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合成了(S)-2,2’-二(溴甲基)-1,1’-联萘,(S)-2’-甲基-2-溴甲基-1,1’-联萘,α-溴代苯乙酸薄荷酯,N-薄荷基-α-溴代苯乙酰胺和α-溴代苯乙酸胆甾烷醇酯5种旋光的溴代烷并将其用作非手性单体甲基丙烯酸-1-苯基二苯并环庚醇酯(PDBSMA)的原子转移自由基聚合(ATRP)的手性引发剂.为了使这些手性引发剂在引发一步生成的初级自由基不发生消旋化,引发剂中的手性中心都不直接与溴原子相连.用这5种手性溴代烷做引发剂引发PDBSMA的ATRP所得聚合物可分成四氢呋喃(THF)可溶部分和THF不溶部分.THF可溶部分具有较大的比旋光度.对THF可溶部分的手性光学性质研究以及比较该部分聚合物和在同样引发条件下得到的甲基丙烯酸甲酯聚合物的比旋光度,我们得出聚合物大的比旋光度是由聚合物单手性螺旋过量引起的结论,即合成的手性引发剂对PDBSMA的ATRP均有一定的螺旋选择性,其中(S)-2,2’-二(溴甲基)-1,1’-联萘、(S)-2’-甲基-2-溴甲基-1,1’-联萘螺旋选择性最好.引发剂的螺旋诱导能力跟聚合反应的温度有很大关系,聚合温度上限为70℃,在0～70℃之间,随着温度的升高引发剂的螺旋选择性逐渐增强.
(S) -2,2’-bis (bromomethyl) -1,1’-binaphthyl, (S) -2’-methyl-2-bromomethyl-1,1’-binaphthyl, menthyl α-bromophenylacetate, N-menthyl-α-bromophenylacetamide, and cholesteryl α-bromophenylacetate were prepared and used as achiral monomers Chiral initiators of Atom Transfer Radical Polymerization (ATRP) of 1-phenyl dibenzosuberyl methacrylate (PDBSMA) In order for these chiral initiators not to cause primary radicals to be generated in one step to occur Racemization, none of the chiral centers in the initiator are directly linked to the bromine atom. ATRP with these 5 chiral brominated alkanes as initiator initiates PDBSMA The resulting polymer can be separated into a tetrahydrofuran (THF) soluble fraction and a THF insoluble Part.THF soluble part has a greater specific rotation.The study on the chiral optical properties of the THF soluble part and the comparison of the specific rotation of the part of the polymer and the methyl methacrylate polymer obtained under the same conditions , We conclude that the specific optical rotation of the polymer is caused by the excessive monomeric chirality of the polymer. That is, the synthetic chiral initiator has a certain degree of helix selectivity for the ATRP of PDBSMA. The (S) -2, 2’-bis Methyl) -1,1’-binaphthyl, (S) -2’-methyl-2-bromomethyl-1,1’-binaphthyl was the best. The helix-induced ability of the initiator was similar to that of the polymerization Of the temperature is greatly related to the polymerization temperature of the upper limit of 70 ° C, between 0 ~ 70 ° C, with increasing temperature, the initiator of the spiral selectivity gradually increased.