Studies On The Synthesis And Catalytic Hydrogenation Properties Of The Supported Dendritic Complexes At Room Temperature And Atmospheric Pressure

The thesis consists of three parts as follows:Part I: ReviewIn this part new progress in the field of dendrimers and hybranched molecules were collected . Owing to the muti-disciplinarity of dendrimer chemistry it seems to be important to focus on topical research, functions of dendrimers and their potential application, hi this part specific functionalization possibilities and their effects were discussed. Among the many interesting functional dendrimers, dendritic catalysts, photoactive,electro-active, bioactive dendrimers and the dendrimers of fullerene were concentrated on . Part II: The synthesis and characterization of the dendrimer ligands and complexesThe dendrimer PAMAM(Polyamidoamine dendrimer ,G=l-6) was grafted onto the surface of chrolomethyl polystrene. hi addition , functional reactions of salicyaldehyde and dichlorophenyl phosphine respectively with the terminal amino groups of the dendritic polymer-grafted chloromethyl polystrene were also investigated. The reactions of the above functional dendrimer ligands and PdCl2 had also been carried out, and we got a series of Schiff ligands(CIG,l-6G) and organic phosphine ligands(CIIC 1-6G). The dendrimer ligand and complex structures were characterized by XPS, IR, TG-DTA, and ICP. Part III: The catalytic hydrogenation properties of CIC,CIICThis part includes three sub sections. Section One: The results of the hydrogenation of nitrobenzene at normal pressure and room temperature in Chapter One indicated that the second generation of dendritic catalyst supported by chloromethyl polystrene showed the highest activity ; adding the NaOAc in the solution of reaction possessed postive effect on hydrogenation of substrates. Section Two: The results of the hydrogenation of benzylaldenyde to benzylacoholand three chlorobenzaldehyde isomers at normal pressure and room temperature in Chapter Two indicated that the second generation of catalyst CIC,CIIC also had the highest activity among the six catalysts; the optimum solvents for the hydrogenation reaction was alcohol. But the dichloromethane will poison the catalyst CIIC. The influence of the Pd/Fe atomic ratio on the selective hydrogenation of the substrates was remarkable, no hydrogenolysis of Cl atom (dechlorination ) occurred in the hydrogenation of dichloromethane. Section Three: The results of the hydrogenation of five-membered hetercycles by the catalyst CIC,CIIC at normal pressure and room temperature in Chapter Three indicated that The hydrogenation of pyrrole, furan, thiophene can be carried out till saturate smoothly by using the mixture solvents in the presence of protonic acids. The five-membered hetercycles were opened directly in the presence of CIC, but the sudstrates were hydrogenated completely to the corresponding saturated hetercycles in the presence of CIIC.