℃ ,催化剂浓度 1.0× 10 - 3mol L时 ,反应 2小时 ,对 二甲苯氧化速度比间 二甲苯快 7倍 ,邻 二甲苯氧化速度比间 二甲苯快Hydroxamic acid cobalt complex Co(BPHA) 2 was synthesized and characterized by FT IR, 1H NMR,MS,TGA,DTA and UV.A series of experimental evidences strongly support that 1∶1 superoxide Co(BPHA) 2·O 2 is an active catalytic intermediate in the oxidation of xylene,which was detected by means of ESR and TF IR.Coordination of O 2 to Co(BPHA) 2 promotes the dioxygen's ability to abstract hydrogen atoms and to initiate radical reaction.The catalytic properties of Co(BPHA) 2 in the oxidation of mixed xylene with oxygen as the oxidant were investigated.Experimental results show that,for different xylene,the activities and selectivities are always high under mild reaction conditions.The catalytic activities and selectivities are related to the electronic and steric factors and oxidation rates of xylene are p xylene>o xylene>m xylene.

关 键 词：羟胺酸钴配合物 混合 二甲苯 活性中间体 催化氧化 选择性氧化 甲基苯甲酸 催化剂 

分 类 号：O625.511[理学—有机化学] O643.36[理学—化学]