Copper(II) complexes of the fluoroquinolone antimicrobial ciproffoxacin. Synthesis, X-ray structural characterization, and potentiometric study

Department of Chemistry, University of Queensland, Brisbane, Australia.
Journal of Inorganic Biochemistry (Impact Factor: 3.27). 05/1996; 62(1):1-16. DOI: 10.1016/0162-0134(95)00082-8
Source: PubMed

ABSTRACT Reaction of the fluoroquinolone antimicrobial ciprofloxacin with copper(II) nitrate in the presence of 2,2'-bipyridine resulted in the isolation of the complex [Cu(cip)(bipy) (Cl)0.7(NO3)0.3] (NO3).2H2O. Reaction of an aqueous solution of ciprofloxacin.HCl and NaCl with CuCl2 at pH 5.0 resulted in the isolation of [Cu(cip)2]Cl2.11H2O. The complex [Cu(cip) (bipy)(Cl)0.7(NO3)0.3] (NO3).2H2O crystallizes in the monoclinic space group P2(1)/n, with a = 13.955(8), b = 14.280(8), c = 14.192(6) A, beta = 93.10(4) degrees, Z = 4 with R = 0.046. The selective broadening of resonances in the 13C NMR spectrum of ciprofloxacin by the addition of Cu2+(aq) was employed to probe metal ion binding sites in the ligand. The protonation constants of norfloxacin and ciprofloxacin, and the formation constants with copper(II), were determined by potentiometric titrations at 25 degrees C. The additions of ciprofloxacin to metal to form ML and ML2 complexes exhibit stepwise formation constants of log K1 6.2(1) and log K2 11.1(3), respectively.

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    • "Me(CIP ± ) 2+ , Me(CIP ± ) 2 2+ , and Me(CIP − ·CIP ± ) + (Turel and Bukovec 1996; Wallis et al. 1996 "
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    • "The solid formed was filtrated, washed with pre-cooling deionized water, and finally lyophilized. CIP(Cu)$ÂH 2 O and (CIP) 2 Cd$ÂH 2 O were prepared according to the procedures reported by Wallis et al. (1996) and López-Gresa et al. (2002), respectively. In brief, CIP was dissolved in deionized water and metallic chloride was added. "
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