Aluminum Complexes Stabilized by Piperazidine-Bridged Bis（phenolate） Ligands： Syntheses, Structures, and Applica- tion in the Ring-Opening Polymerization of ε-Caprolactone  

作　　者：李文艺 姚英明 张勇 沈琪 

机构地区：[1]Key Laboratory of Organic Synthesis of Jiangsu Province,College of Chemistry,Chemical Engineering&Materials Science,Dushu Lake Campus,Soochow University,Suzhou,Jiangsu 215123,China

出　　处：《Chinese Journal of Chemistry》2012年第3期609-615,共7页中国化学（英文版）

摘　　要：The synthesis and characterization of aluminum alkoxide and alkyl complexes stabilized by piperazidine- bridged bis（phenolate） ligands are described. Treatment of ligand precursors Hz[ONNO]^1 {Hz[ONNO]^1= 1,4-bis（2-hydroxy-3-tert-butyl-5-methylbenzyl）piperazidine} and Hz[ONNO]2 {H2[ONNO]2=1,4-bis（2-hydroxy3,5-di-tert-butylbenzyl）piperazidine} with A1Et2（OCH2Ph） and A1Etz（OPr-i）, which were generated in situ by the reactions of AIEt3 with equivalent of the corresponding alcohols, in a 1： 1 molar ratio in THF gave the corresponding aluminum alkoxide complexes [ONNO]IAI（OCH2Ph） （1） and [ONNO]2Al（OPr-i） （2）, respectively. The reaction of H2[ONNO]^1 with A1Etz（OCHzPh） in a 1 ： 2 molar ratio in THF afforded a mixture of monometallic aluminum ethyl complex [ONNO] 1A1Et （3） and complex 1, which can be isolated by stepwise crystallization. Similarly, Hz[ONNO]2 reacted with A1Etz（OPr-0 in a 1： 2 molar ratio in THF to give a mixture of aluminum ethyl complex [ONNO]2AlEt （4） and complex 2. Complexes 1 and 2 were also available via treatment of complexes 3 and 4 with 1 equiv, of benzyl alcohol and isopropyl alcohol, respectively. All of these complexes were fully characterized including X-ray structural determination. It was found that complexes 1 to 4 can initiate the ring-opening polymerization of e-caprolactone, and complexes 1 and 2 showed higher catalytic activity in comparison with com- plexes 3 and 4.The synthesis and characterization of aluminum alkoxide and alkyl complexes stabilized by piperazidine- bridged bis（phenolate） ligands are described. Treatment of ligand precursors Hz[ONNO]^1 {Hz[ONNO]^1= 1,4-bis（2-hydroxy-3-tert-butyl-5-methylbenzyl）piperazidine} and Hz[ONNO]2 {H2[ONNO]2=1,4-bis（2-hydroxy3,5-di-tert-butylbenzyl）piperazidine} with A1Et2（OCH2Ph） and A1Etz（OPr-i）, which were generated in situ by the reactions of AIEt3 with equivalent of the corresponding alcohols, in a 1： 1 molar ratio in THF gave the corresponding aluminum alkoxide complexes [ONNO]IAI（OCH2Ph） （1） and [ONNO]2Al（OPr-i） （2）, respectively. The reaction of H2[ONNO]^1 with A1Etz（OCHzPh） in a 1 ： 2 molar ratio in THF afforded a mixture of monometallic aluminum ethyl complex [ONNO] 1A1Et （3） and complex 1, which can be isolated by stepwise crystallization. Similarly, Hz[ONNO]2 reacted with A1Etz（OPr-0 in a 1： 2 molar ratio in THF to give a mixture of aluminum ethyl complex [ONNO]2AlEt （4） and complex 2. Complexes 1 and 2 were also available via treatment of complexes 3 and 4 with 1 equiv, of benzyl alcohol and isopropyl alcohol, respectively. All of these complexes were fully characterized including X-ray structural determination. It was found that complexes 1 to 4 can initiate the ring-opening polymerization of e-caprolactone, and complexes 1 and 2 showed higher catalytic activity in comparison with com- plexes 3 and 4.

关 键 词：aluminum piperazine-bridged bis（phenolate） ligand synthesis crystal structure polymerization ε-caprolactone 

分 类 号：TQ254.15[化学工程—有机化工] TS513[轻工技术与工程—皮革化学与工程]