Two components in a molecule:: Highly efficient and thermally robust catalytic system for CO2/Epoxide copolymerization
Two components in a molecule:: Highly efficient and thermally robust catalytic system for CO2/Epoxide copolymerization
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DOI：
10.1021/ja071290n
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发表时间：
2007-07-04
影响因子：
15
通讯作者：
Lee, Bun Yeoul
中科院分区：
文献类型：
--
作者：
Noh, Eun Kyung;Na, Sung Jae;Lee, Bun Yeoul
合成了一种含铵盐单元的水杨醛化合物[2-（HO）-3-tBu-5-{Bu 3 N+（CH 2）（3）Si（Me-2）} C6 H 2C（O）H][BF 4-]，并由此合成了Salen型配体及其钴（III）配合物（Salen-1）考克斯（1：Salen-1 = [trans-N，N'-bis（3-tBu-5-（Bu3N+（CH 2）（3）Si（Me-2）-salicylidene））-1，2-cyclohexanediamine）]X-2; X = 2，4-dinitrophenolate）。配合物1即使在高[环氧丙烷]/[催化剂]比和高达90 ℃的高温条件下也显示出对CO2/（环氧丙烷）共聚的高活性，在该条件下[（Salen）考克斯]/[PPNCl]的典型二元体系不产生任何共聚物。实现了非常高的TOF（高达3500 h（-1））和TON（高达14500），这在其他催化体系中从未实现过。该催化剂的另一个优点是对环状碳酸酯共聚物的高选择性（> 84%）和所得聚合物的高分子量（M-n = 53000-95000）。
Salicylaldehyde compound containing an ammonium salt unit, [2-(HO)-3-tBu-5-{Bu3N+(CH2)(3)Si(Me-2)}C6H2C(O)H][BF4-], is prepared from which a Salen-type ligand and its cobalt(III) complex, (Salen-1)CoX (1: Salen-1 = [trans-N,N'-bis(3-tBu-5-(Bu3N+(CH2)(3)Si(Me-2)-salicylidene)-1,2-cyclohexanediamine)]X-2; X = 2,4-dinitrophenolate), is prepared. Complex 1 shows high activity for CO2/(propylene oxide) copolymerization even at a condition of high [propylene oxide]/[catalyst] ratio and high temperature up to 90 degrees C, at which conditions a typical binary system of [(Salen)CoX]/[PPNCl] does not yield any copolymer. A very high TOF (up to 3500 h(-1)) and TON (up to 14500) are achieved, which have never been attained with other catalytic systems. The high selectivity (> 84%) for the formation of copolymer over cyclic carbonate and the high molecular weight of the obtained polymers (M-n = 53000-95000) are the other merits of the catalyst.