Living Polymerization of Butadiene at Both Chain Ends via a Bimetallic Nickel Initiator. Preparation of Hydroxytelechelic Poly(butadiene) and Symmetric Poly(isocyanide-b-butadiene-b-isocyanide) Elastomeric Triblock Copolymers
作者:Timothy J. Deming、Bruce M. Novak、Joseph W. Ziller
DOI:10.1021/ja00085a016
日期:1994.3
967.50(15) [angstrom][sup 3]; and Z = 2. Refinement of the model, which contained a disordered C[sub 6]H[sub 8] unit, led to convergence with R[sub F] = 5.8%, R[sub WF] = 6.9%, and GOF = 2.21 for 276 variables refined against those 2852 data with [vert bar]F[sub o][vert bar]> 3.0[sigma]/([vert bar]F[sub o][vert bar]). The living polybutadiene samples were successfully used to prepare triblock copolymers
双功能镍引发剂,双(μ-trifluoroacetato)([η][sup 3]:[η[sup 3]-2,2[prime]-二烯丙基)二镍(II),IV,被合成以促进丁二烯活性聚合成具有两个链端活性的高顺式 1,4 含量聚合物。其他潜在的引发剂,[1,4-亚苯基双(([η][sup 3]-1-烯丙基)三氟乙酸镍)][sub n]、II和[1,4-环己烷二基双(([η][sup 3] ]-1-烯丙基)-三氟乙酸镍)][sub n], III 被发现是完全无效的,因为分子间的羧酸根桥给出了复合物的聚合结构。通过 X 射线晶体学证实了 IV 中的分子内桥及其分子结构。IV 在空间群 P[bar 1] 中与 0.5 当量的 2.3-双((三氟乙酰氧基)甲基)-1,3-丁二烯在晶胞中共结晶,常数为 a = 9.5600(8) [埃],b = 9。6554(9) [埃],c = 11.7615(10)