本研究系統性的探討配體（ortho-氨基苯酚和3,4-二羥基苯甲酸）與各種二價金屬離子（Cu2+, Be2+, Zn2+, Ni2+, Co2+, 和Mn2+）在恆溫37℃ 和 離子強度0.15 mol.dm-3 NaCl下之螯合作用。研究利用電位滴定和分光光度法，配合Hyperquad2008和HySS軟體以探討在二元和三元系統中金屬與配體錯合物之形成及穩定性。
兩種配體皆擁有以官能團氨基（-NH2），羟基（-OH）和羧基（-COOH）形式存在的潛在接合位置。系統中若含3,4-二羥基苯甲酸（D配体）會比含ortho-氨基苯酚（A配体）形成更穩定的金属錯合物。在金屬與配體在二元和三元的系統中形成錯合物時，其穩定性按以下順序：Cu2+, Be2+, Zn2+, Ni2+, Co2+, Mn2+ 遞減。，其中有強烈到弱的協調。本研究也計算ΔlogK以研究三元錯合物相對於對應的二元錯合物之穩定性，結果發現ΔlogK 為負值，是以形成二元錯合物（MA或MD）比形成三元錯合物（MAD）更容易。另外也計算參數logX用以度量一莫耳二元錯合物MA2和一莫耳二元錯合物MD2形成兩莫耳MAD之傾向。

Chelations of ligand (ortho-aminophenol and 3,4-dihydroxybenzoic acid) with various divalent metal ions (Cu2+, Be2+, Zn2+, Ni2+, Co2+ and Mn2+) at constant temperature 37°C and ionic strength 0.15 mol.dm-3 NaCl were systematically investigated. The studies were carried out by employing potentiometric and spectrophotometry method, along with Hyperquad2008 and HySS software, to investigate the formation and stability of metal-ligand complex formed in binary and ternary system.
Both ligands possess potential coordinating sites which exist as amino (-NH2), hydroxyl (-OH) and carboxyl (-COOH) functional groups. The system that contains 3,4-dihydroxybenzoic acid (D) is more stable than that contains ortho-aminophenol (A). In the following order: Cu2+, Be2+, Zn2+, Ni2+, Co2+, Mn2+, metal ion that occupies front position will form complex in binary and ternary systems with higher stability than that of metal ion in the rear position. To investigate the stability of ternary complexes relative to their corresponding binary complexes, calculation of log K was done and negative values were obtained. Thus the formation of binary complex (MA or MD) is more favorable than ternary complex (MAD). Another parameter, log X, was also calculated to measure the tendency of one mole each of the binary complexes MA2 and MD2 to form two moles of MAD.

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