Cyclam-based iron(iii) and copper(ii) complexes: synthesis, characterization and application as antifungal agents†
Abstract
New cyclam-based complexes of formulae [{H2(4-CF3PhCH2)2Cyclam}FeCl2]Cl and [{H2(4-CF3PhCH2)2Cyclam}Cu](CH3COO)2·2H2O were synthesized, in very high yields, by the reaction of H2(4-CF3PhCH2)2Cyclam with the corresponding metal salts in methanol. [{H2(4-CF3PhCH2)2Cyclam}FeCl2]Cl was also prepared, quantitatively, in the solid state by mechanochemistry. The Mössbauer spectra of [{H2(4-CF3PhCH2)2Cyclam}FeCl2]Cl show that the high-spin cis complex is the major product of both reactions. The EPR data of [{H2(4-CF3PhCH2)2Cyclam}Cu](CH3COO)2·2H2O are consistent with two distinct Cu2+ species, whose solid state molecular structures were determined by single crystal X-ray diffraction and correspond to complexes displaying octahedral and square–pyramidal geometries. The screening of the antifungal activity of both metal complexes revealed the higher activity of [{H2(4-CF3PhCH2)2Cyclam}FeCl2]Cl to inhibit the growth of unicellular and multicellular fungal species with described pathogenic potential.