摘要
用铜离子选择电极测定五种α-氨基酸(对氟苯丙氨酸、丝氨酸、缬氨酸、丙氨酸及α-氨基异丁酸)的铜(Ⅱ)配合物在25.0±0.1、35.0±0.1和45.0±0.1℃,μ=0.16mol L^(-1)KNO_3时于水中及30%(V/V)和50%(V/V)的乙醇-水中的稳定常数.用pH电位法测定了各配体在混合溶剂中的离解常数.实验表明用铜离子选择电极研究上述配合物在混合溶剂中的线性自由能、线性焓和线性熵关系,得到了较好的结果.
The stability constants of coordination compounds formed from some α-aminoacids(αA) DL-P-Fluoro phenylalanine, DL-Serine, DL-Valine, DL-Alanine and α-amino-isobutyric acid with Cu(Ⅱ) were measured by Ion-Selective Electrode at 25±0. 1, 35±0. 1 and 45±0. 1℃ in water, 30% ethanol and 50% ethanol solution inthe presence of 0. 16mol·dm^(-3) KNO_3. The order of stability of the Cu(Ⅱ)-αAcoordination compounds is in 50% ethanol solution>in 30% ethanol solution>in waterat 35±0. 1℃. Linear relationships not only existed between the stability of Cu(Ⅱ)-αA coordi-nation compouds and the base strength of ligands but also existed between the form-ation enthalpy of coordination compounds and the protonation enthalpy of the ligands,and between the formation entropy of coordination compounds and the protonationentropy of the ligands as well. 25-45℃ △H_(ML)~?=0. 2246△H_L~?-6. 217 r=0.9986 25℃ △S_(ML)~?=-0. 1929△S_L~?+109.1 r=-0.9461
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1990年第1期51-56,共6页
Acta Physico-Chimica Sinica
