The solid complex of zinc L threonate has been prepared from the reaction mixture of L ascorbic acid, calcium carbonate and hydrogen peroxide in water at 0～3 ℃. It is purified by methyl alcohol extraction under redu...The solid complex of zinc L threonate has been prepared from the reaction mixture of L ascorbic acid, calcium carbonate and hydrogen peroxide in water at 0～3 ℃. It is purified by methyl alcohol extraction under reduced pressure. The composition of the complex is determined by chemical and elemental analyses and its formula fits Zn(C 4H 7O 5) 2. The purity of the complex is 99 60% by HPLC. The IR spectra indicate that Zn 2+ in the complex coordinates to oxygen atom of the carbonyl group and oxygen atom of the carboxyl group, while the proton of the carboxyl group is dissociated. It is assumed that the coordination number of Zn 2+ is 4. The TG DTG results show that the intermediate and final products of the thermal decomposition of the complex are Zn(CH 3COO) 2 and ZnO, respectively.展开更多
文摘The solid complex of zinc L threonate has been prepared from the reaction mixture of L ascorbic acid, calcium carbonate and hydrogen peroxide in water at 0～3 ℃. It is purified by methyl alcohol extraction under reduced pressure. The composition of the complex is determined by chemical and elemental analyses and its formula fits Zn(C 4H 7O 5) 2. The purity of the complex is 99 60% by HPLC. The IR spectra indicate that Zn 2+ in the complex coordinates to oxygen atom of the carbonyl group and oxygen atom of the carboxyl group, while the proton of the carboxyl group is dissociated. It is assumed that the coordination number of Zn 2+ is 4. The TG DTG results show that the intermediate and final products of the thermal decomposition of the complex are Zn(CH 3COO) 2 and ZnO, respectively.
