The synthesis and spectral properties of 1,3-substituted phenyl-5-phenylformazans and their Ni(II) complexes

Novel, 1:2 Ni(II) complexes of 1,3-substituted phenyl-5-phenylformazans were synthesized. The formazans contained –NO2, –Cl, –Br, –CH3 –OCH3 groups at the o-, m-, p-positions of the 1-phenyl ring and –NO2 and –OCH3 groups at the m- and p-positions of the 3-phenyl ring. Their structures were identified by elemental analyses, FTIR, 1H NMR, 13C NMR, UV–vis and GC–mass spectra. UV–vis spectra indicated that their λmax was shifted to an extent that depended upon the type and position of the substituent on the ring. A linear correlation was obtained between Hammett substituent coefficients and λmax values.