Metal ions-purine interactions: Dichloro-gold(III) complexes of some theophylline derivatives

摘要

Complexes with the general formula AuLCl2, whereLare the deprotonated forms of theophylline, 1,3,8-trimetylxanthine, 8-ethyl-theophylline, 8-isopropyl-theophylline and 8-pentyl-theophylline, have been synthesized and characterized by spectral (IR and1H-NMR) and thermal methods (TG and DSC). Experimental data suggest that all of them present a polymeric structure, in which the corresponding theophylline derivative acts as a monoanion, bonding to contiguous Au(III) ions through both imidazole nitrogen atoms. The structure of the monomer seems be square-planar, with the chlorine atoms linked to metal ion intranspositions.