Synthesis and Characterization of Oxozirconium(IV), Dioxomolybdenum(VI) and Dioxotungsten(VI) with Ciprofloxacin and Norfloxacin Complexes

The interaction of quinolone drugs, ciprofloxacin (CIPH) and norfloxacin (NORH), with zirconyl chloride octahydrate, sodium molybdate dihydrate and sodium tungstate dihydrate was investigated. Elemental analysis, FTIR spectral, electrical conductivity, magnetic susceptibility and UV Visible spectroscopy measurements have been used to characterize the isolated complexes. The results support the formation of two types of complexes of formula [ZrO(H2O)L2]3H2O and [MO2L2] where L = CIP and NOR; M = Mo and W. FTIR spectra of both types of complexes suggest that CIP and NOR act as deprotonated bidentate ligands through the ring carbonyl oxygen atom and one of the oxygen atom of carboxylic group

Syntheses and Characterization of Salts with the [Al(D)₄F₂]⁺ Cation (D = Pyridine or Water)

Our approach for preparation of <i>tetrakis-</i>(pyridine)-difluoro-aluminum chloride was successfully deployed for the synthesis of corresponding Br and I compounds, respectively. By reacting AlX₃·3Py (X = Cl, Br, I) with Me₃SiF in pyridine, two of the three halogens X were substituted by fluorine atoms forming the “aluminum mixed halide” complexes AlF₂X·4Py with the ionic solid-state structures [Al­(Py)₄F₂]­X. Whereas the ²⁷Al solid state NMR spectra of AlX₃·3Py (X = Cl, Br) confirmed the existence of the expected singular σ⁶λ³-Al centers in their structures, the corresponding spectrum of AlI₃·3Py does not contain any signal that belongs to a 6-fold coordinated Al atom. The elemental analysis data strongly support the 1:2-stoichiometry of the complex (AlI₃·2Py), which in accord to the ²⁷Al MAS NMR spectra possessed only one σ⁴λ³-Al side as in the ionic structure [Al­(Py)₂I₂]­I. AlBr₃·3Py was also transformed by pyridine into the ionic complex [Al­(Py)₄Br₂]­Br. The later was isolated from pyridine solutions, and its structure was determined by X-ray single crystal analysis. On the basis of our results, solvated [Al­(Py)_<i>n</i>X₂]⁺ cations are most probably the dominating species in pyridine solutions of AlX₃. Thus, only two Al–X covalent bonds underwent X/F- exchange and the halogen exchange reactions were terminated at “ [Al­(Py)₄F₂]⁺ stage”. The hydrolysis of [Al­(Py)₄F₂]Cl by very diluted hydrochloric acid in methanol proceeded smoothly under preservation of the Al–F bonds and displacement of pyridine by water. The formation of the stable helical <i>trans-</i>octahedron [Al­(H₂O)₄F₂]⁺ cation was confirmed by single-crystal XRD analysis. By reacting [Al­(Py)₄F₂]Cl with the <i>cyclo</i>-<i>n</i>-propyl-phosphonic acid anhydride [CH₃CH₂CH₂–PO₂]₃, an unexpected F-migration from Al- to P- atoms was observed