METAL-COMPLEX DYES OF NICKEL WITH SCHIFF-BASES

Nickel complexes with Schiff bases 2-(2-pyridylmethyleneamino)phenol ( PMAP) and 2-(2-quinolylmethyleneamino)phenol (QMAP) were prepared and the composition of the crystalline complexes was determined by element al analysis, solubility, UV-Vis, IR and mass spectrometry. It was foun d that, for the Ni-PMAP complex, two ligands were bonded to one metal ion, giving a neutral complex with one molecule of water probably bond ed in the inner sphere of the complex. With QMAP, nickel forms cationi c complexes with a metal-to-ligand ratio of 2:2 and two molecules of a cetate as anions. The solution properties of Ni-QMAP were investigated at different pH. The chromophoric properties of the complex were enha nced with increase in pH, while stability decreased with time. The app lication of QMAP as a spectrophotometric reagent for the determination of small amounts of nickel was investigated Adherence to Beer's law w as observed from 0.00 to 5.00 mu g/ml at pH 8, the most appropriate pH in respect to sensitivity and acceptable time stability of the comple xes. Dyeing properties of both complexes were investigated on polyamid e 66 and the influence of the addition of another phenyl ring to the l igand molecule on the dyeing properties of the complex is discussed.