High cis-1,4-selectivity and activity coordination (co) polymerization of (polar) dienes by PNP-ligated rare-earth metal bis (aminobenzyl) complexes

Abstract

The research on the synthesis of cis-1,4-selective poly (conjugated diene)s catalyzed by the transition metal complexes has been actively pursued in both industrial and academic laboratories until today. However, there has not been any reported rare-earth catalytic system that can achieve the cis-1,4-selective polymerization of multiple conjugated dienes. Polar and non-polar conjugated dienes, as well as copolymerization of different kinds of conjugated dienes affording novel copoly (diene)s, are included. Herein, the highly cis-1,4-selective homopolymerization of a series of (polar)dienes (such as IP, MY, OC, 2-MOPB, 2-FPB) was achieved by using PNP ligated rare-earth metal bis (aminobenzyl) complexes PNP-Ln (Ln = Ln = Sc, Lu, Y, Gd, Sm, 1-5)/[Ph3C][B(C6F5)4]/Al i Bu3 ternary catalyst systems. Moreover, the highly cis-1,4-selective copolymerization of (polar)dienes (such as 2-MOPB and IP, 2-FPB and IP, MEPB and IP, OC and IP as well as 2-FPB and MY) with a board range of comonomers contenting and random or block sequence distribution was also achieved.