不同温度下Cu(Ⅱ)—氨基酸水杨醛席夫碱二元配合物的稳定性

STABILITY OF BINARY COMPLEXES OF Cu(Ⅱ)-N- SALICYLIDENEAMINO ACID AT DIFFERENT TEMPERATURE

在 15± 0 .1℃ ,2 5± 0 .1℃ ,35± 0 .1℃ ,I =0 .1mol/LKNO3 条件下 ,应用 pH电位滴定法测定了α_氨基酸水杨醛席夫碱的酸离解常数和铜 (Ⅱ )_α_氨基酸水杨醛席夫碱二元配合物的稳定常数 .实验发现 ,在所有温度下 ,二元配合物的稳定性与配体碱性之间均存在良好的直线自由能关系 。

The dissociation constants of Schiff base derived from α-amino acid and salicylaldehyde and stability constants of Cu(Ⅱ)_N_salicylideneamino acid binary complexes were determined by means of pH method in the presence of 0.1 mol·dm -3 KNO 3 at 15±0.1 ℃, 25±0.1 ℃ and 35±0.1 ℃ respectively. The amino acid used were glycine, alanine, L_valine, L_leucine and L_phenylalanine. It was found that the linear free energy relationship(LFER) between the stability of binary complexes and the base strength of the ligand existed nicely at the same temperature, and the formation reaction of complexes was exothermal reaction.