Heterobimetallic Samarium(III) and Titanium(IV) Complexes with Bifunctional Catalytic Properties
journal contributionposted on 28.03.2011 by Fengying Zhou, Miaoshui Lin, Lei Li, Xueqing Zhang, Zhou Chen, Yahong Li, Yang Zhao, Jin Wu, Guimin Qian, Bin Hu, Wu Li
Any type of content formally published in an academic journal, usually following a peer-review process.
Reaction of the bis-ligand-chelated samarium complex [Sm(Hbptd)(H2bptd)] (1; H3bptd =1,9-bis(2-pyrrolyl)-2,5,8-triazanona-1,8-diene), in which a pyrrolyl ring is dangling and metal-free, with Ti(NMe2)4 yielded the heterometallic complex [Sm(Hbptd)(THF)(bptd)Ti(NMe2)2] (2). Treatment of the H3bptd ligand with 1 equiv of Ti(NMe2)4 gave the titanium amido complex [Ti(bptd)(NMe2)] (3). Complexes 2 and 3 were able to catalyze the hydroamination of phenylacetylene with 2,4-dichloroaniline and 4-methoxyaniline, and high regioselectivities were observed for the two amines. Both 1 and 2 were active catalysts for the ring-opening polymerization of ε-caprolactone. 2 showed higher activity for the polymerization reactions, due to a decrease in the coordination number of the samarium atom (from 9 in 1 to 8 in 2) by sharing its ligand with the titanium center.