(-)-双(薄荷基甲酰基)苯基氧化膦的合成及在自由基光聚合中的螺旋选择性

以苯基二氯化膦和薄荷基甲酸为原料, 合成了一种手性双酰基膦氧化物光引发剂(-)-双(薄荷基甲酰基)苯基氧化膦. 采用核磁共振谱、 质谱及元素分析确定了该化合物的结构, 并测定了其螺旋诱导能力. 结果表明, (-)-BMPPO在引发自由基光聚合大位阻的单体甲基丙烯酸-1-苯基二苯并环庚酯(PDBSMA)的反应中具有螺旋选择性. 所得聚合物具有高度全同结构并显示出光学活性, 说明该聚合物形成了稳定的单手性螺旋链构象. 降低单体与引发剂的投料比及提高聚合温度有利于增加反应的螺旋选择性. 在手性薄荷醇溶剂中, 由(2,4,6-三甲基苯甲酰基)二苯基氧化膦(TPO)引发单体PDBSMA的光聚合反应也具有螺旋选择性, 但螺旋选择性很小.

Synthesis of Chiral (-)-Bis(menthylformyl)phenylphosphine Oxide and Its Helix-sense-selective Initiating Function for Radical Photopolymerization

In order to synthesize chiral bisacylphosphine oxide photoinitiator and investigate its excess one-handed helicity induction ability,(-)-bis(menthylformyl)phenylphosphine oxide(-)-BMPPO] was synthesized from P,P-dichlorophenylphosphine and(-)-menthylformic acid.The structure of the compound was confirmed by NMR,MS and elemental analysis.The results showed that(-)-BMPPO had helix-sense-selective ability in the initiating the radical photopolymerization of bulky monomer 1-phenyldibenzosuberyl methacrylate(PDBSMA).Highly isotactic,optically active polymers having a helical conformation with one-handed helicity were obtained.Lower feed ratio of the monomer to initiator and higher polymerization temperature were favorable to the increase of the helix-sense-selectivity.The photopolymerization of PDBSMA in chiral menthol initiated by(2,4,6-trimethylbenzoyl)diphenylphosphine oxide(TPO) was also helix-sense-selective,but the helix-sense-selectivity was less.