engleski

ESI MS/MS study of Fe(III) and Ga(III) complexes with aromatic hydrazones derived from nicotinic acid hydrazide

Aromatic hydrazones have been shown as promising iron-chelating agents [1]. Recent studies have shown that salicylidene acylhydrazide strongly binds gallium and that chelation of Ga(III) increase the stability of hydrazones against acid-induced hydrolysis 2. In this work three hydrazone derivatives, namely N’-(2-hydroxy-3- methoxyphenylmethylidene)-3-pyridine- carbohydrazide (1), N’-(2-hydroxy-4- methoxyphenylmethylidene)-3- pyridinecarbohydrazide (2) and N’-(2-hydroxy-5- methoxyphenylmethylidene)-3- pyridinecarbohydrazide (3), were prepared and their complexes with Fe(III) and Ga(III) ions in acidic methanol/water 1/1 media were analysed by ESI MS. Since aroylhydrazones can be involved in keto- enol tautomeric interconversion, they can act as neutral, monoanionic or dianionic ONO tridentate ligands [3]. Comprehensive MS/MS analyses were performed on singly and doubly charged ions of 1–3 complexes with Fe(III) and Ga(III), and fragmentation pathways were proposed. Hydrazones dominately coordinate as doubly deprotonated ONO ligands. The stability of ligands was increased upon complexation [4]. The results of MS analysis were compared with those obtained by spectrophotometric titrations.

Aromatic hydrazones ; Complexes ; Mass spectrometry

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