对新合成的钬-苯甲酸-联吡啶三元配合物进行了拉曼光谱分析,对配合物的振动频率作了归属,初步讨论了配体与镧系金属钬的配位方式。结果发现,在拉曼光谱中,配合物苯甲酸钬-联吡啶的羧基的反对称和对称伸缩振动的波数差Δν(νas-νs)为126 cm-1,小于其相应钠盐的波数差Δν(νas-νs)(150 cm-1)。依照红外光谱的配位规律,其配位方式应为桥式、螯合桥式三齿或螯合双齿。晶体结构测试结果表明,钬与苯甲酸六个氧原子配位方式为:两个螯合双齿和四个桥联双齿,所以拉曼光谱在表征羧酸根与金属配位方式的规律与红外光谱配位规律一致。
The newly synthesized ternary complex holmium(III) benzoate 2,2′-bipyridine,[Ho(BA)3bipy]2,was characterized by infrared and Raman spectra.The coordination modes of lanthanide metal holmium with the ligands were discussed initially by attributing vibration frequencies of the complexes.It was found that in the Raman spectra Δν(COO-)(126 cm-1) of asymmetric and symmetric vibrations of the COO-group in the complex was less than that in the sodium salt of benzoic acid(150 cm-1).In accordance with coordination rule of infrared spectra,the carboxylate groups coordinated to metal holmium might present three kinds of coordination modes: chelating bidentate,bridging bidentate or bridging-chelating tridentate.The results of the crystal structure showed that the carboxyl groups exhibited two kinds of coordination modes: chelating bidentate and bridging bidentate.Therefore,the coordination rule of carboxylate group with holmium analyzed by Raman spectra and by infrared spectra was consistent.