Synthesis and magnetic resonance spectra of rare earth polynuclear complexes with aliphatic Schiff base

Among various factors affecting formation of polynuclear complex, steric hi ndrance is considered to be especially important. An aliphatic Schiff base (TAGL) from tetraglycol aldehyde and glycine offers a possible means to red uce steric hindrance. Some trinuclear rare earth complexes (Ln:L = 3: 1) we re synthesized and their formulas were established as [Ln(3)(TAGL)(NO3)(7)] CH3OH . nH(2)O (Ln = La, Nd, Sm, n = 1; Ln = Gd, Dy, Yb, Y, n = 2) by elem ental analysis, IR, NMR, etc. On the basis of EPR spectrum of the obtained Gd( III) complex, the crystal field strength is discussed. In addition, the proton signal of delta (HC=N) in this aliphatic Schiff base showed obvious upfield shift and appeared at similar to 5. 10, which made spectral assign ment much easier.