Synthesis, Structures And Catalytic Performance Of Aluminum(Sulfur, Oxygen, Nitrogen And Bromine) Compounds Supported By Diketiminato Ligand

The synthesis and catalytic performance of organoaluminium compounds stablied by the β-diketiminato ligand(L = HC{C(Me)N(Ar)}2, Ar=2,6-iPr2C6H3) was studied in this paper. And six novel heteroaluminum hybrid system compounds were synthesized. Besides the effects of the electronic and steric effects of the compounds on catalytic properties were also discussed and studied. All the new compounds listed in this paper were characterized by X ray single crystal diffraction, and their structures were also determined by 1H NMR and 13 C NMR. The main results were summarized as follows:(1) The reactions of LAlH2 with some substrate with the group of sulfhydryl, alcohols, and amines, respectively, result in five novel structure of aluminum compounds LAl[(μ-S)(m-C4N2H)(CH2)2]2(1),LAl[OH][(μ-S)(m-C4N2H)(CH2)2](2), LAl[(μ-O)(o-C6H4)CN(C5NH4)]2(3), LAlH[(μ-O)(o-C4H4)CN(2,6-iPr2C6H3)](4), and LAl[(μ-NH)(o-C8SH8)(COOC2H5)]2(5), and their catalytic performance were discussed as well. These compounds are the products of the condensation of dehydrogenation, compounds 3 and 4 have similar reaction substrates, but the molecular structure of the two is total different and two molecular structures conjugation toluene in 3, which can be attributed to the steric effect of the substrate. At the same time, a series of chemical reactions can be carried out with 4 for the high reaction activity of the hydrogen atoms, which provides a new method for preparation of compounds with unique structure and excellent properties. Al atoms are five coordinated in the compounds 1 and 5, which makes the compounds are more stable. compound 1 shows good catalytic performance as initiator for ring-open polymerization of ε-caprolactone; these four compounds were tested as a catalyst to catalytic aldehyde and trimethylsilyl cyanide addition reaction, the electronic and steric effect of the catalyst and electronic effect of the substrate were discussed to explore the different influence about the extent of the reaction in the experiment. This addition reaction in a certain extent provides the basis rules about selecting the catalyst for the reaction.(2) The reactions of LAl H2(L = HC(CMeNAr)2, Ar = 2,6-iPr2C6H3) with BBr3, result in a novel structure of aluminum bromide compound LAlBr2(5), The structure is four coordinated, the plane formed by the aluminum atom and two nitrogen atoms presented centrosymmetric with the plane formed by two bromine atoms which will help stabilize the molecule.