THE SYNTHESİS OF SOME BIS-SUBSTITUTED FORMAZANS AND THE INVESTIGATION OF THE EFFECT OF SUBSTITUENT UPON THEIR UV- VIS. ABSORPTION X.lnax VALUES

In this study l,4-bis-[3,3’-phenyl-5,5’-(2-carboxyphenyl)-formaz-l-yl]-benzene-2-sulphonic acid (2,CSPF) and its derivatives with OH groups at the o-, m- and p- positions of 3-phenyl ring were synthesized. The structures of the formazans thus obtained were elucidated by elemental analysis, MASS spectroscopy, IR, 'H-NMR and UV-Vis spectra. Also UV-Visible K™* values were investigated according to substituent effect. The Xmax values were observed to shift towards shorter wave lengths by 130 nm in CSPF relation to 1,3,5-triphenylformazan (TPF) due to the fact that the structure of CSPF contained electron withdrawing -COOH and -SO3H groups (hypsochromic effect). The addition of-OH group to 3-phenyl ring of CSPF, was observed a small bathochromic effect in accordance to the electron donating effect of -OH group.