Structural and theoretical studies of amantadinium fenamates.

Two new crystals of amantadinium salts were obtained from fenamic and tolfenamic acid. The salt of fenamic acid is a model compound for interaction analysis, while amantadinium tolfenamate is a composition of a drug used in the treatment of symptoms of Parkinsonism and as a nonsteroidal anti-inflammatory drug. The crystal structures were studied and a theoretical analysis of the hydrogen bonds and weak interactions was carried out using quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) methods.

Crystal Structure and Chemical Bonds in [Cu(Tolf)(MeOH)]∙2MeOH.

A new coordination compound of copper(II) with a tolfenamate ligand of the paddle-wheel-like structure [Cu(Tolf)(MeOH)]∙2MeOH was obtained and structurally characterized. Chemical bonds of Cu(II)∙∙∙Cu(II) and Cu(II)-O were theoretically analyzed and compared with the results for selected similar structures from the CSD database. QTAIM analysis showed that the Cu(II)∙∙∙Cu(II) interaction has a strength comparable to a hydrogen bond, as indicated by the electron density at a critical point.

The Crystal Structure and Intermolecular Interactions in Fenamic Acids-Acridine Complexes.

In order to improve pharmaceutical properties of drugs, complexes are synthesized as combinations with other chemical substances. The complexes of fenamic acid and its derivatives, such as mefenamic-, tolfenamic- and flufenamic acid, with acridine were obtained and the X-ray structures were discussed. Formation of the crystals is determined by the presence of the intermolecular O-HN hydrogen bond that occur between fenamic acids and acridine.

The Na-O bond in sodium fenamate.

The one-dimensional polymeric structure of sodium diaquafenamate-water (1/1) was studied by X-ray diffraction. The sodium cation is coordinated to one oxygen atom of the carboxylate group and to four water oxygen atoms. To characterize the Na-O bonds, the quantum theory of atoms in molecules (QTAIM) and noncovalent interaction (NCI) approaches have been used.

First oxido-bridged cubo-octahedral hexanuclear rhenium clusters.

The first discrete hexanuclear metal clusters with cores adopting the M6(μ-O)12 cubo-octahedral topology have been synthesized in the course of a simple one-pot reaction. We present a new class of rhenium clusters which are the first hexanuclear rhenium complexes with 12 bridging ligands and the first clusters with octahedrally arranged Re atoms bridged only by O atoms forming a unique cube-like Re6(μ-O)12 unit. Our synthetic strategy demonstrates a new approach to the syntheses of polynuclear rhenium complexes under mild conditions.

2,2'-[(1E,2E)-1,2-Bis(hy-droxy-imino)-ethane-1,2-di-yl]dipyridinium hexa-chloridorhenate(IV).

The title salt, (C(12)H(12)N(4)O(2))[ReCl(6)], consists of 2,2'-[(1E,2E)-1,2-bis-(hy-droxy-imino)-ethane-1,2-di-yl]dipyridinium cations and [ReCl(6)](2-) anions which are both located on inversion centres. Each cation consists of a glyoxime moiety attached to two protonated pyridine rings in ortho positions. In the crystal, E,E isomers of the cation are observed which differ in the spatial arrangement of the pyridine rings.

trans-Dioxidotetra-pyridine-rhenium(V) triiodide.

In the title salt, [ReO(2)(C(5)H(5)N)(4)]I(3), the cation and anion are both located on centres of symmetry. The Re(V) atom adopts a trans-ReO(2)N(4) octa-hedral coordination and short intra-molecular C-H⋯O contacts occur within the cation. In the crystal, the cations form layers perpendicular to [100] and a weak C-H⋯O inter-action links the cations.