Crystal structure of bis-(ethyl-enedi-thio)-tetra-thia-fulvalenium µ2-acetato-bis-[tri-bromido-rhenate(III)] 1,1,2-tri-chloro-ethane hemisolvate.

The asymmetric unit of the title salt, (C10H8S8)[Re2Br6(CH3COO)]·0.5C2H3Cl3, contains one bis-(ethyl-enedi-thio)-tetra-thia-fulvalene (ET) radical cation, one µ2-acetato-bis-[tri-bromido-rhenate(III)] anion and a 1,1,2-tri-chloro-ethane mol-ecule with half-occupancy disordered about a twofold rotation axis. The tetra-thia-fulvalene fragment adopts an almost planar configuration typical of the ET radical cation. The C atoms of both ethyl-enedi-thio fragments in the cation are disordered over two orientations with occupancy factors 0.65:0.35 and 0.77:0.23. In the anion, six Br atoms and a µ2-acetate ligand form a strongly distorted cubic O2Br6 coordination polyhedron around the Re2 dinuclear centre. In the crystal, centrosymmetrically related ET cations and Re2O2Br6 anions are linked into dimers by π-π stacking inter-actions [centroid-to-centroid distance = 3.826 (8) Å] and by pairs of additional Re⋯Br contacts [3.131 (3) Å], respectively. The dimers are further packed into a three-dimensional network by non-directional inter-ionic electrostatic forces and by C-H⋯Br and C-H⋯S hydrogen bonds. The disordered 1,1,2-tri-chloro-ethane mol-ecules occupy solvent-accessible channels along the b axis.

Crystal structure of di-µ-isobutyrato-κ(4) O:O'-bis-[cis-di-chlorido-(dimethyl sulfoxide-κS)rhenium(III)].

The title compound, [Re2(C3H7COO)2Cl4{(CH3)2SO}2], comprises binuclear complex mol-ecules [Re-Re = 2.24502 (13) Å] involving cis-oriented double carboxyl-ate bridges, four equatorial chloride ions and two weakly bonded O atoms from dimethyl sulfoxide ligands in the axial positions at the Re(III) atoms. In the crystal, mol-ecules are linked into corrugated layers parallel to (101) by very weak C-H⋯Cl and C-H⋯O hydrogen-bonding inter-actions. C-H⋯Cl hydrogen bonding provides the links between layers to consolidate a three-dimensional framework.

Crystal structure of cis-bis-(µ-ß-alanine-κ(2) O:O')bis[tri-chlorido-rhenium(III)](Re-Re) sesquihydrate.

The structure of the title compound, [Re2Cl6(C3H7NO2)2]·1.5H2O, comprises a dinuclear complex cation [Re-Re = 2.2494 (3) Å] involving cis-oriented double carboxyl-ate bridges, four equatorial chloride ions and two weakly bonded chloride ligands in the axial positions at the two rhenium(III) atoms. In the crystal, two complex mol-ecules and two water mol-ecules constitute hydrogen-bonded dimers, while an extensive hydrogen-bonding network involving the groups of the zwitterionic ligand is important for generation of the framework. An additional partially occupied water molecule is disordered over two sets of sites about a symmetry centre with a site-occupancy ratio of 0.3:0.2.

Synthesis, X-ray structure, interactions with DNA, remarkable in vivo tumor growth suppression and nephroprotective activity of cis-tetrachloro-dipivalato dirhenium(III).

In this study we report the synthesis, the X-ray crystal structure and the in vivo tumor growth suppression and nephroprotective activity of bis-dimethylsulfoxide-cis-tetrachlorodi-µ-pivalatodirhenium(III), cis-Re2[(CH3)3CCOO]2Cl4·2(CH3)2SO (I). The interactions of I with DNA were also investigated by electrophoretic mobility shift assays, electronic absorption titrations, ΔTm and viscosity measurements, which indicate that compound I interacts relatively strongly with the DNA (Kb 2.2×10(3)M(-1)), most likely by forming covalent interstrand cross-links, and by kinking and unwinding supercoiled DNA; moreover, DNA cleavage by I is enhanced in the presence of redox-active species. The in vivo antitumor activity of I is considerable and is accompanied by significant elimination of red blood cell and kidney damage. Remarkably, compound I in combination with cisplatin (combined Re-Pt antitumor system) led to suppression of tumor growth or complete tumor elimination. The antihemolytic and nephroprotective abilities of I only or as a part of the Re-Pt antitumor system were established and a possible mechanism for the influence of I on these properties, involving erythropoietin production, is proposed.

Synthesis, characterization, in vivo antitumor properties of the cluster rhenium compound with GABA ligands and its synergism with cisplatin.

A new dirhenium(III) complex cis-[Re2(GABA)2Cl5(H2O)]Cl.2H2O with zwitterionic gamma-aminobutyrate ligands was prepared and characterized by spectral methods and crystallography. The structure of the compound is comprised of dinuclear complex cations (Re-Re 2.2437(3) A) involving cis-oriented double carboxylate bridges, four equatorial chloride ions and two weakly bonded aqua and chloride ligands in the axial positions at two rhenium centers (Re-O 2.363(3), Re-Cl 2.6735(12) A). Antitumor properties of the complex were studied in the model of tumor growth with the use of Wistar rats inoculated by tumor carcinoma Guerink cells. The introduction of the compound in dosage according to the scheme of antioxidant therapy, inhibited the tumor growth by ca. 60% and led to stabilization of red blood cells in the tumor-bearing organisms. The combined introduction of the compound and cisplatin had a significant impact on the tumor growth and the disappearance of the tumors in most of the animals.