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在用直接反应法合成稀土金属醇盐的反应中,传统上一直以I2或Hg2+系列盐(如HgCl2,Hg(C2H3O2)2和HgI2等)或其混合物做催化剂.对某些金属合成反应会存在反应速率低、产率低的问题.通过以无水AlCl3做催化剂、金属钇薄片和异丙醇为原料,加热回流直接反应,成功地合成了异丙醇钇.反应中放出大量H2和红外吸收光谱分析结果证明产物确为异丙醇钇.实验证明以无水AlCl3做催化剂可以大大提高反应速率和产率.实验和理论分析揭示了无水AlCl3的催化机理:无水AlCl3与异丙醇作用生成了HCl和可表示为AlCl2(OPri).2AlCl3.PriOH的中间产物,使整个体系的酸性提高,从而加速了反应的进行.AlCl3催化机理完全不同于I2和Hg2+系列盐类,这里H+为氧化剂,起重要作用.使用无水AlCl3替代传统催化剂可以解决I2做催化剂对某些反应的效率低下问题,或Hg2+系列盐类的毒性问题.
In the synthesis of rare earth metal alkoxides by direct reaction, traditionally, I2 or Hg2 + salts (such as HgCl2, Hg (C2H3O2) 2 and HgI2), or mixtures thereof, have traditionally been used as catalysts. For some metal synthesis reactions Low reaction rate and low yield.The yttrium isopropoxide was successfully synthesized by anhydrous AlCl3 as catalyst, metal yttrium flake and isopropanol as raw materials and direct reaction by heating and refluxing.A lot of H2 and infrared absorption were released during the reaction The results of spectroscopic analysis show that the product is indeed yttrium isopropoxide.The experimental results show that the reaction rate and yield can be greatly improved by using anhydrous AlCl3 as catalyst.Experimental and theoretical analysis reveal the catalytic mechanism of anhydrous AlCl3: anhydrous AlCl3 and isopropanol The formation of HCl and the intermediate product that can be expressed as AlCl2 (OPri) .2AlCl3.PriOH, accelerates the overall acidity of the system and accelerates the reaction. The mechanism of AlCl3 catalysis is completely different from that of I2 and Hg2 + salts where H + is the oxidant , Plays an important role.Using anhydrous AlCl3 instead of the traditional catalyst can solve the problem of I2 as a catalyst for some reactions inefficiency, or Hg2 + series of salts toxicity problems.