化学学报 ›› 1999, Vol. 57 ›› Issue (9): 961-966. 上一篇    下一篇

研究论文

系列双核Ln(III)配合物的晶体结构和磁性

牛淑云;杨忠志;孙仁安;杨冰;杨光第;卜为民;曹金全;杨清传   

  1. 辽宁师范大学化学系.大连(116022);吉林大学化学系理论化学研究所.长春 (130023);北京大学化学系.北京(100871)
  • 发布日期:1999-09-15

Crystal structures and magnetism of the binuclear Ln(III) complexes

Niu Shuyun;Yang Zhongzhi;Sun Renan;Yang Bing;Yang Guangdi;Bu Weimin;Cao Jinquan;Yang Qingchuan   

  1. Liaoning Normal Univ., Dept of Chem.Dalian(116022);Jilin Univ, Dept Chem, Inst Theoret Chem.Changchun(130023);Beijing Univ., Dept. of Chem.Beijing(100871)
  • Published:1999-09-15

合成了分子式为[Ln~2(phen)~2L],phen=C~1~2H~8N~2[ALn=Nd,L=(CH~3COO)~4(ONO~2)~2,BLn=Sm,L=(C~6H~5COO)~6,CLn=Eu,L=(C~6H~5COO)~6]3种同双核配合物。用X射线四圆衍射仪测定了3种化合物的结构。在化合物A分子中,2个Nd(III)原子由4个CH~3COO^-基团桥联,以phen和ONO~2^-为端基,构成了一个具有C~2对称性的双核分子。配合物B和C具有完全相同的结构,它们是以4个苯甲酸根为桥,2个phen和2个C~6H~5COO^-为端基的中心对称双核分子,其中6个苯甲酸根的成键状态可分为3种状况。在3种化合物中,每个Ln均为9配位,呈不规则多面体。Ln-Ln距离,A为0.397nm,B和C均为0.405nm。测定了各配合物的变温磁化率,通过对磁性质研究,发现化合物A在低温下具有反铁磁物质行为,并由理论拟合,求得了磁参数g,J值。

关键词: 双核配合物, 晶体结构, 磁性, 四园衍射仪, 镧系元素, 钕化合物, 铕化合物, 钐化合物

Three binuclear Ln(III) complexes with formulas [Ln~2(phen)~2L], [phen=C~1~2H~8N~2, A Ln=Nd, L=(CH~3COO)~4(ONO~2); B Ln=Sm, L= (C~6H~5COO)~6; C Ln=Eu, L=(C~6H~5COO)~6] have been synthesized. Their molecular structures and crystal structures have been determined by X-ray diffraction analysis. In the complex A, two Nd(III) ions are bridged by four CH~3COO^- groups and coordinated to two phen and ONO~2^- groups, giving a binuclear Nd~2(phen)~2(ONO~2)~2(CH~3COO)~4 unit. This molecule possesses C~2 point group symmetry. The structures of the complexes B and C are completely same. They are centrosymmetric binuclear molecules with four benzoate bridges and two phen and two C~6H~5COO^- ligands. Every Ln atom is 9-coordinated in an irregular polyhedron. The distance of Ln-Ln is 0.397nm for complex A and 0.405nm for complexes B and C. Cryomagnetic investigations reveal a weak antiferromagnetic property only for the complex A.

Key words: DINUCLEAR COMPLEX, CRYSTAL STRUCTURE, MAGNETISM, FOUR- CIRCLE DIFFRACTOMETER, LANTHANON, NEODYMIUM COMPOUNDS, EUROPIUM COMPOUNDS, SAMARIUM COMPOUNDS

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