Synthesis, Characterization and Optical Properties of Metal Complexes Bearing Benzotriazole Phenoxide Derivatives: Catalysis for Ring-Opening Polymerization of Cyclic Esters and Carbon Dioxide/Epoxides Coupling and Copolymerization

• Main Authors: Chen-Yu Li, 李晨宇
• Other Authors: Chia-Her Lin
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/78186373281682964497

博士 === 中原大學 === 化學研究所 === 101 === Several novel metal complexes bearing BTP ligands (BTP = N,O-bidentate benzotriazole phenoxide), [{(-C1BTP)AlMe2}2] (1), [(C1BTP)2AlMe] (2), [(C1BTP)3Al] (3), [(C1BTP)2Al(OAn)] (4), [{(C1BTP)2Al}2(-O)] (5), [{(C1BTP)2Al(-OH)}2] (6), [(C1BTP)Al2Me5] (7), [(CMe2PhBTP)AlMe2] (8), [(t-BuBTP)AlMe2] (9), [(CMe2PhBTP)2AlMe] (10), [{(CMe2PhBTP)2Al}2(-O)] (11), [(TMClBTP)2Mg(THF)2] (12), [(CMe2PhBTP)2Al(NMe2)] (13), [(t-BuBTP)2Al(NMe2)] (14), [(TMClBTP)2Al(NMe2)] (15), [{(t-BuBTP)2Al}2(-O)] (16), [{(TMClBTP)2Al}2(-O)] (17), [(-C8BTP)Ti(OiPr)3]2 (18), [(C8BTP)2Ti(OiPr)2] (19), [(t-BuBTP)2Ti(OiPr)2] (20), [(TMClBTP)2Ti(OiPr)2] (21) and trimetallic complexes incorporated by amine-bis(benzotriazole phenolate) ligands, [(C1NNBiBTP)2Mg3(OBn)2] (22), [(C1PPBiBTP)2Mg3(OBn)2] (23), [(C1NNBiBTP)2Zn3(OAc)2] (24), [(C1NNBiBTP)2Co3(OAc)2] (25) and [(C1NNBiBTP)2Ni3(OAc)2(H2O)2] (26) were synthesized and structurally characterized. Their optical properties and catalytic activities in ring-opening polymerization (ROP) of lactone and carbon dioxide/epoxides coupling and copolymerization were systematic studied. Luminescent properties of complexes 1-3 and 5-7 in solution were studied, and it was found that the maxima emission wavelength (max) of 1-3 and 5-7 is in the range 492 to 500 nm and the quantum yield is 0.020-0.118, depending on the BTP ligands coordinating to the metal center. Experimental results demonstrated that complexes 4, 11/(9-anthracenemethanol (9-AnOH)), 12/9-AnOH, 15, 18 and 19 efficiently catalyze the ring-opening polymerization of -caprolactone (-CL) or/and L-lactide (L-LA) in a controlled fashion, yielding polymer with the expected molecular weights and narrow polydispersity indices (PDIs). Single-site Al amide 15 is an efficient initiator for the LA polymerizations with a living character, and the polymerization displays a first-order dependence on the L-LA concentration. Kinetic studies of ε-CL polymerization initiated by 18 were investigated using in situ 1H NMR spectroscopy; the polymerization exhibited first-order dependence on both complex 18 and ε-CL concentrations. Additionally, bimetallic BTP-ligated alumoxane 17 is an active catalyst (TOF: 120 h-1) for the coupling of CO2 with PO in the presence of n-Bu4NBr to give propylene carbonate under mild conditions. New trimetallic magnesium complexes bearing amine-bis (benzotriazole phenolate) were synthesized for bifunctional catalysis. Complex 22 catalysed -CL polymerizations in not only a ‘living’ manner but also in an ‘immortal’ fashion. Additionally, tri-Mg 22 was active for the coupling of CO2 with cyclohexene oxide (CHO) on addition of n-Bu4NBr co-catalysts to give cis-cyclohexene carbonate under mild conditions. A novel tri-Co 25 catalyst for the copolymerization of CHO and CO2 in controlled manner, yielding poly(cyclohexene carbonate) with the highly molecular weights and narrow PDIs (Mn = 10100, PDI = 1.39). The 25/n-Bu4NCl catalytic system shows good productivity (TON: 990) and activity (TOF: 495 h-1) under optimal conditions.