Syntheses, crystal structures and Hirshfeld surface analyses of bis-(2-mercaptobenzimidazole)-bromo- and iodo-copper(I) complexes.

The title complexes, bromidobis(2,3-dihydro-1H-1,3-benzodiazole-2-thi-one)copper(I), [CuBr(C7H6N2S)2] (1), and bis(2,3-dihydro-1H-1,3-benzodiazole-2-thione)iodidocopper(I) acetone monosolvate, [CuI(C7H6N2S)2]·CH3COCH3 (2), were prepared by the reaction of copper(I) bromide/iodide with 2-mercaptobenzimidazole. Both complexes have mononuclear structures with the copper atom coordinated by two 2-mercaptobenzimidazole mol-ecules via their S atoms and one halide atom in an approximate trigonal-planar arrangement. In their extended structures, N-H⋯S hydrogen bonds and π-π contacts are found in both complexes; as a result of the acetone solvent mol-ecule in (2), N-H⋯O contacts are also observed. Hirshfeld surface analyses were carried out to aid in the visualization of these inter-actions, which showed that H⋯H contacts contribute 34.6% for (1) and 34.1% for (2) to the overall surface, followed by contributions from H⋯S/S⋯H, H⋯C/C⋯H and C⋯C contacts, respectively. As expected, H⋯O/O⋯H contacts are observed only in (2). The IR and 1H and 13C NMR spectra of (1) and (2) are described.

Crystal structure and Hirshfeld-surface analysis of (benzene-carbo-thio-amide-κS)bromido-bis-(tri-phenylphosphane-κP)silver(I).

The title complex, [AgBr(C7H7NS)(C18H15P)2], was obtained from the reaction of silver(I) bromide with benzene-carbo-thio-amide (C7H7NS) and tri-phenyl-phosphane (C18H15P) in the mixed solvent of aceto-nitrile and ethanol. The mononuclear complex exhibits a distorted tetra-hedral coordination geometry about the metal atom, arising from one S atom of a benzene-carbo-thio-amide ligand, two P atoms of two tri-phenyl-phosphane mol-ecules and one bromide ion. An intra-molecular N-H⋯Br hydrogen bond is observed and in the crystal structure, inversion dimers linked by pairs of N-H⋯Br and C-H⋯Br hydrogen bonds are observed. In addition, C-H⋯π inter-actions occur, leading to [101] chains. Hirshfeld-surface analyses are presented and discussed.

Why sildenafil and sildenafil citrate monohydrate crystals are not stable?

Sildenafil citrate was crystallized by various techniques aiming to determine the behavior and factors affecting the crystal growth. There are only 2 types of sildenafil obtaining from crystallization: sildenafil (1) and sildenafil citrate monohydrate (2). The used techniques were (i) crystallization from saturated solutions, (ii) addition of an antisolvent, (iii) reflux and (iv) slow solvent evaporation method. By pursuing these various methods, our work pointed that the best formation of crystal (1) was obtained from technique no. (i). Surprisingly, the obtained crystals (1) were perfected if the process was an acidic pH at a cold temperature then perfect crystals occurred within a day. Crystals of compound (2) grew easily using technique no. (ii) which are various polar solvents over a wide range of pH and temperature preparation processes. The infrared spectroscopy and nuclear magnetic resonance spectra fit well with these two X-ray crystal structures. The crystal structures of sildenafil free base and salt forms were different from their different growing conditions leading to stability difference.

Crystal structure of [3-amino-2-(phenyl-diazenyl)-pyridine]chlorido-(η(6)-p-cymene)-ruthenium(II) chloride.

The title compound, [RuCl(C10H14)(C11H10N4)]Cl is an Ru(II) complex in which an η (6) -p-cymene ligand, two N atoms of 3-amino-2-(phenyl-azo)pyridine and one Cl ion form a piano-stool coordination environment around the metal ion. In the crystal structure, N-H⋯Cl hydrogen bonds play an important role in the formation of the supramolecular zigzag chain along the a-axis direction. Disorder is observed for the isopropyl group with site-occupancy factors refined to 0.78 (5) and 0.22 (5).

Crystal structure of (µ-N-allyl-thio-urea-κ(2) S:S)bis-[µ-bis-(di-phenyl-phosphanyl)methane-κ(2) P:P']bis-[bromido-copper(I)] aceto-nitrile disolvate.

The reaction of cuprous bromide with a mixture of 1,1-bis-(di-phenyl-phosphan-yl)methane (dppm: C25H22P2) and N-allyl-thio-urea (ATU: C4H8N2S) in aceto-nitrile yielded the title solvated dinuclear complex, [Cu2Br2(C4H8N2S)(C25H22P2)2]·2C2H3N or [Cu2Br2(ATU)(dppm)2]·2CH3CN. Both Cu(+) ions adopt distorted tetra-hedral geometries, being coordinated by one terminal Br atom, one µ(2)-S atom of the bridging ATU ligand and two P atoms of the bridging dppm ligands. Within the complex, intra-molecular C-H⋯S, C-H⋯π, N-H⋯Br and π-π stacking inter-actions are observed. In the crystal, the components are linked by N-H⋯Br and C-H⋯N hydrogen bonds and weak π-π stacking inter-actions, generating chains propagating in the [100] direction.

Crystal structure of bis-[µ-1,2-bis-(di-phenyl-phosphan-yl)ethane-κ(2) P:P']bis[(N,N'-di-ethyl-thio-urea-κS)iodidocopper(I)].

The binuclear title complex, [Cu2I2(C26H24P2)2(C5H12N2S)2], lies about an inversion centre. The Cu(I) atom displays a distorted tetra-hedral coordination geometry defined by one S atom of an N,N'-di-ethyl-thio-urea ligand, two P atoms derived from two bridging 1,2-bis-(di-phenyl-phosphan-yl)ethane (dppe) ligands and one iodide ion. The dppe ligand bridges two symmetry-related Cu(I) ions, forming a 10-membered Cu2P4C4 ring. An intra-molecular N-H⋯I hydrogen bond is noted. In the crystal, N-H⋯I hydrogen bonds link complex mol-ecules into layers parallel to (-101).

Synthesis of gem-difluoromethylenated polycyclic cage compounds.

The synthesis of gem-difluoromethylenated polycyclic cage compounds, utilizing PhSCF2SiMe3 as a gem-difluoromethylene building block, is described. The fluoride-catalyzed nucleophilic addition of PhSCF2SiMe3 to both maleic anhydride-cyclopentadiene and maleic anhydride-cyclohexadiene adducts was accomplished with high stereoselectivity to provide the corresponding adducts that were treated with Grignard reagents, followed by acid-catalyzed lactonization to afford the corresponding γ-butyrolactones, each as a single isomer. These γ-butyrolactones underwent intramolecular radical cyclization to give the corresponding tetracyclic cage γ-butyrolactones, which were employed as precursors for the synthesis of gem-difluoromethylenated tetracyclic cage lactols or tetracyclic cage furans, upon treatment with Grignard reagents.

Asymmetric synthesis of gem-difluoromethylenated linear triquinanes via cascade gem-difluoroalkyl radical cyclization.

An asymmetric synthesis of gem-difluoromethylenated linear triquinanes is described exploiting the synthetic utilities of PhSCF2TMS (5) as a "(•)CF2(-)'' building block. The strategy involves fluoride-catalyzed nucleophilic addition of PhSCF2TMS (5) to chiral ketocyclopentenes 6 to provide silylated adducts 9 or alcohol derivatives 10 and 11. Subsequent cascade radical cyclization of the gem-difluoroalkyl radical generated from silylated adducts 9 or alcohols 10 and 11 afforded gem-difluoromethylenated linear triquinanes 16 as an approximate 1:1 mixture of two diastereomers (16A and 16B). Alternatively, a convenient asymmetric synthesis of gem-difluoromethylenated linear triquinanes 16A can be accomplished by oxidation of 16a (R = H) to provide ketotriquinane 17 followed by a highly stereoselective nucleophilic addition to 17 employing DIBAL, NaBH4, and various Grignard reagents.

Crystal structure of (benzene-carbo-thio-amide-κS)chloridobis-(tri-phenyl-phosphane-κP)silver(I).

In the mononuclear mixed-ligand title complex, [AgCl(C7H7NS)(C18H15P)2], the Ag(I) ion is four coordinated by one S atom of a benzene-carbo-thio-amide ligand, two P atoms of two tri-phenyl-phosphane ligands and one chloride ion, displaying a distorted tetra-hedral coordination geometry. In the crystal, pairs of N-H⋯Cl hydrogen bonds form inversion dimers. An intra-molecular N-H⋯Cl hydrogen bond is also observed.

Crystal structure of [3-(4,5-di-hydro-1,3-thia-zolin-2-yl-κN)-1,3-thia-zolidine-2-thione-κS (2)](1,3-thia-zol-idine-2-thione-κS (2))copper(I) nitrate.

The mononuclear complex salt, [Cu(C3H5NS2)(C6H8N2S3)]NO3, contains a [C9H13CuN3S5](+) cation and an NO3 (-) anion. All of the non-H atoms of the cation lie on a mirror plane, as do the N and one O atom of the nitrate anion, such that the planes of the cation and anion are mutually orthogonal. The cationic complex adopts a slightly distorted trigonal-planar geometry about the Cu(I) cation. In the crystal, layers parallel to (010) are generated by N-H⋯O hydrogen bonds, supported by short S⋯O [3.196 (4) and 3.038 (3) Å] and S⋯S contacts [3.4392 (13) Å]. Adjacent layers are linked by C-H⋯O hydrogen bonds and weak π-π stacking inter-actions [centroid-centroid distance = 4.0045 (10) Å] between the thia-zoline rings, forming a three-dimensional network. This stacking also imposes a close contact, of approximately 3.678 Å, between the Cu(I) cations and the centroids of the six-membered chelate rings of mol-ecules in adjacent layers.

Crystal structure of a two-dimensional grid-type iron(II) coordination polymer: poly[[di-aqua-tetra-µ-cyanido-diargentate(I)iron(II)] trans-1,2-bis(pyridin-2-yl)ethyl-ene disolvate].

In the title compound, {[Ag2Fe(CN)4(H2O)2]·2C12H10N2} n , the asymmetric unit contains one Fe(II) cation, two water mol-ecules, two di-cyanido-argentate(I) anions and two uncoordinating 1,2-bis-(pyridin-2-yl)ethyl-ene (2,2'-bpe) mol-ecules. Each Fe(II) atom is six-coordinated in a nearly regular octa-hedral geometry by four N atoms from di-cyanido-argentate(I) bridges and two coordinating water mol-ecules. The Fe(II) atoms are bridged by di-cyanido-argentate(I) units to give a two-dimensional layer with square-grid spaces. The inter-grid spaces with inter-layer distance of 6.550 (2) Šare occupied by 2,2'-bpe guest mol-ecules which form O-H⋯N hydrogen bonds to the host layers. This leads to an extended three-dimensional supra-molecular architecture. The structure of the title compound is compared with some related compounds containing di-cyanido-argentate(I) ligands and N-donor organic co-ligands.

Poly[tris-(µ-4,4'-bi-pyridine-κ(2) N:N')bis(dimethyl sulfoxide-κO)tetra-kis-(thiocyanato-κN)dicobalt(II)].

The asymmetric unit of the title compound, [Co2(NCS)4(C10H8N2)3(C2H6OS)2] n , consists of one Co(II) atom, two thio-cyanate anions, one dimethyl sulfoxide mol-ecule and one and a half 4,4'-bi-pyridine mol-ecules. The half-molecule is completed by inversion symmetry. The Co(II) atom is coordin-ated in a distorted octa-hedral geometry by two N atoms from two thio-cyanate anions, one O atom from dimethyl sulfoxide as a terminal ligand and three N atoms from three 4,4'-bi-pyridine mol-ecules as bridging ligands linking the cations, with a Co⋯Co separation of 11.5964 (5) Å. This generates a two-dimensional structure parallel to (-103). A C-H⋯S hydrogen bond links the layers into a three-dimensional supra-molecular framework. The layers are stacked in an ABC fashion preventing the occurrence of inter-layer void space and hence leading to the absence of lattice solvent and/or organic guest mol-ecules in the structure.

(N-Phenyl-thio-urea-κS)bis-(tri-phenylphosphane-κP)silver(I) nitrate.

In the title salt, [Ag(C7H8N2S)(C18H15P)2]NO3, the coordination geometry about the Ag(I) atom is shallow trigonal pyramidal, with the metal atom displaced by 0.372 (1) Šfrom the plane of the P and S atoms. In the crystal, the cations are linked to the anions by N-H⋯O hydrogen bonds, generating tetra-mers (two cations and two anions), which feature R 2 (2)(8) and R 4 (4)(8) loops. The cations are linked by weak C-H⋯π inter-actions, generating a three-dimensional network.

Bis(2,4,6-tri-amino-pyrimidin-1-ium) sulfate penta-hydrate.

The asymmetric unit of the title salt, 2C4H8N5 (+)·SO4 (2-)·5H2O, contains four 2,4,6-tri-amino-pyrimidinium (TAPH(+)) cations, two sulfate anions and ten lattice water mol-ecules. Each two of the four TAPH(+) cations form dimers via N-H⋯N hydrogen bonds between the amino groups and the unprotonated pyrimidine N atoms [graph-set motif R 2 (2)(8)]. The (TAPH(+))2 dimers, in turn, form slightly offset infinite π-π stacks parallel to [010], with centroid-centroid distances between pyrimidine rings of 3.5128 (15) and 3.6288 (16) Å. Other amino H atoms, as well as the pyrimidinium N-H groups, are hydrogen-bonded to sulfate and lattice water O atoms. The SO4 (2-) anions and water mol-ecules are inter-connected with each other via O-H⋯O hydrogen bonds. The combination of hydrogen-bonding inter-actions and π-π stacking leads to the formation of a three-dimensional network with alternating columns of TAPH(+) cations and channels filled with sulfate anions and water mol-ecules. One of the sulfate anions shows a minor disorder by a ca 37° rotation around one of the S-O bonds [occupancy ratio of the two sets of sites 0.927 (3):0.073 (3)]. One water mol-ecule is disordered over two mutually exclusive positions with an occupancy ratio of 0.64 (7):0.36 (7).

The heterometallic cadmium-silver complex cis-bis[dicyanidoargentato(I)-κN]bis(5,5'-dimethyl-2,2'-bipyridyl-κ(2)N,N')cadmium(II) monohydrate.

In the title complex, [Ag2Cd(CN)4(C12H12N2)2]·H2O or cis-[Cd{Ag(CN)2}2(5,5'-dmbpy)2]·H2O, where 5,5'-dmbpy is 5,5'-dimethyl-2,2'-bipyridyl, the asymmetric unit consists of a discrete neutral [Cd{Ag(CN)2}2(5,5'-dmbpy)2] unit and a solvent water molecule. The Cd(II) cation is coordinated by two bidentate chelate 5,5'-dmbpy ligands and two monodentate [Ag(I)(CN)2](-) anions, which are in a cis arrangement around the Cd(II) cation, leading to an octahedral CdN6 geometry. The overall structure is stabilized by a combination of intermolecular hydrogen bonding, and Ag(I)···Ag(I) and π-π interactions, forming a three-dimensional supramolecular network.

A synthesis of γ-trifluoromethyl α,ß-unsaturated γ-butyrolactones using CF(3)SiMe(3) as a trifluoromethylating agent.

A general synthesis of γ-trifluoromethyl α,ß-unsaturated γ-butyrolactones is described. The fluoride-catalyzed nucleophilic addition of a trifluoromethyl (CF3) group generated from (trifluoromethyl)trimethylsilane (CF3SiMe3, Ruppert-Prakash reagent) to a masked maleic anhydride 1 (cyclopentadiene-maleic anhydride adduct) provides the corresponding adducts 2 with high stereoselectivity. The γ-trifluoromethyl α,ß-unsaturated γ-butyrolactones 4 were obtained after treatment of the adducts 2 with Grignard reagents, followed by flash-vacuum pyrolysis.

2-Amino-5-bromo-pyridin-1-ium (2-amino-5-bromo-pyridine-κN (1))trichloridozincate.

The structure of the title salt, (C5H6BrN2)[ZnCl3(C5H5BrN2)], consists of discrete 2-amino-5-bromo-pyridin-1-ium cations and distorted tetra-hedral (2-amino-5-bromo-pyridine)-tri-chlorido-zincate anions. In the crystal, the complex anions and cations are linked via N-H⋯Cl hydrogen bonds into layers parallel to (101). Short Br⋯Cl contacts of 3.4239 (11) and 3.4503 (12) Šare observed, as well as π-π stacking inter-actions between the pyridine and pyridinium rings, with alternating centroid-to-centroid distances of 3.653 (2) and 3.845 (2) Å.

(anti-Chlorido-thio-semicabazide-κS)bis-(tri-phenyl-phosphane-κP)copper(I) 0.48-hydrate.

In the mononuclear title complex, [CuCl(CH5N3S)(C18H15P)2]·0.48H2O, the Cu(I) ion is in a slightly distorted tetra-hedral coordination geometry formed by two P atoms from two tri-phenyl-phosphane ligands, one S atom from a thio-semicarbazide ligand and one chloride anion. An intra-molecular N-H⋯N hydrogen bond [graph-set motif S(5)] stabilizes the thio-semicarbazide ligand in its anti conformation, and an intra-molecular N-H⋯Cl hydrogen bond between the hydrazine N-H group and the chloride anion influences the arrangement and orientation of the ligands around the metal center. A weak intra-molecular C-H⋯Cl hydrogen bond is also present. In the crystal, complex mol-ecules are connected through N-H⋯Cl hydrogen bonds originating from the amide -NH2 group, and through O-H⋯S and O-H⋯Cl hydrogen bonds involving the solvent water mol-ecule. Both the direct N-H⋯Cl hydrogen bonds as well as the bridging hydrogen bonds mediated by the water mol-ecule connect the complex mol-ecules into zigzag chains that propagate along [010]. The solvent water mol-ecule is partially occupied, with a refined occupancy of 0.479 (7).

catena-Poly[silver(I)-bis-[µ-4-methyl-1H-1,2,4-triazole-3(4H)-thione-κ(2) S:S]-silver(I)-di-µ-thio-cyanato-κ(2) S:N;κ(2) N:S].

In the title one-dimensional coordination polymer, [Ag2(NCS)2(C3H5N3S)2] n , the Ag(I) atom adopts a distorted tetra-hedral AgNS3 geometry. Adjacent Ag(I) atoms in the [001] chain are alternately linked by pairs of bridging 4-methyl-1H-1,2,4-triazole-3(4H)-thione (Hmptrz) ligands (via their S atoms) and double thio-cyanate bridges linking through both S and N atoms (µ-1,3-SCN). An intra-chain N-H⋯N hydrogen bond occurs between the NH group of the triazole ring and the N atom of the thio-cyanate bridging ligand. A (101) sheet structure arises from inter-chain S⋯N short contacts [3.239 (3) Å] involving the thio-cyanate S atom and the triazole-ring N atom and possible very weak π-π stacking [centroid-centroid separation = 4.0762 (18) Å] between the triazole rings.

Clauraila E from the roots of Clausena harmandiana and antifungal activity against Pythium insidiosum.

A new carbazole alkaloid named clauraila E (1) together with 8 known compounds were isolated from the methanol extract of the roots of Clausena harmandiana. All compounds were evaluated for antifungal activity against Pythium insidiosum using disc diffusion assay. Pythium insidiosum is a fungus-like microorganism, for which antifungals available now are not effective. It was found that compounds 3, 6, 7 and 9 could inhibit the mycelia growth of P. insidiosum. The results show convincingly that they may be lead to compounds for the development of probiotic or novel antifungal drugs.