Department of Chemistry, College of Staten Island and the Graduate Center of the City University of New York, Staten Island, New York 10314, USA.
J Am Chem Soc. 2012 Aug 15;134(32):13156-9. doi: 10.1021/ja302745t. Epub 2012 Aug 3.
Controlled Pd(0)/t-Bu(3)P-catalyzed Suzuki cross-coupling polymerizations of AB-type monomers via the chain-growth mechanism with an ArPd(t-Bu(3)P)I complex as the initiator are described. ArPd(t-Bu(3)P)I complexes, either prepurified or generated in situ from Pd(2)(dba)(3)/t-Bu(3)P/ArI (dba = dibenzylideneacetone) without separation/purification, were found to be efficient initiators in general for the controlled Suzuki cross-coupling polymerization, with narrow polydispersity indexes (PDIs) of 1.13-1.35 being observed. The Pd(2)(dba)(3)/t-Bu(3)P/p-BrC(6)H(4)I combination was identified as a highly robust initiator system, with PDIs of ≤1.20 in general and as low as 1.13 being obtained. Higher number-average molecular weights (M(n)) were achieved without a significant increase in the PDI (from 1.14 for a polymer with a M(n) = 9500 to 1.20 for a polymer with M(n) = 31,400) by using a smaller amount of the Pd(2)(dba)(3)/t-Bu(3)P/p-BrC(6)H(4)I initiator in the polymerization.
通过 ArPd(t-Bu(3)P)I 配合物作为引发剂，链增长机制控制 Pd(0)/t-Bu(3)P 催化的 AB 型单体的 Suzuki 交叉偶联聚合被描述。ArPd(t-Bu(3)P)I 配合物，无论是预先纯化的还是直接从 Pd(2)(dba)(3)/t-Bu(3)P/ArI（dba = 二苄叉丙酮）原位生成的，在控制Suzuki 交叉偶联聚合中通常都是有效的引发剂，观察到的多分散指数（PDI）窄，为 1.13-1.35。Pd(2)(dba)(3)/t-Bu(3)P/p-BrC(6)H(4)I 组合被确定为一个非常稳健的引发剂系统，一般PDI 小于等于 1.20，最低可达 1.13。通过在聚合中使用较少量的 Pd(2)(dba)(3)/t-Bu(3)P/p-BrC(6)H(4)I 引发剂，在不显著增加 PDI（从 PDI 为 1.14 的聚合物到 M(n)为 31400 的聚合物的 PDI 为 1.20）的情况下，实现了更高的数均分子量（M(n)）。
