Synthesis of Poly(indene carbonate) from Indene Oxide and Carbon DioxideA Polycarbonate with a Rigid Backbone

The catalytic coupling of carbon dioxide with indene oxide utilizing (salen)Co(III)-2,4-dinitrophenoxide in the presence of an onium salt is presented. X-ray structural data for indene oxide monomer as well as cis-indene carbonate display near planarity of the fused cyclopentene and benzene rings. Low temperature (0 °C) is required to selectively afford copolymer vs cyclic carbonate from the coupling reactions of CO2 and indene oxide. The produced poly(indene carbonate) samples have molecular weights of up to 7100 Da, with corresponding glass transition temperatures of up to 134 °C, the highest yet reported for polycarbonates produced from CO2/epoxides coupling. Poly(indene carbonate) is thermally stable up to 249 °C. The polymerizations are well controlled, with PDI values ≤1.3.本工作报道了在鎓盐（onium salt）存在下，采用(salen)钴(III)-2,4-二硝基苯氧化物[(salen)Co(III)-2,4-dinitrophenoxide]催化二氧化碳与氧化茚的偶联反应。氧化茚单体与顺式茚碳酸酯的X射线晶体结构数据表明，二者的稠合环戊烯环与苯环均近乎平面结构。在二氧化碳与氧化茚的偶联反应中，需在低温（0 ℃）条件下才可选择性得到共聚产物，而非环状碳酸酯。所制备的聚(碳酸茚酯)样品分子量最高可达7100 Da，对应的玻璃化转变温度最高达134 ℃，该数值为目前已报道的二氧化碳与环氧化物偶联制备聚碳酸酯的最高值。聚(碳酸茚酯)的热稳定温度可达249 ℃。该聚合反应具有良好的可控性，多分散性指数（PDI, Polydispersity Index）≤1.3。