稀土丙酸盐的红外光谱研究

本文研究了La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y十三种稀土丙酸盐的FT-IR光谱, 对1800-100cm^-^1的主要红外吸收谱带进行了归属, 指认316-349cm^-^1的强吸收带为Ln-O键的伸缩振动带. 稀土丙酸盐红外光谱表明存在两种不同的羧基配位形式. 从La到Tm以及Y等十一种丙酸配合物的配位羧基具有对称的螯合双齿形式, 而对稀土Yb和Lu, 与中心离子配位的三个羧基中, 至少有一个羧基具有螯合桥式三齿配位形式. 结果还表明稀土丙酸盐Ln-O键基本上是离子键.

Infrared spectra of some rare earth propionates

Fourier transform IR spectra of the propionates of La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y were studied. The principal IR absorption bands were assigned for 100-1800 cm-1. The strong absorption bands near 316-349 cm-1 were believed to be Ln-O stretching bands. Mid-IR spectra of rare earth propionates can be divided into 2 types, indicating that there are 2 different carboxylate coordinate forms. For 11 of the 13 rare earth propionates (except Yb, Lu), the carboxylate coordination had the chelating bidentate form, whereas at least, 1 of the 3 carboxylate groups had the form of chelation-bridging tridentate for Yb and Lu propionates, i.e. 1 of the carboxyl O was shared between 2 adjacent metal ions. The Ln-O bond of rare earth propionate is principally ionic.