Abstract
To understand complexation behavior of the antibiotic chloramphenicol, we studied metal(II) coordination to chloramphenicol by various spectroscopic techniques. The crystal system, lattice parameters, unit cell, particle size, and volume were determined by X-ray diffraction data. The geometries of the complexes were optimized on the basis of molecular modeling. Spectroscopic data indicate deprotonation and coordination of the secondary alcoholic OH group with metal ions, but the amide group does not participate in coordination. The mass spectra explain the successive degradation of the molecular species in solution and justify the ML formulation. The crystal data are as follows: Zn complex I is triclinic, space group P1, a = 6.904155, b = 12.571030, c = 13.779020, α = 84.349950°, β = 97.198170°, γ = 68.494130°, V = 1090.30 Å 3; Cd complex II is triclinic, space group P1, a = 8.27650, b = 12.12506, c = 16.682035, α = 131.3720°, β = 117.57101°, γ = 62.100240°, V = 1349.59Å 3; Sn complex III is orthorhombic, space group Pmmm, a = 21.990940, b = 13.121410, c = 11.885110, α = β = γ = 90°, V = 3429.47 Å3 and Pb complex IV is triclinic, space group P1, a = 5.75102, b = 12.25601, c = 24.83562, α = 63.4777°, β = 79.9567°, γ = 52.3962°, V = 1228.92 Å3. Molecular structures of the complexes were optimized by MM2 calculations and supported tetrahedral arrangements around metal(II) ions.