Study On The Synthesis And Catalysis Of Dendritic Metal Complexes

A new kind of dendritic-salicylaldehydeimine ligand was synthesized with 1.0G polyamidoamine and salicylaldehyde through schiff reaction, and further formed three kinds of dendritic metal complexes by complexing Cu, Zn and Ni. The structure of dendritic-salicylaldehydeimine ligand and its metal complexes was characterized by elemental analysis, IR, NMR, XRD and UV. The imitated enzyme′s activity and ethylene oligomerization performance of dendritic Cu,Zn,Ni complex were also studied. Results showed that, dendritic Zn complex had no obvious imitated enzyme′s activity and ethylene oligomerization performance. So imitated enzyme′s catalytic kinetic performance of dendritic Cu complex and ethylene oligomerization performance of dendritic Ni complex were studied primarily in paper.With H₂O₂ as the oxidant, the oxidation reaction performance of dendritic Cu complex catalyzing ascorbic acid was determinated by spectrophotometry. Results showed that, dendritic Cu complex had good imitated enzyme activity; The catalytic kinetic model was established. The catalytic reactions conformed to pseudo-first-order reaction features, and with pH in 7.0⁷.5 and larger complexes concentration, the catalytic reaction rate could be obviously increased.Ethylene oligomerization performance was studied with dendritic Ni complex as main catalyst, MAO as cocatalyst and toluene as solvent. In addition, the influence of Al/Ni ratio, reaction temperature, reaction time, polymerization pressure on the ethylene oligomerization activity and a-olefins carbon number distribution of oligomerization products was examined. Results showed that the catalyst had good ethylene oligomerization performance, and reaction conditions had great influence on the ethylene oligomerization activity and a-olefins carbon number distribution of oligomerization product; Along with the increase of Al/Ni ratio, catalytic reactivity increased constantly, but when Al/Ni ratio was greater than 500, catalytic reactivity little changed, at the same time, with the increase of Al/Ni ratio, a-olefins carbon number directed to low carbon. With the reaction temperature increased, catalytic reactivity was reduced and a-olefins carbon number directed to low carbon.With the reaction time increased, catalytic reactivity fell rapidly and a-olefins carbon number directed to high carbon. With the increasing pressure for ethylene, catalytic reactivity increased, a-olefins carbon number directed to high carbon.