稀土金属醇盐的合成研究

PREPARATION OF RARE EARTH ALKOXIDES

用无水稀土乙酸盐 (乙酸镧、乙酸镨、乙酸钕、乙酸钐 )、金属钙粒与低碳醇 (甲醇、乙醇、异丙醇 )在芳香族类溶剂体系中回流加热反应 ,合成了稀土金属 (La ,Pr,Nd ,Sm)醇盐。各样品的红外光谱中均出现烷氧基与稀土元素键合的C -O -Re(Re为稀土离子 )键的特征吸收峰 ,稀土甲醇盐、稀土乙醇盐和稀土异丙醇盐的特征吸收峰分别位于 1 0 35 ,1 0 5 0cm- 1 和 1 1 6 0cm- 1 与 1 1 30cm- 1 左右。样品的紫外可见光谱也均出现了 3价稀土离子的特征吸收峰 ,证实样品为稀土醇盐。醇盐产率随低碳醇碳原子数的增加呈降低的趋势 ,即稀土甲醇盐 >乙醇盐 >异丙醇盐。醇盐产率随反应时间增加而逐渐增大 ,5～ 6h醇盐产率达到恒定。甲醇钐回流加热反应 6h的产率可达 84%。

The rare earth (La, Pr, Nd, Sm) alkoxides (methoxide, ethoxide and isopropoxide) were synthesized by a new method using alkaline earth metal calcium, lower alcohols (CH3OH, C2H5OH, C3H7OH) and anhydrous rare earth acetates as raw materials, and aromatic solvent as reaction medium. IR spectra results show that there appear the characteristic absorption peaks of the bond C-O-Re (Re: rare earth ions) of rare earth methoxides, rare earth ethoxides and rare earth isopropoxides at the wavelengths of 1035, 1050 cm-1, and 1160, 1130 cm-1 respectively. The characteristic absorption peak of rare earth ions in the UV-Vis spectra further confirms that the samples are rare earth alkoxides. The yield of rare earth alkoxides increases gradually with the increase of reaction time, and is stable in 5-6 h. The yield of samarium methoxide can reach to 84% after refluxed for 6 h by heating.