Copolymerization of cyclohexene oxide and carbon dioxide using (salen)Co(III) complexes: synthesis and characterization of syndiotactic poly(cyclohexene carbonate)
Copolymerization of cyclohexene oxide and carbon dioxide using (salen)Co(III) complexes: synthesis and characterization of syndiotactic poly(cyclohexene carbonate)
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DOI：
10.1039/b513107c
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发表时间：
2006-01-01
影响因子：
4
通讯作者：
Coates, GW
中科院分区：
文献类型：
--
作者：
Cohen, CT;Thomas, CM;Coates, GW
描述了一系列新的 (salen) CoX (salen = N,N'-双(水杨基)-1,2-二氨基烷烃；X = 卤化物或羧酸盐)的合成路线，并描述了两种 (salen-1) CoX (salen-1 = N,N'-双(3,5-二叔丁基水杨基)-1,2-二氨基环己烷； 给出了 X = Cl, I) 配合物。 (R, R)-(salen- 1) CoX (X = Cl, Br, I, OAc, 五氟苯甲酸酯 (OBzF(5))) 催化剂对于环己烯氧化物 (CHO) 和 CO2 的共聚具有活性，产生间规聚(环己烯碳酸酯) (PCHC)，这是一种以前未报道的 PCHC 微观结构。 salen配体和反应条件的变化，以及[PPN] Cl（[PPN] Cl =双（三苯基膦）氯化亚胺）助催化剂的加入，对聚合速率和所得PCHC立构规整度具有显着影响。催化剂 rac-(salen- 6) CoX (salen- 6 = N,N'-双(3,5-二叔丁基水杨基)-1,2-二氨基丙烷; X = Br, OBzF(5)) 对 CHO/CO2 共聚具有高活性，可产生具有高达 81% r 中心四分体的间同立构 PCHC。使用伯努利统计方法，PCHC 四联体和三联体序列分别分配在这些聚合物的 C-13 NMR 谱中的羰基和亚甲基区域中。
Synthetic routes to a series of new (salen) CoX (salen = N, N'-bis(salicylidene)-1,2-diaminoalkane; X = halide or carboxylate) species are described and the X-ray crystal structures of two (salen-1) CoX (salen-1 = N, N'-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane; X = Cl, I) complexes are presented. (R, R)-(salen- 1) CoX (X = Cl, Br, I, OAc, pentafluorobenzoate (OBzF(5))) catalysts are active for the copolymerization of cyclohexene oxide (CHO) and CO2, yielding syndiotactic poly(cyclohexene carbonate) (PCHC), a previously unreported PCHC microstructure. Variation of the salen ligand and reaction conditions, as well as the inclusion of [PPN] Cl ([PPN] Cl = bis( triphenylphosphine) iminium chloride) cocatalysts, has dramatic effects on the polymerization rate and the resultant PCHC tacticity. Catalysts rac-(salen- 6) CoX (salen- 6 = N, N'-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminopropane; X = Br, OBzF(5)) have high activities for CHO/CO2 copolymerization, yielding syndiotactic PCHCs with up to 81% r-centered tetrads. Using Bernoullian statistical methods, PCHC tetrad and triad sequences were assigned in the C-13 NMR spectra of these polymers in the carbonyl and methylene regions, respectively.