Synthesis,Structures And Catalytic Performance Of Aluminum And Tin Compounds Supported By Nitrogen-Containing Ligand

There has been continued research aimed at the discovery of metal compounds with N-aryl substituted?-diketiminato ligand or bis?amino?silane ligand as some of these compounds can be used as precursors in reactions with various small molecule substrates at the center and efficient homogeneous catalysts.This paper studied four metal-organic compounds stablied by the?-diketiminato ligand L¹H[HC?CMeNAr?₂,Ar=2,6-Et₂C₆H₃]or L²H[HC?CMeNAr?₂,Ar'=2,6-ⁱPr₂C₆H₃]and a tin compound supported by heterocyclic ligand L³H[Ph₂Si?NHAr?₂]were synthesized.The formation mechanism of the new two tin compounds with nitrogen-tin-carbon bonds and the catalytic properties of tin and antimony compounds supported by heterocyclic ligand were also discussed.The five new compounds listed in this paper were characterized by X ray single crystal diffraction,and their structures were also determined by ¹H NMR and ¹³C NMR.The main results were summarized as follows:1.The reaction of L¹AlH₂ with a substrate with the group of alcohol,results in L¹Al[??-O??o-C₆H₄?CN?2,6-ⁱPr₂C₆H₃?]₂?1?,while the reactions of the?-diketiminato ligand with SbCl₃,Me₂SnCl₂ and Me₃SnCl,result in L¹SbCl₂?2?,N?Ar?=C?Me?CH=C?NHAr?CH₂SnMe₂Cl·C₇H₈?3?and[N?Ar'?C?Me?=CHC?=NAr'?CH₂SnMe₂]₂·CH₂Cl₂?4?.Different from regular nitrogen-metal-nitrogen bonds generated by reactions of?-diketiminato ligands with metal halides,uncommon nitrogen-tin-carbon bonds were obtained in compounds 3 and 4.The latter is a rare tin dimer with eight-membered ring Through the comparison of two tin structures,the formation mechanism of dimer 4 has been investigated.2.The synthesis and catalytic properties of tin and antimony compounds supported by heterocyclic ligand were described.Among which,a new tin compound L³?SnMe₃?₂?5?were obtained by the reaction of L³Li₂[Ph₂Si?NLiAr?₂]with Me₃SnCl.Besides,[Ph₂Si?NAr'?₂]HSnMe₃?6?and[Ph₂Si?NAr'?₂]HSbCl₂?7?show different activities for ROP of caprolactone.It was observed that the catalytic activity of the two compounds varied depending on the metal center,and the tin center shows more excellent catalytic properties.