New Polymorph Form of Dexamethasone Acetate.

A new monohydrated polymorph of dexamethasone acetate was crystallized and its crystal structure characterized. The different analytical techniques used for describing its structural and vibrational properties were: single crystal and polycrystal X-ray diffraction, solid state nuclear magnetic resonance, infrared spectroscopy. A Hirshfeld surface analysis was carried out through self-arrangement cemented by H-bonds observed in this new polymorph.

cis-Bis{(E)-2-[(2-fluoro-phen-yl)imino-meth-yl]phenolato-κ(2) N,O}bis-(pyridine-κN)nickel(II).

The structure of the title compound, [Ni(C13H9FNO)2(C5H5N)2], consists of an Ni(II) atom on a crystallographic center of symmetry, octa-hedrally bonded through both the N and O atoms to two 2-[(2-fluoro-phen-yl)imino-meth-yl]phenolate (L) ligands, as well as two pyridine ligands. The F atoms of L are disordered over two positions related by a 180° rotation of the fluoro-phenyl group around its external C-N bond.

Novel zinc(II) and copper(II) complexes of a Mannich base derived from lawsone: Synthesis, single crystal X-ray analysis, ab initio density functional theory calculations and vibrational analysis.

Zinc(II) and copper(II) complexes of a tridentate Mannich base L1 derived from 2-hydroxy-1,4-naphthoquinone, pyridinecarboxyaldehyde and 2-aminomethylpyridine, [ZnL1Cl(2)]·H(2)O 1 and [CuL1Cl(2)]·2H(2)O 2, have been synthesized and fully characterized. The structure of complex 1 has been elucidated by a single crystal X-ray diffraction study: the zinc atom is pentacoordinate and the coordination geometry is a distorted square base pyramid, with a geometric structural parameter τ equal to 0.149.

An iron-based cytosolic catalase and superoxide dismutase mimic complex.

The development of metallodrugs with antioxidant activities is of importance as a way to protect organisms exposed to stressful conditions. Although iron chemistry in the presence of H(2)O(2) is usually associated with pro-oxidant activity, mainly via the Fenton reaction, we found that the mononuclear compound [Fe(HPClNOL)Cl(2)]NO(3) (1; C(15)H(18)Cl(3)FeN(4)O(4), a = 8.7751(3) A, b = 9.

trans-Bis[3-(2-fluorophenyl)-1-(4-nitrophenyl)triazenido-kappaN3]bis(pyridine-kappaN)palladium(II).

In the title complex, [Pd(C(12)H(8)FN(4)O(2))(2)(C(5)H(5)N)(2)] or trans-[Pd(FC(6)H(4)N=N-NC(6)H(4)NO(2))(C(5)H(5)N)(2)], the Pd atom lies on a centre of inversion in space group P-1. The coordination geometry about the Pd(2+) ion is square planar, with two deprotonated 3-(2-fluorophenyl)-1-(4-nitrophenyl)triazenide ions, FC(6)H(4)N=N-NC(6)H(4)NO(2)(-), acting as monodentate ligands (two-electron donors), while two neutral pyridine molecules complete the metal coordination sphere. The whole triazenide ligand is not planar, with the largest interplanar angle being 16.