1581292-76-3Relevant academic research and scientific papers
Synthesis of γ-amidine-functionalized dianionic β-diketiminato lanthanide amides and trianionic β-diketiminato Na/Sm heterobimetallic complexes and their reactivity in polymerization of l-lactide
Liu, Peng,Chen, Hongxia,Zhang, Yong,Xue, Mingqiang,Yao, Yingming,Shen, Qi
, p. 5586 - 5594 (2014)
The readily accessible dianionic β-diketiminato lanthanide amido complexes LnLN(SiMe3)2(THF) (L = {(2,6-iPr 2C6H3)NC(CH2)CHC(CH 3)N(2,6-iPr2C6H3)} 2-) show an unprecedented reactivity toward carbodiimides. The reaction with N,N′-dicyclohexylcarbodiimide (DCC) led via [4 + 2] cycloaddition to γ-amidine-functionalized dianionic β-diketiminato lanthanide amido complexes, LnL1N(SiMe3)2 (L1 = {[(NHC6H11)(NC6H 11)C]HC[C(CH2)N(2,6-iPr2C 6H3)]2}2-, Ln = Sm(1), Yb(2), Y(3), Gd(4)). Conversion of a mixture of SmLN(SiMe3)2(THF) and NaN(SiMe3)2 with carbodiimide furnished the heterobimetallic complexes of Sm/Na with a novel amidinate-functionalized trianionic β-diketiminate ligand, [Na(DME)2](μ-L 2)[SmN(SiMe3)2] (L2 = {[C(N iPr)2]HC[C(CH2)N(2,6-iPr 2C6H3)]2}3-, DME = dimethoxyethane) (5) for N,N′-diisopropylcarbodiimide (DIC) and [Na(DME)3]+[SmL3N(SiMe3) 2]- (L3 = {[C(NCy)2]HC[C(CH 2)N(2,6-iPr2C6H3)] 2}3-) (6) for DCC. Molecular structures of complexes 1-6 were determined by an X-ray single crystal structure analysis. Complexes 1-4 were found to be highly active initiators of the ring-opening polymerization (ROP) of l-lactide (l-LA). The activity depended on the central metal with the increasing sequence of Yb w/Mn = 1.08-1.13) with the M n (average number molar mass) decreasing with increasing amount of BnOH proportionally. This journal is the Partner Organisations 2014.
