Synthesis and characterization of new addition compounds of bis(2-hydroxyaryloximato) nickel(II) with alpha-diimines - Crystal and molecular structure of [Ni(saox)(2)phen]center dot H2O

A series of new addition compounds of bis(2-hydroxyaryloximato) nickel(II), [Ni(ox)(2)], with an alpha-diimine (enR), under the general formula [Ni(ox )(2)enR], were synthesized and characterized. The TR and electronic excitat ion spectra indicate that the bidentate coordination mode of the ligands co nsists with the chromophore NiN4O2. The octahedral environment around nicke l(II) was confirmed by an X-ray structure analysis of [1,10-phenanthroline- bis(2-hydroxy-benzaldoximato)nickel(II)], [Ni(saox)(2)phen] . H2O. The equa torial plane, which encompasses the nickel atom, is formed by four nitrogen atoms, two coming from the phenanthroline molecule and two from the two mo lecules of the 2-hydroxybenzaldoxime (salicylaldoxime). In the apical posit ions lie the two deprotonated phenolic oxygen atoms of the two salicylaldox ime ligands. The thermal stability and decomposition mode were studied in n itrogen using the technique of thermogravimetry (TG/DTG). Mass spectrometry was also used, and possible fragmentation patterns are given and discussed . (C) 1999 Elsevier Science Ltd. All rights reserved.