Chelating Properties of New Series of Heterocyclic hydrazones. X-ray Crystallography and Mass Spectrometry of Their Metal Complexes

The chelating properties of a new series of α-N-heterocyclichydrazones (heterocycle=substituted quinoline, benzothiazole, phthalazine) have been studied. Nickel complexes have been synthesized and structurally characterized in the gas phase by mass spectrometry and tandem mass spectrometry, and in the solid state by x-ray crystallography. Each ligand (LH) acts as tridentate and it undergoes a deprotonation in the complex formation. The complexes are neutral species and they can be formulated as [ML2]. The crystal structure of bis[N-(2-benzothiazolyl)-N′-(methlymethoxycarbonyl)hydrazine]nickel(II) ×0.5 H2O has been determined. The metal shows a pseudo-octahedral polyhedron and it is coordinated to two nitrogen and to oxygen atoms in the equatorial plane, and to two hydrazone nitrogen atoms in the axial positions.