Polymorphism and Structural Variety in Sn(II) Carboxylate Coordination Polymers Revealed from Structure Solution of Microcrystals.

The crystal structures of four coordination polymers constructed from Sn(II) and polydentate carboxylate ligands are reported. All are prepared under hydrothermal conditions in KOH or LiOH solutions (either water or methanol-water) at 130-180 °C and crystallize as small crystals, microns or less in size. Single-crystal structure solution and refinement are performed using synchrotron X-ray diffraction for two materials and using 3D electron diffraction (3DED) for the others. Sn2 (1,3,5-BTC)(OH), where 1,3,5-BTC is benzene-1,3,5-tricarboxylate, is a new polymorph of this composition and has a three-dimensionally connected structure with potential for porosity. Sn(H-1,3,5-BTC) retains a partially protonated ligand and has a 1D chain structure bound by hydrogen bonding via ─COOH groups. Sn(H-1,2,4-BTC) contains an isomeric ligand, benzene-1,2,4-tricarboxylate, and contains inorganic chains in a layered structure held by hydrogen bonding. Sn2 (DOBDC), where DOBDC is 2,5-dioxido-benzene-1,4-dicarboxylate, is a new polymorph for this composition and has a three-dimensionally connected structure where both carboxylate and oxido groups bind to the tin centers to create a dense network with dimers of tin. In all materials, the Sn centers are found in highly asymmetric coordination, as expected for Sn(II). For all materials phase purity of the bulk is confirmed using powder X-ray diffraction, thermogravimetric analysis, and infrared spectroscopy.

Nanocrystalline Transition-Metal Gallium Oxide Spinels from Acetylacetonate Precursors via Solvothermal Synthesis.

The synthesis of mixed-metal spinels based on substituted γ-Ga2O3 is reported using metal acetylacetonate precursors in solvothermal reactions with alcohols as solvents at 240 °C. New oxides of Cr, Mn and Fe have been produced, all of which are formed as nanocrystalline powders, as seen by high-resolution transmission electron microscopy (HR-TEM). The first chromium-gallium mixed oxide is thus formed, with composition 0.33Ga1.87Cr0.8O4 ( = vacant site). X-ray absorption near-edge spectroscopy (XANES) at the chromium K-edge shows the presence of solely octahedral Cr3+, which in turn implies a mixture of tetrahedral and octahedral Ga3+, and the material is stable on annealing to at least 850 °C. An analogous manganese material with average chemical composition close to MnGa2O4 is shown to contain octahedral Mn2+, along with some Mn3+, but a different inversion factor to materials reported by conventional solid-state synthesis in the literature, which are known to have a significant proportion of tetrahedral Mn2+. In the case of iron, higher amounts of the transition metal can be included to give an Fe:Ga ratio of 1:1. Elemental mapping using energy dispersive X-ray spectroscopy on the TEM, however, reveals inhomogeneity in the distribution of the two metals. This is consistent with variable temperature 57Fe Mössbauer spectroscopy that shows the presence of Fe2+ and Fe3+ in more than one phase in the sample. Variable temperature magnetisation and electron paramagnetic resonance (EPR) indicate the presence of superparamagnetism at room temperature in the iron-gallium oxides.

Design, structural and spectroscopic elucidation, and the in vitro biological activities of new diorganotin dithiocarbamates.

The reaction of 2,2-dimethoxy-N-methylethyllamine or 2-methyl-1,3-dioxolane with CS(2) in alkaline media produced two novel dithiocarbamate salts. Subsequent reactions with organotin halides yielded six new complexes: [SnMe(2){S(2)CNR(R(1))(2)}(2)] (1), [Sn(n-Bu)(2){S(2)CNR(R(1))(2)}(2)] (2), [SnPh(2){S(2)CNR(R(1))(2)}(2)] (3), [SnMe(2){S(2)CNR(R(2))(2)}(2)] (4), [Sn(n-Bu)(2){S(2)CNR(R(2))(2)}(2)] (5), [SnPh(2){S(2)CNR(R(2))(2)}(2)] (6), where R = methyl, R(1) = CH(2)CH(OMe)(2), and R(2) = 2-methyl-1,3-dioxolane. All compounds were identified in terms of infrared, (1)H and (13)C NMR, and the complexes were also characterized using (119)Sn NMR, (119)Sn Mössbauer and X-ray crystallography. The biological activity of all derivatives has been screened in terms of IC(90) and IC(50) against Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Penicillium citrinum, Curvularia senegalensis, Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Streptococcus sanguinis, Escherichia coli, Citrobacter freundii, Salmonella typhimurium, and Pseudomonas aeruginosa and the results correlated well with a performed study of structure-activity relationship (SAR). Complexes (3), (5) and (6) displayed the best IC(90) and IC(50) in the presence of the fungi, greater than that of miconazole, used as control drug.

fac-(2-Amido-ethyl-κC,O)trichlorido(urea-κO)tin(IV).

The Sn atom in the title compound, [Sn(C(3)H(6)NO)Cl(3)(CH(4)N(2)O)], is octa-hedrally coordinated within a CCl(3)NO donor set provided by a chelating amido-ethyl ligand (C and O), a urea-O atom and three facially arranged Cl atoms. Systematic variations in the Sn-Cl bond distances are correlated with the relative trans influence exerted by the C and carbonyl-O atoms. The three-dimensional crystal packing is stabilized by N-H⋯O and N-H⋯Cl hydrogen bonds.

(2-Carbamoylethyl-κC,O)triiodidotin(IV).

Two independent but virtually identical mol-ecules comprise the asymmetric unit of the title compound, [Sn(C(3)H(6)NO)I(3)]. The CI(3)O coordination geometry around the Sn(IV) atom is defined by a chelating carbamoylethyl ligand (C(1),O-bidentate) and three I atoms, and is based on a distorted trigonal bipyramid with the carbonyl O atom occupying a position trans to one of the I atoms which forms the longer of the Sn-I bonds. The independent mol-ecules are linked via N-H⋯O hydrogen bonds, which leads to the formation on an eight-membered amide {⋯HNCO}(2) synthon. N-H⋯I hydrogen-bonding inter-actions are also present between neighbouring mol-ecules.

5-{[(E)-2-(4-Iodo-phen-yl)hydrazinyl-idene]meth-yl}thio-phene-2-carbaldehyde.

The title compound, C(12)H(9)IN(2)OS, has an overall U-shape, with a dihedral angle of 21.4 (3)° between the thio-phene and benzene rings. In the crystal, supra-molecular chains mediated by N-H⋯O hydrogen bonds are formed along the b-axis direction.

(E)-1-(3-Nitro-phen-yl)-2-({5-[(1E)-2-(3-nitro-phen-yl)hydrazin-1-ylidenemeth-yl]-2-thien-yl}methyl-idene)hydrazine.

The title mol-ecule, C(18)H(14)N(6)O(4)S, adopts a U-shape with the aromatic groups lying syn and oriented in the same direction as the thio-phene S atom. Twists away from planarity are evident with the maximum deviation being found for a terminal nitro group: C/C/N/O = 19.0 (3)°. The conformation about each of the C=N bonds is E. In the crystal, centrosymmetrically related mol-ecules are connected via N-H⋯O(nitro) hydrogen bonds, forming 14-membered {⋯HNC(3)NO}(2) synthons. These are linked into layers via C-H⋯O(nitro) inter-actions with the primary inter-actions between layers being of the type C-H⋯π, where the π-system is the thio-phene ring.

Triclinic form of bis-{di-µ-hydroxidobis[fac-aqua-tribromido-tin(IV)]} hepta-hydrate.

The asymmetric unit of the title hydrate, 2[Sn(H(2)O)(2)(OH)(2)Br(6)]·7H(2)O, comprises two [Br(3)(H(2)O)Sn(µ-OH)(2)SnBr(3)(OH(2))] units, but three independent mol-ecules as two of these are disposed about inversion centres, and seven water mol-ecules. In common with the monoclinic polymorph [Howie et al. (2005 ▶). Inorg. Chim. Acta, 358, 3283-3286], each of the dinuclear species features a central Sn(2)O(2) core, distorted octa-hedral Sn atom geometries defined by a Br(3)O(3) donor set, and an anti-disposition of the coordinated water mol-ecules. In the crystal, O(h)-H⋯O(w), O(a)-H⋯O(w), O(w)-H⋯O(w), and O(w)-H⋯Br (h = hydroxyl, a = aqua, w = water) hydrogen-bonding inter-actions generate a three-dimensional network.

fac-(2-Amido-ethyl-κC,O)aqua-tri-chlorido-tin(IV) 1,4,7,10,13,16-hexa-oxacyclo-octa-decane (2/1).

The asymmetric unit of the title compound, [Sn(C(3)H(6)NO)Cl(3)(H(2)O)](2)·C(12)H(24)O(6), comprises a six-coordinate tin complex and a 18-crown-6 mol-ecule, the latter disposed about a centre of inversion. The tin atom is coordinated by three Cl atoms, that define a facial arrangement, a chelating C-,O- ligand, and a water mol-ecule. The resulting CCl(3)O(2) donor set defines a distorted octa-hedral geometry. The tin-bound aqua ligand forms O-H⋯O hydrogen bonds to the centrosymmetric 18-crown-6 mol-ecule, resulting in a tri-mol-ecular aggregate. These assemble into a supra-molecular chain along the a axis being connected by N-H⋯O hydrogen bonds.

Bis(2-{[2,8-bis-(trifluoro-meth-yl)quinolin-4-yl](hydr-oxy)meth-yl}piperidin-1-ium) tetra-chloridodiphenyl-stannate(IV).

In the title salt, (C(17)H(17)F(6)N(2)O)(2)[Sn(C(6)H(5))(2)Cl(4)], the complete anion is generated by crystallograaphic inversion symmetry, giving a trans-SnC(2)Cl(4) octa-hedral coordination geometry for the metal atom. In the cation, the quinoline residue is almost normal to the other atoms, so that the ion has an L-shaped conformation [the C-C-C-C torsion angle linking the fused-ring systems is 100.9 (7)°]; the six-membered piperidin-1-ium ring has a chair conformation. An intra-molecular N-H⋯O inter-action occurs. In the crystal, N-H⋯Cl and O-H⋯Cl hydrogen bonds link the components into a supra-molecular chain propagating along the a axis. C-H⋯Cl inter-actions are also present.

(E)-1-Phenyl-2-({5-[(1E)-(2-phenyl-hydrazin-1-yl-idene)meth-yl]-2-thien-yl}methyl-idene)hydrazine.

The title mol-ecule, C(18)H(16)N(4)S, adopts a U-shape with the aromatic groups lying syn and orientated in the same direction as the thio-phene S atom. The conformation about each of the C=N bonds is E. Overall, the mol-ecule is curved as seen in the dihedral angle of 30.26 (19)° formed between the terminal benzene rings. In the crystal, supra-molecular chains along the c axis are formed by a combination of N-H⋯N hydrogen bonds and N-H⋯π inter-actions.

meso-1-{[2-(Propyl-1-sulfin-yl)eth-yl]sulfin-yl}propane.

The title mol-ecule, C(8)H(18)O(2)S(2), is disposed about a centre of inversion implying an anti-disposition of the sulfinyl-O atoms; the terminal n-propyl group has an extended conformation. The crystal packing is dominated by C-H⋯O inter-actions, which lead to the formation of supra-molecular arrays in the bc plane.

Bis(phenyl-sulfin-yl)methane.

Two independent mol-ecules comprise the asymmetric unit of the title compound, C(13)H(12)O(2)S(2), which differ in terms of minor variations in the relative orientations of the benzene rings [the O-S-C-C torsion angles for the first independent mol-ecule are -6.66 (17) and -12.88 (19)° compared with -21.70 (18) and 4.83 (16)° for the second mol-ecule]. Supra-molecular chains sustained by C-H⋯O contacts and aligned along the a axis are found in the crystal structure. These are held in place in the three dimensional structure by C-H⋯π inter-actions.

Synthesis, characterization and biocidal activity of new organotin complexes of 2-(3-oxocyclohex-1-enyl)benzoic acid.

The reaction of 1,3-cyclohexadione with 2-aminobenzoic acid has produced the 2-(3-oxocyclohex-1-enyl)benzoic acid (HOBz). Subsequent reactions of the ligand with organotin chlorides led to [Me(2)Sn(OBz)O](2) (1), [Bu(2)Sn(OBz)O](2) (2), [Ph(2)Sn(OBz)O](2) (3), [Me(3)Sn(OBz)] (4), [Bu(3)Sn(OBz)] (5) and [Ph(3)Sn(OBz)] (6). All complexes have been fully characterized. In addition the structure of complexes (2) and (4) have been authenticated by X-ray crystallography. The biological activity of all derivatives has been screened against Cryptococcus neoformans and Candida albicans. In addition we have performed toxicological testes employing human kidney cell. The complexes (3), (5) and (6) displayed the best values of inhibition of the fungus growing, superior to ketoconazole. Compound (5) presented promising results in view of the antifungal and cytotoxicity assays.

Bis[2-(ethoxy-carbonyl-amino)ethan-aminium] hexa-bromidostannate.

In the title salt, (C(5)H(13)N(2)O(2))(2)[SnBr(6)], the Sn atom (site symmetry ) exists in a slightly distorted octa-hedral geometry. The cation is non-planar as the terminal CH(2)NH(3) (+) residue lies below the plane defined by the remaining non-H atoms. In the crystal, cations associate via N-H⋯O hydrogen bonds involving the ammonium and carbonyl residues, forming a 14-membered {⋯HNC(2)NCO}(2) synthon. The cations and anions are arranged in alternating layers arranged along the a-axis direction, the major association between them being N-H⋯Br contacts.

Bis(2-ethoxy-carbonyl-ethyl-κC,O)(2-thioxo-1,3-dithiole-4,5-dithiol-ato-κS,S)tin(IV).

In the title compound, [Sn(C(5)H(9)O(2))(2)(C(3)S(5))], the immediate environment around the Sn centre is defined by two S and two C atoms that define an approximately tetra-hedral geometry. The close approach of the pendant carbonyl O atoms [Sn-O = 2.577 (3) and 2.573 (3) Å] increases the coordination number to six. Supra-molecular chains are formed along the a axis in the crystal structure owing to the presence of C-H⋯O contacts.

2-[(E)-(1H-Pyrrol-2-ylmethyl-idene)hydrazinyl]pyridine monohydrate.

The title hydrate, C(10)H(10)N(4)·H(2)O, shows a small twist in the hydro-zone derivative, the dihedral angle between the pyridine and pyrrole rings being 11.08 (12)°. The pyridine and pyrrole N atoms lie to the same side of the mol-ecule being sustained in place by hydrogen-bonding inter-actions with the water mol-ecule. Further inter-molecular O-H⋯N and N-H⋯O hydrogen bonding leads to the formation of supra-molecular arrays in the ab plane.

Dibenzo-18-crown-6.

The asymmetric unit of the title compound, C(20)H(24)O(6), contains two mol-ecules that are identical within standard deviations concerning bond lengths and angles as well as their conformations. In the crystal structure, weak C-H⋯O inter-actions help to consolidate the packing.

Redetermination of phenyl-hydrazinium chloride.

In the redetermined structure [Koo (1965 ▶). Bull. Chem. Soc. Jpn, 38, 286] of the title compound, C(6)H(9)N(2) (+)·Cl(-), the H atoms have been located and the hydrogen-bonding scheme established. A series of N-H⋯Cl and N-H⋯N hydrogen bonds leads to a layered network parallel to the (010) plane.

Structural studies and cytotoxic activity of N(4)-phenyl-2-benzoylpyridine thiosemicarbazone Sn(IV) complexes.

Structural studies and an investigation of the cytotoxic activity of Sn(IV) complexes with N(4)-phenyl-2-benzoylpyridine thiosemicarbazone (H2Bz4Ph) were carried out. The crystal and molecular structures of [Sn(2Bz4Ph)Cl3].CH3CH2OH (1) and [Sn(2Bz4Ph)BuCl2].H2O (Bu = butyl group) (2) were determined. Both compounds present octahedral coordination geometry with the 2Bz4Ph anionic ligand behaving as tridentate on the metal ion. A comparative study of the structures of these compounds along with that of [Sn(2Bz4Ph)Bu2Cl] (3) determined before is presented. The cytotoxicity of H2Bz4Ph and its Sn(IV) complexes was investigated against the MCF-7, TK-10 and UACC-62 human tumor cell lines. Among the three complexes, 3 proved to be better as cytotoxic agent than the clinically used drug etoposide. H2Bz4Ph and all complexes were able to induce apoptosis in UACC-62 cells.