In this study, novel 1,3-substituted phenyl-5-phenylformazans were synthesized with -NO2, -Cl, -Br, -CH3, -OCH3 groups in the o-, m-, and p-position of the 1-phenyl ring and -NO2, -OCH3 groups in the m- and p-position of the 3-phenyl ring. Their structures were elucidated by elemental analysis and GC-mass and their spectral behaviors were investigated with H-1 NMR, C-13 NMR, IR, UV-vis spectra. The absorption characteristics of the compounds were examined by UV-vis spectra. There was a shift in lambda(max) whose amount was dependent upon the type and position of the substituent on the ring. A linear correlation was obtained between this substituent effect and Hammett substituent coefficients. (c) 2006 Elsevier Ltd. All rights reserved.