N-Pyridoxylidenehydrazine-N', N'-diacetic Acid. III. Formation of Metal Chelates in Solution

• Published in: Chemical & pharmaceutical bulletin Vol. 35; no. 12; pp. 4695 - 4699
• Main Authors: MATSUSHIMA, YOSHIKAZU, NAGATA, YOSHIKO, TAMANO, YUKO, SUGATA, SETSURO, FUJIE, TADAO, KARUBE, YOSHIHARU, KONO, AKIRA
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 1987; Maruzen; Japan Science and Technology Agency
• Subjects: absorption spectrum; Chemistry; Coordination compounds; Cu (II); Exact sciences and technology; hydrazine; hydrazone; iminodiacetic acid; Inorganic chemistry and origins of life; metal chelate; methanol; N-pyridoxylidene-N'-methylhydrazine; N-pyridoxylidenehydrazine-N', N'-diacetic acid; Preparations and properties; pyridoxal; Cadmium II Complexes; Divalent metal Complexes; Cobalt «II» Complexes; Nitrogen heterocycle; Copper «II» Complexes; Complexone; Organic ligand; Transition metal Complexes; Nickel «II» Complexes; Lanthanum «III» Complexes; Trivalent metal Complexes; Organic solution; Six membered ring; Preparation; Chemical composition
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.35.4695

Metal chelate formation of N-pyridoxylidenehydrazine-N ', N '-diacetic acid (1) and related hydrazines in solution was studied by means of absorption spectroscopy. Compound 1 and N-pyridoxylidene-N'-methylhydrazine (2) in methanol formed Cu (II) chelates of the same spectral character, which indicated the chelation of the phenolate oxygen and the hydrazine nitrogen atoms to Cu (II). The compositions of the chelates were 1 : 1 for 1 and 1 : 2 for 2, indicating that 1 acts as a tri- or tetradentate ligand. N- (3-Hydroxy-4-pyridylmethylene) hydrazine-N', N'-diacetic acid formed a Cu (II) chelate similar to that of 1 but N-pyridoxylidene-N', N'-dimethylhydrazine and N-pyridoxylidene-N', N'-diphenylhydrazine did not form chelates under similar conditions. Addition of an equimolar or excess amount of Co (II), Ni (II), Zn (II), Cd (II) or La (III) salt to 1 in methanol gave rise to absorption assignable to the chelate of 1, whereas 2 did not form metal chelates under the same conditions. It was concluded that the iminodiacetic acid moiety of 1 coordinated to the metal ions and enhanced the stability constant of the metal chelates.