XAFS STUDY OF METAL-FORMAZAN COMPOUNDS

XAFS studies have been performed to clarify the relationship between t he corresponding pH, color and the structural changes of metal(Cu. Ni) -(o-PHF)n -(2-hydroxyphenyl)-3-phenyl-5-(2-pyridyl)formazan; Fig. 1] c omplex. The structural change of the Cu(o-PHF) complex has been attrib uted to the change of bonding mode of the -OH group in the formazan li gand to the metal. The Ni(o-PHF)n complex has been proved to from diff erent structures, 6-coordinated 1:2 complex and 4-coordinated 1:1 comp lex in acid and alkaline media, respectively.