Synthesis, spectral, fluorescence, thermal and biological studies on ionic hafnocene pyrimidine complexes

Ionic chelates of hafnocene with uracil (HL1) (A) and 5-fluorouracil (HL2) (B) of the type [(η5- C5H5)2HfL1]+X− (C) and [(η5- C5H5)2HfL2]+X− (D) (X = CuCl3, ZnCl3, CdCl3, HgCl3, PhNHNHCS2) have been prepared and characterised by conductivity measurements and by i.r., electronic, 1H-n.m.r. and 13C-n.m.r. spectra. Fluorescence studies of the complexes containing Hg in the anionic moiety, and relevant photochemical parameters, have been elucidated. Thermodynamic parameters have been calculated using thermogravimetric (t.g.) and differential thermal analytical (d.t.a.) curves, and their variations have been correlated with some structural parameters of the complexes. The ligands, as well as their hafnium(IV) complexes, exhibit appreciable antibacterial and antifungal activity against E. coli, S. typhi, P. aeruginosa and Z. mobilis bacterial strains, and versusA. awamori and A. niger fungal strains, respectively.