Studies On The Synthesis And Catalytic Properties Of The Dendritic Complexes

The thesis consists of three parts as follows: Part I: ReviewIt look back to the development of the dendrimer from the view of the three aspects such as the synthesis, the functionalization study as well as the catalytic application of the dendrimer. The summaries on the typical chemical approaches used in the synthesis of the polymer as well as the methods for the functional studies of the synthesized polymer were given in this part. The main application of these metal-containing dendrimer in much chemical processes was emphasized, too. As a kind of newly synthesized polymer, their prospect and the problems they faced were also discussed in this part. Part II: The synthesis and the characterizing of the ligands and the complexesThe well known dendrimer PAMAM (abbreviated as polyamidoamine) is used as the initiator, and the reaction between PAMAM and SA (abbreviated as salicyaldehyde) gives the schiff-base like ligands PAMAMSA for the coordination with many metal ions such as FeJ+, Co2+, Ni2+, Mn2+, Cu2+, Zn2+, the 36 denddritic complexes PAMAMSA (1-6)-M (M=FeJ+, Co2+, Ni2+, Mn2+, Cu2+, Zn2+, respectively) were then obtained. Their structures were characterized by means of IR, ICP It was confirmed that the complexes have been prepared through the chemical reactions. Part III: The catalytic properties of the PAMAMSA-M complexesThe part consists of three subsections. The complexes were first used as catalysts for the oxidation of cyclohexene (the first subsection), isopropylbenzene (the second subsection) and ethylbenzene (the third subsection) by molecular oxygen in mild conditions. Their catalytic properties for the three-oxidation processes were investigated. The effects of the time, the temperature, the ratio of catalyst to substrate, the solvent as well as the additives to the reactions were also discussed in each of the three subsections, respectively. The comparison of the products selectivity, the conversion of the substrate, the molar oxygen absorption amount of the catalysts for the same substrate among different oxidation processes was employed to find out the optimum condition for theoxidation of each of three processes.The results of the oxidation of the cyclohexene show that all the 36 dendritic complexes exhibit promising catalytic properties for the substrate, and 7-Oxabicyclo[4,l,0]heptane, 2-Cyclohexen-l-ol, 2-Cyclohexen-2-one and 7-Oxabicyclo [4,l,0]heptan-2-one are given as major products. The product 7-Oxabicyclo [4,1,0] heptan-2-one was first observed via such process, and it is thought to be of something important for some organic synthesis as well as pharmaceutical synthesis.The isopropylbenzene are oxidized by PAMAMSA(l-6)-Fe3, PAMAMSA(1-6) -Co2+, PAMAMSA(l-6)-Ni2+, PAMAMSA(l-6)-Mn2+ , PAMAMSA(l-6)-Cu2+ catalysts and acetophenone, 1,1-dimethylbenzenmethanol are given as major products. It is showed by GC determination that the total selectivity of the products is well. With the changing of some factors, it was considered to afford single product.The ethylbenzene are also oxidized with the former catalysts except the PAMAMSA(5-6)-Ni2+ and PAMAMSA(l-6)-Ni2+ complexes. The major products of the oxidation are benzaldehyde and acetophenone. The total products selectivity of the oxidation is the highest among the three substrates. Much of the total selectivity reaches to 100% in the procession. It is also considered that the idealized oxidation process, that is, the single product can be arrived though the varying of some factors.