Antimycobacterial activity of mixed-ligand copper quinolone complexes

New mixed-ligand CuII, complexes: [Cu(cf)(phen)Cl)](BF4) · 4H2O (3), [Cu(cf)(bipy)(Cl)](BF4) · 2H2O (4) and [Cu(cf)(dafone)(Cl)](BF4) · 2H2O (5) (cf = ciprofloxacin, phen = 1,10-phenanthroline, bipy = 2,2′-bipyridine and dafone = 4,5-diazafluoren-9-one) have been isolated and characterized by elemental analyses, i.r., u.v.–vis. spectra, magnetic susceptibility and cyclic voltammetry. Complex (4) crystallizes in the monoclinic space group P21/n with a = 13.8919(13) A, b = 14.5718(13) A, c = 14.0725(13) A, β = 95.150(2)°, V=2837.2(5) A3. All complexes possess square-pyramidal geometry. The antimycobacterial activity of ciprofloxacin and complexes (3–5) has been evaluated against Mycobacterium smegmatis, which shows clear enhancement in the antitubercular activity upon copper complexation with N—N donors.