Synthesis and catalytic activity of Ln (<Emphasis Type="Bold">III</Emphasis>) complexes with an unsymmetrical Schiff base including multi groupsgroups

A synthetic method for a new unsymmetrical Schiff base and its Ln (III) complexes including multi groups is reported. The complexes are characterized by elemental analysis, IR spectra, ¹H and¹³C NMR, especially 2D-COSY ¹H, ¹H NMR spectra. The general formula of the obtained complexes is Ln₃(TBLY)(NO₃)₃]\sdnH₂O (Ln = La, n = 3; Ln = Nd, n=5; Ln = Gd, Dy, Yb, Y, n = 7), where TBLY = tetraglycol aldehyde-2,4-dihydroxy benzaldehyde bis-lysine Schiff base. In addition, the evidence for existence of group is supported by the AM1 method. The complexes obtained may be used as a catalyst. Conversion rate of 80% with the viscosity-average molecular weight 220000 for the polymerization of methyl methacrylate (MMA) without addition of any cocatalyst has been obtained.