Nine Ln( Ⅲ ) complexes with a novel Schiff base derived from diglycolamine and benzoylacetone (BZDA) have been synthesized and characterized. They can be formulated as [Ln2(BZDA)3(NO3)3](NO3)3· nH2O(Ln=La, Pr, N...Nine Ln( Ⅲ ) complexes with a novel Schiff base derived from diglycolamine and benzoylacetone (BZDA) have been synthesized and characterized. They can be formulated as [Ln2(BZDA)3(NO3)3](NO3)3· nH2O(Ln=La, Pr, Nd, Sm, n = 4; Ln=Gd, Tb, Er, Yb, Y, n = l). Enamic form mechanism in this β-diketone Schiff base and its complexes were suggested and proved by IR, UV and NMR methods. The 13C spin-lattice relaxation time T1 and the ratios of r(ci-Ln)/r(cj-Ln) were measured by a 500 MHz NMR instrument for elucidating the formation of the stable sk-membered chelate ring structure in these complexes. The EPR spectrum of the Gd( Ⅲ ) complex exhibits the 'U' spectral feature and 'zero field effect'. On the basis of them, the crystal field strength and the local symmetry around Gd3+ in the complex have been discussed.展开更多
基金National Natural Science Foundation of China (No. 29671026)Natural Science Foundation of Zhejiang Province (No. 296062)State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics (No. 971502).
文摘Nine Ln( Ⅲ ) complexes with a novel Schiff base derived from diglycolamine and benzoylacetone (BZDA) have been synthesized and characterized. They can be formulated as [Ln2(BZDA)3(NO3)3](NO3)3· nH2O(Ln=La, Pr, Nd, Sm, n = 4; Ln=Gd, Tb, Er, Yb, Y, n = l). Enamic form mechanism in this β-diketone Schiff base and its complexes were suggested and proved by IR, UV and NMR methods. The 13C spin-lattice relaxation time T1 and the ratios of r(ci-Ln)/r(cj-Ln) were measured by a 500 MHz NMR instrument for elucidating the formation of the stable sk-membered chelate ring structure in these complexes. The EPR spectrum of the Gd( Ⅲ ) complex exhibits the 'U' spectral feature and 'zero field effect'. On the basis of them, the crystal field strength and the local symmetry around Gd3+ in the complex have been discussed.
