Synthesis and catalytic activity of Ln (III) complexes with an unsymmetrical Schiff base including multi“非汉字符号” C=N—groups

A synthetic method for a new unsymmetrical Schiff base and its Ln(Ⅲ)complexes including multi > C = N — groups is reported. The complexes are characterized byelemental analysis, IR spectra, ~1H and ^(13)C NMR, especially 2D-COSY ~1H, ~1H NMR spectra. Thegeneral formula of the obtained complexes is [Ln_3(TBLY)(NO_3)_3] · nH_2O (Ln = La, n = 3; Ln = Nd,n=5; Ln = Gd, Dy, Yb, Y, n = 7), where TBLY = tetraglycol aldehyde-2,4-dihydroxy benzaldehydebis-lysine Schiff base. In addition, the evidence for existence of > C = CH — NH — group issupported by the AM1 method. The complexes obtained may be used as a catalyst. Conversion rate of80% with the viscosity-average molecular weight 220000 for the polymerization of methyl methacrylate(MMA) without addition of any cocatalyst has been obtained.

A synthetic method for a new unsymmetrical Schiff base and its Ln (III) complexes in-cluding multi C == N— groups is reported. The complexes are characterized by elemental analysis, IR spectra, 1H and 13C NMR, especially 2D-COSY 1H, 1H NMR spectra. The general for-mula of the obtained complexes is [Ln3(TBLY)(NO3)3]·nH2O (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 C == CH—NH— 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.