Synthesis and structure of bismuth(III)-containing noncentrosymmetric phosphates, Cs3KBi2M4(PO4)6Cl (M = Mn, Fe). Monoclinic (Cc) and tetragonal (P43) polymorphs templated by chlorine-centered Cl(Bi2Cs) acentric units.

Single crystals of three new noncentrosymmetric (NCS) phosphates, α (1) and ß (2) forms of Cs(3)KBi(2)Mn(4)(PO(4))(6)Cl and α-Cs(3)KBi(2)Fe(4)(PO(4))(6)Cl (3), were grown in a reactive CsCl/KCl molten-salt media. Their structures were determined by single-crystal X-ray diffraction methods showing that the α form crystallizes in the space group Cc (No. 9), which is in one of the 10 NCS polar crystal classes, m (2/m) while the ß form crystallizes in P4(3) (No. 78) of another polar class, 4 (4/m). The unit cell parameters of the α form can be approximately correlated with that of the ß form via the 3 × 3 orientation matrix [0.5, 0.5, 0; -0.5, 0.5, 0; 0, 0, 2 sin ß]. The structures of these otherwise complicated phosphates exhibit two types of channels with circular and elliptical windows where the Cl-centered Cl(Bi(2)Cs) acentric unit is located. The neighboring acentric units are arranged in a parallel fashion in the α form, resulting in the monoclinic (Cc) lattice, but "antiparallel" in the ß form, thus giving the tetragonal (P4(3)) unit cell. 1-3 feature the compatible M-O-P unit that contains four crystallographically independent MO(x) (x = 4, 5) polyhedra, which are connected to the Cl(Bi(2)Cs) acentric unit through one short and one long M(II)···Cl bond. The compositions of 1 and 2 consist of three Mn(2+) (d(5)) and one Mn(3+) (d(4)) per formula unit and that of 3 has three Fe(2+) (d(6)) and one Fe(3+) (d(5)). Bond valence sums reveal that, in the α phase, the trivalent site adopts distorted tetrahedral M(1)(3+)O(4) coordination and, in the ß phase, distorted trigonal-bipyramidal M(4)(3+)O(5). Thus far, the iron phase has only been isolated in the α form presumably because of little extra stabilization energy gain if the Fe(2+) d(6) ion were to occupy the M(1)O(4) site. The possible origins pertaining to the structural differences in the α and ß forms are discussed.

Synthesis, characterization, and preliminary in vitro studies of vanadium(IV) complexes with a Schiff base and thiosemicarbazones as mixed-ligands.

[VO(Sal-L-tryp)(H2O)] 1 (where sal-L-tryp = N-salicylidene-L-tryptophanate) was used as a precursor to produce the novel complexes, [VO(Sal-L-tryp)(MeATSC)].1.5C2H5OH 2 (where MeATSC = 9-Anthraldehyde-N(4)-methylthiosemicarbazone), [VO(Sal-L-tryp)(N-Ethhymethohcarbthio)].H2O 3 (where N-Ethhymethohcarbthio = (E)-N-ethyl-2-(4-hydroxy-3-methoxybenzylidene)hydrazinecarbothioamide), and [VO(Sal-L-tryp)(acetylethTSC)].C2H5OH 4 (where acetylethTSC = (E)-N-ethyl-2-(1-(thiazol-2-yl)ethylidene)hydrazinecarbothioamide), by reaction with the respective thiosemicarbazone. The chemical and structural properties of these ligands and complexes were characterised by elemental analysis, ESI MS, FT-IR, UV-visible, ESR, 1H and 13C NMR spectroscopy, and X-ray crystallography. DMSO and DMSO-d6 solutions of compounds 1-4 were oxidised in air to produce vanadium(V) species which were verified by ESI MS and 51V NMR spectroscopy. Anti-cancer properties of compounds 2-4 were examined with three colon cancer cell lines, HTC-116, Caco-2, and HT-29, and also with non-cancerous colonic myofibroblasts, CCD18-Co. Compounds 2-3 exhibited less inhibitory effects in the CCD-18Co cells, indicating a possible cytotoxic selectivity towards colon cancer cells. In general, those compounds which exhibited anti-proliferative activity on cancer cells, but did not affect non-cancerous cells, may have a potential in chemotherapy.

Synthesis of internal fluorinated alkenes via facile aryloxylation of substituted phenols with aryl trifluorovinyl ethers.

Nucleophilic addition-elimination of ortho- or para-substituted phenols to aryl trifluorovinyl ethers (TFVEs) in N,N-dimethylformamide was studied. Using sodium hydride as a base afforded vinyl substitution products R-Ar-O-CF=CF-O-Ar-R', where R or R' = H, Br, OMe, tert-Bu, or Ph. The vinyl substitution products produced mixtures of (Z)/(E)-isomers and this isomer ratio was influenced by substitution with more sterically encumbered phenol nucleophiles. Reactions using caesium carbonate afforded addition products R-Ar-O-CHFCF(2)-O-Ar-R' whereas upon dehydrofluorination using sodium hydride produced vinyl substitution products. The preparation of vinyl substituted and addition products proceeded in overall good isolated yields and were elucidated using (1)H and (19)F NMR, GC-MS, and X-ray analysis. Vinyl substituted products were inert to UV light and chemical reactivity using common polymerization promoters. Thermal activation of the (Z)/(E)-fluoroolefin (-CF=CF-) was observed at an onset of 310 °C in nitrogen using differential scanning calorimetry (DSC) producing insoluble network material. The synthesis, characterization, and mechanism for stereoselectivity are discussed.

The diselanylbis(1,3-dimethyl-1H-imidazol-3-ium) dication stabilized by the polymeric catena-pentachloridotricuprate(I) anion.

In the title compound, catena-poly[diselanylbis(1,3-dimethyl-1H-imidazol-3-ium) [µ(3)-chlorido-tetra-µ(2)-chlorido-tricuprate(I)]], {(C(10)H(16)N(4)Se(2))[Cu(3)Cl(5)]}(n), the diselenide dication is stabilized by catena-[Cu(3)Cl(5)](2-) anions which associate through strong Cu-Cl bonds [average length = 2.3525 (13) Å] to form polymeric chains. The polymeric [Cu(3)Cl(5)](2-) anion contains crystallographically imposed twofold rotation symmetry, with distorted trigonal-planar and tetrahedral geometries around the two symmetry-independent Cu atoms. Likewise, the Se-Se bond of the cation is centered on a twofold rotation axis.

Probing the antioxidant action of selenium and sulfur using Cu(I)-chalcogenone tris(pyrazolyl)methane and -borate complexes.

Hydroxyl radical generated from the reaction of Cu(+) with hydrogen peroxide results in oxidative DNA damage, and this damage is implicated in aging, cancer, and many other diseases. Selenium- and sulfur-containing compounds can act as antioxidants, and coordination of selenium and sulfur to copper is one explanation for this antioxidant activity. To determine how copper coordination results in antioxidant activity, biologically relevant tris(pyrazolyl)methane and borate Cu(+) complexes of the formulas Tp*Cu(L) and [Tpm(R)Cu(L)](+), where (L = N, N'-dimethylimidazole selone, dmise; N, N'-dimethylimidazole thione, dmit; Tp* = hydrotris(3,5-dimethylpyrazolyl)borate; Tpm(R) = tris(pyrazolyl)methane, R = H; Tpm, R = Me; Tpm*, R = iPr; Tpm(iPr)), have been synthesized and characterized. The structures of complexes Tp*Cu(Dmit), Tp*Cu(dmise), [Tpm(R)Cu(dmise)][BF(4)], and [Tpm(R)Cu(Dmit)][BF(4)] (where R = H; Tpm, R = Me; Tpm*, R = iPr; Tpm(iPr)) were determined by X-ray crystallography. All the Cu(+) centers adopt distorted tetrahedral coordination geometry, and Cu-Se and Cu-S distances for all the complexes are approximately 2.30 Å, and 2.20 Å, respectively. The effects of counterion and steric bulk at the 3 and 5 positions of the pyrazolyl ring on the structural and spectroscopic properties are discussed. Selone or thione coordination to copper significantly alters the Cu(+/2+) redox potential: Cu-selone complexes have Cu(2+/+) potentials from -283 to -390 mV, whereas those of Cu-thione complexes range from 70 to -232 mV versus NHE. The Cu-selone complexes have Cu(2+/+) potentials near or below that of the cellular reductant NADH (-324 mV). Thus, selenium and sulfur coordination to copper in biological systems may prevent the Cu(2+) reduction by NADH required for the catalytic formation of damaging hydroxyl radical.

In vitro biological studies and structural elucidation of fluoro-substituted phenyl acrylic acids.

BACKGROUND: Synthesis, characterization, and biological significance of different substituted phenyl acrylic acids have been studied. These acids are contributing a key role during synthesis of antimicrobial drugs. METHOD: The acids were prepared by condensation of various substituted phenyl acetic acids and aldehydes. o-piperonal was prepared using 2,3-methylenedioxy benzaldehyde. These phenyl acrylic acids were characterized by using analytical techniques, for example, Fourier transform infrared spectroscopy, multinuclear NMR (1H, 13C NMR), and GC-MS. The structure of crystalline products was also elucidated by X-ray crystallography. Small intermolecular and intramolecular weaker interactions were also studied by these characterization techniques. RESULTS: The geometry of compounds in solid and solution state has been studied. The presence of weaker interactions in these molecules is also observed which may increase the hydrolysis and lipophilicity and ultimately improve the activity against different microbes. CONCLUSION: The effect of different groups attached to the main rings and the presence of smaller interaction have been studied. Their factors may enhance the activity of these compounds.

Khayanolides from African mahogany Khaya senegalensis (Meliaceae): A revision.

Five khayanolides (1-O-acetylkhayanolide B 1, khayanolide B 2, khayanolide E 3, 1-O-deacetylkhayanolide E 4, 6-dehydroxylkhayanolide E 5) were isolated from the stem bark of African mahogany Khaya senegalensis (Meliaceae). Their structures and absolute configurations were determined through extensive spectroscopic analyses including MS, NMR, and single-crystal X-ray diffraction experiments. The results established that two previously reported khayanolides, 1alpha-acetoxy-2beta,3alpha,6,8alpha,14beta-pentahydroxy-[4.2.1(10,30).1(1,4)]-tricyclomeliac-7-oate 6 and 1alpha,2beta,3alpha,6,8alpha,14beta-hexahydroxy-[4.2.1(10,30).1(1,4)]-tricyclomeliac-7-oate 7, were, in fact, 1-O-acetylkhayanolide B 1 and khayanolide B 2, and that the two reported phragmalin derivatives, methyl 1alpha-acetoxy-6,8alpha,14beta,30beta-tetrahydroxy-3-oxo-[3.3.1(10,2).1(1,4)]-tricyclomeliac-7-oate 8 and methyl 1alpha,6,8alpha,14beta,30beta-pentahydroxy-3-oxo-[3.3.1(10,2).1(1,4)]-tricyclomeliac-7-oate 9, were, in fact, khayanolide E 3 and 1-O-deacetylkhayanolide E 4, respectively. Based on the results from this study and consideration of the biogenetic pathway, the methyl 6-hydroxyangolensate in African mahogany K. senegalensis should have a C-6 S configuration while methyl 6-hydroxyangolensate in genuine mahogany Swietenia species should have a C-6 R configuration.

The molecular structure and vibrational spectra of N-(2,2-diphenylacetyl)-N'-(naphthalen-1yl)-thiourea by Hartree-Fock and density functional methods.

N-(2,2-Diphenylacetyl)-N'-(naphthalen-1yl)-thiourea (PANT) has been synthesized and characterized by elemental analysis, IR spectroscopy and (1)H NMR spectroscopy. The crystal and molecular structure of the title compound has been determined from single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1, Z=2 with a=10.284(2)A, b=10.790(2)A, c=11.305(2)A, alpha=64.92(3) degrees , beta=89.88(3) degrees , gamma=62.99(3) degrees , V=983.7(3)A(3) and D(calc)=1.339Mg/m(3). The molecular structure, vibrational frequencies and infrared intensities of PANT were calculated by the Hartree-Fock and density functional theory methods (BLYP and B3LYP) using the 6-31G* basis set. The calculated geometric parameters were compared to the corresponding X-ray structure of the title compound. We obtained 22 stable conformers for the title compound; however Conformer 1 is approximately 9.53kcal/mol more stable than Conformer 22. The comparison of the theoretical and experimental geometry of the title compound shows that the X-ray parameters fairly well reproduce the geometry of Conformer 17. The harmonic vibrations computed for this compound by the B3LYP/6-31G* method are in good agreement with the observed IR spectral data. Theoretical vibrational spectra of the title compound were interpreted by means of PEDs using the VEDA 4 program. A general better performance of the investigated methods was calculated by PAVF 1.0 program.

Synthesis and characterization of N-(Arylcarbamothioyl)-cyclohexanecarboxamide derivatives: the crystal structure of N-(naphthalen-1-ylcarbamothioyl)cyclohexanecarboxamide.

A number of N-(arylcarbamothioyl)cyclohexanecarboxamide derivatives (aryl substituents: phenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, o-tolyl, p-tolyl, 3-methoxyphenyl, 4-methoxyphenyl and naphthalen-1yl) have been synthesized. The compounds obtained were characterized by elemental analyses, IR spectroscopy and (1)H-NMR spectroscopy. N-(naphthalen-1-ylcarbamothioyl)cyclohexanecarboxamide, H(2)L(9), was also characterized by a single crystal X-ray diffraction study. This compound, C(18)H(20)N(2)OS, crystallizes in the triclinic space group Pi, with Z = 2, and unit cell parameters a = 6.9921(14) A, b = 11.002(2) A, c = 12.381(3) A, alpha = 113.28(3) degrees, beta = 99.38(3) degrees, and gamma = 101.85(3) degrees. The cyclohexane ring adopts a chair conformation. The molecular conformation of the compound is stabilized by an intramolecular (N2-H2***O1) hydrogen bond which forms a pseudo-six-membered ring.

K(3)(Sc(0.875)Nb(0.125))Nb(2)O(9)H(1.75): a new scandium niobate with a unique cage structure.

Potassium scandium niobate hydroxide, K(3)(Sc(0.875)Nb(0.125))Nb(2)O(9)H(1.75), is a new scandium niobate with a unique cage structure. The structure contains two non-equivalent K(+) sites (3m and 6m2 site symmetry), one disordered Sc(3+)/Nb(5+) site (3m site symmetry), one Nb(5+) site (3m site symmetry), two O(2-) sites (m and mm2 site symmetry) and one H(+) site (m site symmetry). Both scandium and niobium have octahedral environments, which combine to form cages around potassium. One K atom lies in a cube-like cage built of seven octahedra, while the other K atom is encapsulated by an eight-membered trigonal face-bicapped prism. The cages form sheets that extend along the ab plane.

1,3-Bis(4-tert-butyl-benz-yl)-4,5-dihydro-imidazolium chloride monohydrate.

In the title compound, C(25)H(35)N(2) (+)·Cl(-)·H(2)O, the imidazolidine ring adopts a twisted conformation, with a pseudo-twofold axis passing through the N-C-N carbon and the opposite C-C bond. The N-C-N fragment of the imidazolidine ring shows some degree of both double- and single-bond character due to partial electron delocalization. One of the tert-butyl groups is disordered over two conformations with occupancies of 0.714 (8) and 0.286 (8). In the crystal, O-H⋯Cl and C-H⋯O hydrogen bonds help to establish the packing.

Dichlorido[1-(2-methyl-benz-yl)-3-(η-2,4,6-trimethyl-benz-yl)-1H-2,3-dihydro-benzimidazol-2-yl-idene]ruthenium(II) dichloro-methane solvate.

The title complex, [RuCl(2)(C(25)H(26)N(2))]·CH(2)Cl(2), is best thought of as containing an octa-hedrally coordinated Ru center with the arene occupying three sites. Two Ru-Cl bonds and one Ru-carbene bond complete the distorted octa-hedron. The carbene portion of the ligand is a benzimidazole ring. This ring is connected to the C(6)H(2)(CH(3))(3) arene group by a CH(2) bridge. This leads to a system with very little apparent strain. A dichloro-methane solvent mol-ecule completes the crystal structure. Further stabilization is accomplished via C-H⋯N and C-H⋯Cl interactions.

1-(1H-Benzimidazol-1-ylmeth-yl)-3-[2-(di-isopropyl-amino)eth-yl]-1H-benzimid-azolium bromide 0.25-hydrate.

The title N-heterocyclic carbene derivative, C(23)H(30)N(5) (+)·Br(-)·0.25H(2)O, was synthesized using microwave heating and was characterized by (1)H and (13)C NMR spectroscopy and a single-crystal X-ray diffraction study. The structure of the title compound are stabilized by a network of intra- and inter-molecular C-H⋯Br hydrogen-bonding inter-actions. The crystal structure is further stabilized by π-π stacking inter-actions between benzene and imidazole fragment rings of parallel benzo[d]imidazole rings, with a separation of 3.486 (3) Šbetween the centroids of the benzene and imidazole rings. There is also an inter-molecular C-H⋯π inter-action in the crystal structure. The C-N bond lengths for the central benzimidazole ring are shorter than the average single C-N bond, thus showing varying degrees of double-bond character and indicating partial electron delocalization within the C-N-C-N-C fragment. The isopropyl group is disordered over two sites with occupancies of 0.792 (10) and 0.208 (10).

1,3-Bis(2-thienylmeth-yl)-4,5-dihydro-imidazolium trichlorido(η-p-cymene)ruthenate(II).

The asymmetric unit of the title compound, (C(13)H(15)N(2)S(2))[RuCl(3)(C(10)H(14))], contains a 1,3-(2-thienylmeth-yl)-4,5-dihydro-imidazolium cation and a trichlorido(η(6)-p-cymene)ruthenate(II) anion. The thio-phene rings of the cation are disordered by an 180° rotation about the thio-phene-CH(2) bonds with occupancies of 0.847 (5)/0.153 (5) and 0.700 (5)/0.300 (5), respectively. The Ru atom exhibits a distorted octa-hedral coordination with the benzene ring of the p-cymene ligand formally occupying three sites and three Cl atoms occupying the other three sites. The short C-N bond lengths in the imidazoline ring indicate partial electron delocalization within the N-C-N fragment. Cation and anions are connected through five inter-molecular C-H⋯Cl hydrogen bonds and one C-H⋯π hydrogen bond, forming a three-dimensional hydrogen-bonded network.

A two-dimensional organic-inorganic hybrid compound, poly[(ethylenediamine)tri-µ-oxido-oxidocopper(II)molybdenum(VI)].

A new organic-inorganic two-dimensional hybrid compound, [CuMoO(4)(C(2)H(8)N(2))], has been hydro-thermally synthesized at 443 K. The unit cell contains layers composed of CuN(2)O(4) octa-hedra and MoO(4) tetra-hedra. Corner-sharing MoO(4) and CuN(2)O(4) polyhedra form CuMoO(4) bimetallic sites that are joined together through O atoms, forming an edge-sharing Cu(2)Mo(2)O(4) chain along the c axis. The one-dimensional chains are further linked through bridging O atoms that join the Cu and Mo atoms into respective chains along the b axis, thus establishing layers in the bc plane. The ethyl-enediamine ligand is coordinated to the Cu atom through its two N atoms and is oriented perpendicularly to the two-dimensional -Cu-O-Mo- layers. The average distance between adjacent layers, as calculated by consideration of the closest and furthest distances between two layers, is 8.7 Å. The oxidation states of the Mo and Cu atoms of VI and II, respectively, were confirmed by bond-valence sum calculations.

1,3-Bis(thio-phen-2-ylmeth-yl)-3,4,5,6-tetra-hydro-pyrimidinium trichlorido(η-p-cymene)ruthenate(II).

The asymmetric unit of the title compound, (C(14)H(17)N(2)S(2))[Ru(C(10)H(14))Cl(3)], contains a 1,3-bis-(thio-phen-2-ylmeth-yl)-3,4,5,6-tetra-hydro-pyrimidinium cation and a trichlorido(η(6)-p-cymene)ruthenate(II) anion. The Ru atom exhibits a distorted octa-hedral coordination with the benzene ring of the p-cymene ligand formally occupying three sites and three chloride atoms occupying the other three sites. The N-C bond lengths of the N-C-N unit of the pyrimidinium cation are shorter than the average single C-N bond length of 1.48 Å, thus showing double-bond character, indicating a partial electron delocalization within the N-C-N fragment. The pyrimidine ring has an envelope conformation. Four inter-molecular C-H⋯Cl hydrogen bonds generate a three-dimensional hydrogen-bonded framework.

Bromido[1-(η-4-tert-butyl-benz-yl)-3-(2,4,6-trimethyl-benz-yl)benzimidazol-2-yl-idene]chloridoruthenium(II).

A new ruthenium complex, [RuBrCl(C(28)H(32)N(2))], has been synthesized and characterized by elemental analysis, (1)H NMR, (13)C NMR, IR-spectroscopy and a single-crystal X-ray diffraction study. The Ru atom in this complex is best described as having a considerably distorted octa-hedral coordination environment with the arene occupying three coordination sites. Two further coordination sites are occupied by chloride and bromide ligands, while the sixth site is occupied by the carbene. The carbene portion of the ligand is a benzimidazole ring. This ring is connected to the C(6)H(4)C(CH(3))(3) arene by a CH(2) bridge. This leads to a system with very little apparent strain. The two halogen atoms are disordered between Br and Cl. Two partial Cl atoms share the same sites as two partial Br atoms so that the title compound effectively has one Cl and one Br atom. C-H⋯X (X = Cl, Br) hydrogen bonds help to stabilize the crystal structure.

1,3-Bis[4-(dimethyl-amino)benz-yl]-4,5,6,7-tetra-hydro-1H-1,3-diazepan-2-ium chloride.

The title N-heterocyclic carbene derivative, C(23)H(33)N(4) (+)·Cl(-), has been synthesized and characterized by elemental analysis, (1)H and (13)C NMR, IR spectroscopy and a single-crystal X-ray diffraction study. Ions of the title compound are linked by three C-H⋯Cl inter-actions. The seven-membered 1,3-diazepane ring has a form inter-mediate between twist-chair and twist-boat.

1-(2-Phenyl-benz-yl)-3-(2,4,6-trimethyl-benz-yl)imidazolidinium bromide.

In the title salt, C(26)H(29)N(2) (+)·Br(-), which may serve as a precursor for N-heterocyclic carbenes, the imidazolidine ring adopts a twist conformation with a pseudo-twofold axis passing through the N-C-N carbon and the opposite C-C bond. The N-C-N bond angle [113.0 (4)°] and C-N bond lengths [1.313 (6) and 1.305 (6) Å] confirm the existence of strong resonance in this part of the mol-ecule. In the crystal, a C-H⋯Br inter-action is present. The dihedral angle between the biphenyl rings is 64.3 (2)° and the phenyl rings make angles of 76.6 (3) and 18.5 (3)° with the plane of the imidazolidine ring.

1-(4-tert-Butyl-benz-yl)-3-(3,4,5-tri-methoxy-benz-yl)benzimidazolium bromide monohydrate.

A novel N-heterocyclic carbene derivative, C(28)H(33)N(2)O(3) (+)·Br(-)·H(2)O, was synthesized and characterized by elemental analysis, (1)H and (13)C-NMR and IR spectroscopy and a single-crystal X-ray diffraction study. Ions of the title compound are linked by π⋯π stacking inter-actions (face-face separation 3.441 Å) and C-H⋯Br and O-H⋯Br inter-actions. Intra- and intermolecular C-H⋯O inter-actions are also present. The C-N bond lengths for the compound [1.329 (3), 1.325 (3), 1.389 (3) and 1.391 (3) Å] are all shorter than the average single C-N bond length of 1.48 Å, thus showing varying degrees of double-bond character.