Studies on ionic chelates of hafnocene with kojic acid and maltol

Abstract

Ionic chelates of hafnocene with kojic acid (<i>I</i>) and maltol (<i>II</i>) of the type [(η⁵- C₅H₅)₂ HfL¹]⁺ X¯ (<i>Ia</i>) and [(η⁵- C₅H₅)₂ HfL²]⁺ X¯ (<i>IIa</i>)<i> </i>[X = CuCl₃, ZnCl₃, CdCl₃, HgCl₃, C₆H₅NHNHCS₂; HL¹ = kojic acid, HL² = maltol] have been

synthesized and characterised by IR, UV, ¹H NMR and ¹³C NMR spectral studies. Conductance measurements reveal that the compounds are 1:1 e lectrolytes. Fluorescence studies have been carried out for the complexes containing mercury in the anionic moiety and relevant photochemical parameters have been elucidated. Thermodynamic parameters have been

calculated using thermogravimetric and differential thermal analytical curves and their variations have been correlated with some structural parameters of the complexes. Activity of representative complexes <i>vs. E.coli, S.typhi, P.aeruginosa,</i> <i>Z.mobilis </i>bacterial strains and activity of all the complexes <i>vs. A. awamori </i>and <i>A. niger </i>fun gal strains have been studied and the general order of activity has been deduced.