کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
177934 459007 2006 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Binary and ternary metal complexes of Congo red with amino acids
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Binary and ternary metal complexes of Congo red with amino acids
چکیده انگلیسی

The stability constants of the 1:1 binary complexes of Ag+, Ni2+, Co2+, Y3+ metal ions with glutamic acid (Glu), leucine (Leu) and Congo red (CR) and their 1:1:1 ternary complex and the protonation constants of the ligands were determined potentiometrically at a constant ionic strength of I = 0.10 mol dm−3 (NaClO4) in aqueous solutions at 15.0, 25.0 and 35 °C. The thermodynamic parameters ΔGo, ΔHo and ΔSo were reported for the complex formation reactions. The enthalpy changes of all complexation are found to be negative but entropy changes positive. The driving forces for the formation of Ag–CR, Ni–CR, Co–CR are the enthalpy decreases. But the driving force for Y–CR is the entropy decreases. The driving force of Ni–Glu, Co–Glu, Ni–Leu and Co–Leu systems are about equally enthalpy decrease and entropy increase while Ag–Glu and Ag–Leu complexation are enthalpy stabilized. But, the driving force of Y–Glu and Y–Leu systems are the entropy increase. For formed ternary complexes the reactions are all enthalpy-driven.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Dyes and Pigments - Volume 70, Issue 2, 2006, Pages 136–142
نویسندگان
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