Synthesis, characterisation, crystal structure and biological activity of metal(II) complexes with theophylline

Three metal complexes with empirical formulae [Mn(theop) 2 (H 2 O) 4 ] (1), [Co(theop) 2 (H 2 O) 4 ] (2), [Ni(theop) 2 (H 2 O) 4 ] (3), (where: theop = theophylline) were synthesized and characterized by elemental analysis, FTIR- spectroscopy and thermal decomposition techniques. Their crystal structures were determined by single crystal Xray diffraction analysis. Complexes are isomorphous and crystallise in the monocyclic space group P 21/ c . Their thermal behavior was studied by TGA methods under non-isothermal condition in air. Upon heating all compounds decompose progressively to metal oxides, which are the final products of pyrolysis. Furthermore, antimicrobial and antioxidant activity of the complexes was examined.