Synthesis and Characterization of Two Novel Zinc(II) Complexes with Ciprofloxacin. Crystal Structure of [C17H19N3O3F]2 ⋅ [ZnCl4] ⋅ 2H2O

The complexation of ZnII ions with quinolone in aqueous solution depends mainly upon pH. To investigate the pH dependence of the complexation between ZnII and the quinolone derivative Ciprofloxacin (abbreviation cfH), UV-Vis spectroscopy was used. The crystal structure of the compound [C17H19N3O3F]2 ⋅ [ZnCl4] ⋅ 2H2O (compound I) was determined by X-ray diffraction, which showed the structure to be ionic, consisting of a tetrachlorozincate(II) dianion and two protonated, monocationic Ciprofloxacin molecules. Compound II ([Zn(cf)2] ⋅ 3H2O) was obtained as microcrystals from an aqueous solution of Ciprofloxacin hydrochloride and zine sulphate adjusted to pH = 8 by the addition of sodium hydroxide. Both complexes were characterized by elemental analysis, mass speetrometry, TG analysis and IR spectroscopy. From the analysis of these results we have proposed a probable mode of bonding for the complexation of ZnII to Ciprofloxacin in compound II

Search of low-dimensional magnetics on the basis of structural data: spin-1/2 antiferromagnetic zigzag chain compounds In2VO5, beta-Sr(VOAsO4)2,(NH4,K)2VOF4 and alpha-ZnV3O8

A new technique for searching low-dimensional compounds on the basis of structural data is presented. The sign and strength of all magnetic couplings at distances up to 12 A in five predicted new antiferromagnetic zigzag spin-1/2 chain compounds In2VO5, beta-Sr(VOAsO4)2, (NH4)2VOF4, K2VOF4 and alpha-ZnV3O8 were calculated. It was stated that in the compound In2VO5 zigzag spin chains are frustrated, since the ratio (J2/J1) of competing antiferromagnetic (AF) nearest- (J1) and AF next-to-nearest-neighbour (J2) couplings is equal to 1.68 that exceeds the Majumdar-Ghosh point by 1/2. In other compounds the zigzag spin chains are AF magnetically ordered single chains as value of ratios J2/J1 is close to zero. The interchain couplings were analyzed in detail.Comment: 14 pages, 6 figure, 1 table, minor change