摘要
在25±0.1℃,Ⅰ=0.1mol·dm^(-3)KNO_3条件下,在80％(V/V)DMSOH_2O混合溶剂中,应用pH电位法测定了水杨醛缩氨基硫脲(缩写H_2L,记为A配体),α-氨基酸(缩写α-AA,记为B配体)的酸性离解常数,铜(Ⅱ)—水杨醛缩氨基硫脲,铜(Ⅱ)-α-氨基酸二元配合物和铜(Ⅱ)—水杨醛缩氨基硫脲-α-氨基酸三元配合物的稳定常数。所用的α-氨基酸有甘氨酸,缬氨酸,脯氨酸,丝氨酸和苯丙氨酸。实现发现在logβ_102与PK_2~B,logβ_111与PK_2~B及logβ_111与logβ_102三对参数之间均存在良好的直线自由能关系。用△logK_M和△logβ_111描述了三元配合物相对于二元母体配合物的稳定性。应用溶剂的性质,配体间的疏水作用和堆积作用讨论了配合物的稳定性。
The dissociation constants of salicyaldehyde thiosemicarbazone (H_2L) and amino acid (α-AA) and stability constants of Cu(Ⅱ)-H_2L, Cu(Ⅱ) -α-AA binary complexes and Cu(Ⅱ)-H_2L-α-AA ternary complexes in 80% (V/V) DMSO-H_2O mixed solvens, at 25±0.1℃ in the presence of 0.1tool. dm^(-3)KNO_3 have been determined by pH method. The α-amino acid used were glycine, L-valine, L-proline, L-serine and DL-phenylalanine. These results show that the linear free energy relationships exist nicely between the following parameter pairs: logβ_(102) and PK_2~B, logβ_(111)and PK_2~B and logβ_(111) and logβ_(102), The factors contributing to the stability of binary and .ternary complexes are discussed,
出处
《曲阜师范大学学报（自然科学版）》
CAS
1993年第4期52-56,共5页
Journal of Qufu Normal University(Natural Science)
关键词
稳定常数
席夫碱
络合物
配体
碱性
stability constants
linear free energy relationships
shill base
a-amino acid
