. All complexes were characterized by elemental analysis. Complex 1a, 2a,c, and 3a–c were characterized by X-ray crystallography, and complexes 2c,d were characterized by 1H and 13C NMR spectroscopy. The NHC complexes were efficient initiators for the ring-opening polymerization (ROP) of l-lactide (l-LA), with 2a giving the best catalytic activity. Imidazolinium-bridged lanthanide complexes 3a–c were
双
酚盐N-杂环卡宾(NHC)
镧系元素络合物[Ln(L)2 M](L = 1,3-双[O-4,6-di-tBu-C 6 H 2 -2-CH 2 ] [C(NCH 2 CH 2 N)],M = Li,Ln = Nd(1a); M = K,Ln = Nd(2a),Sm(2b),La(2c),Y(2d))由反应合成大号用KN(森达3)2和Nd [N(森达3)2 ] 3 -μ-CL-栗(THF)3或LN [N(森达3)2 ] 3(Ln = Nd,Sm,La,Y)。
咪唑啉桥双(
酚盐)
镧系元素络合物[Ln 2(L3)3 Cl 3 ](L3 = 1,3-双[O-4,6-di-tBu-C 6 H 2 -2-CH 2 ] [通过L3与Ln [N(SiMe 3)2 ] 3的胺消除反应合成CH(NCH 2 CH 2 N)] + Cl –,Ln = Sm(3a),Dy(3b),Er(3c))。或Ln [N(SiMe