Al and Zn complexes bearing N,N,N-tridentate quinolinyl anilido-imine ligands: synthesis, characterization and catalysis in l-lactide polymerization
作者:Nan Yang、Lan Xin、Wei Gao、Jingshun Zhang、Xuyang Luo、Xiaoming Liu、Ying Mu
DOI:10.1039/c2dt30594a
日期:——
Reactions of N,N,N-tridentate quinolinyl anilido-imine ligands with AlMe3 afford mononuclear aluminum complexes κ3-[2-[ArNC(H)]C6H4}N(8-C9H6N)]}AlMe2 (Ar = 2,6-Me2C6H3 (1a), 2,6-Et2C6H3 (1b), 2,6-iPr2C6H3 (1c)) or dinuclear complexes AlMe3κ1-[2-[ArNC(H)C6H4]N(8-C9H6N)}-κ2]AlMe2 (R = 2,6-Me2C6H3 (2a), 2,6-Et2C6H3 (2b), 2,6-iPr2C6H3 (2c)) depending on the ratios of reactants used. Similar reactions of ZnEt2 with these ligands give the monoligated ethyl zinc complexes κ3-[2-[ArNC(H)]C6H4}N(8-C9H6N)]}ZnEt (Ar = 2,6-Me2C6H3 (3a), 2,6-Et2C6H3 (3b), 2,6-iPr2C6H3 (3c)) or bisligated complexes κ3-[2-[ArNC(H)]C6H4}N(8-C9H6N)]}Znκ2-[2-[ArNC(H)]C6H4}N(8-C9H6N)]} (Ar = 2,6-Me2C6H3 (4a), 2,6-Et2C6H3 (4b), 2,6-iPr2C6H3 (4c)). These complexes were well characterized by NMR and the structures of 1a, 2a, 2c, 3b and 4c were confirmed by X-ray diffraction analysis. The aluminum and zinc complexes were tested to initiate lactide polymerization in which the zinc complexes show moderate to high activities in the presence of benzyl alcohol.
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