C2/c Space Group (c + space_group)

Distribution by Scientific Domains
Chemistry90%

Kinds of C2/c Space Group

  • monoclinic c space group
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    Selected Abstracts

    Hybrid Organic/Inorganic Supramolecular Conductors D2[Au(CN)4] [D = Diiodo(ethylenedichalcogeno)tetrachalcogenofulvalene], Including a New Ambient Pressure Superconductor

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 30 2007
    Tatsuro Imakubo
    Abstract Five diiodo(ethylenedichalcogeno)tetrachalcogenofulvalenes, DIEDSS {2-(5,6-dihydro[1,3]diselenolo[4,5- b][1,4]diselenin-2-ylidene)-4,5-diiodo-1,3-dithiole}, DIET-STF {2-(4,5-diiodo-1,3-diselenol-2-ylidene)-5,6-dihydro[1,3]dithiolo[4,5- b][1,4]dithiine}, DIEDS-STF {2-(4,5-diiodo-1,3-diselenol-2-ylidene)-5,6-dihydro[1,4]diselenino[2,3- d][1,3]dithiole}, DIETSe {2-(4,5-diiodo-1,3-diselenol-2-ylidene)-5,6-dihydro[1,3]diselenolo[4,5- b][1,4]dithiine}, and DIEDSSe {2-(4,5-diiodo-1,3-diselenol-2-ylidene)-5,6-dihydro[1,3]diselenolo[4,5- b][1,4]diselenine},have been synthesized without the use of the highly toxic reagent CSe2, and their Au(CN)4 salts have been prepared by electrochemical oxidation. Characteristic I···N iodine bonds are constructed in all crystals, and their packing motifs are classified into two groups by the difference in the space group symmetry. The salt of DIEDSS crystallizes in the monoclinic C2/c space group and a novel helical supramolecular architecture is constructed by the strong and directional I···N iodine bond. On the other hand, the rest of the four salts crystallize in the triclinic P space group and their donor packing motifs belong to the so-called ,-type. Conducting properties of the ,-type salts strongly depend on the number and positions of the selenium atoms on the donor molecule. The salts based on the diselenadithiafulvalene (DSDTF) derivatives, DIET-STF and DIEDS-STF, show metal,semiconductor transition and the salt of fully selenated ,-donor DIEDSSe shows stable metallic behavior down to 1.6 K. On the other hand, (DIETSe)2[Au(CN)4] is semimetallic down to low temperature and the superconducting transition occurs at around 2 K (onset).(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

    Synthesis, Crystal Structure, and Second-Order Nonlinear Optical Properties of Ruthenium(II) Complexes with Substituted Bipyridine and Phenylpyridine Ligands

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2006
    Laurence Labat
    Abstract Two new ruthenium(II) complexes of formula [Ru(bpy)2(L1)][PF6] and [Ru(bpy)2(L2)][PF6]2 are reported. HL1 is a (nitrophenyl)ethenyl-substituted phenylpyridine ligand, and L2 is the bipyridine analogue of HL1. The X-ray crystal structure of [Ru(bpy)2(L1)][PF6] has been solved, and the compound is found to crystallize in the monoclinic C2/c space group. The electronic spectrum of the cyclometalated derivative [Ru(bpy)2(L1)][PF6] exhibits a low-lying transition that is red-shifted from 454 to 546 nm relative to that of the parent bipyridine-based complex, which reveals an important charge-transfer character. To support this assumption, the nonlinear optical properties were investigated by the hyper-Rayleigh scattering technique and indicate a molecular static hyperpolarizability (,0) equal to 230,×,10,30 cm5,esu,1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]

    New Molecular Charge-Transfer Salts of TM-TTF and BMDT-TTF with Thiocyanate and Selenocyanate Complex Anions [TMTTF = Tetramethyltetrathiafulvalene; BMDT-TTF = Bis(methylenedithio)tetrathiafulvalene]

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 4 2003
    Marta Mas-Torrent
    Abstract Three new charge-transfer salts of tetrathiafulvalene (TTF)-based donors with thiocyanato- or selenocyanato-metal complex anions have been synthesised. The salts isolated were [BMDT-TTF]4[Cr(NCS)6] (1), [TM-TTF]4[Cr(NCS)6]·2CH3CN (2) and [TM-TTF]4[Cr(NCSe)6]·2CH3CN (3) [BMDT-TTF = bis(methylenedithio)tetrathiafulvalene and TM-TTF = tetramethyltetrathiafulvalene]. Single crystals of compound 1 crystallise in the monoclinic C2/c space group with a = 37.286(3), b = 10.0539(6), c = 21.069(2) Å, , = 124.348(4)°, V = 6520.9(9) Å3 and Z = 4. Compound 3 was also suitable for an X-ray diffraction study, however the anionic part, [Cr(NCSe)6], was highly disordered and the best solution gave a final R factor of 16.4%. A solution was found for the monoclinic space group C2/m with a = 13.787(3), b = 19.507(3), c = 14.735(5) Å, , = 102.90(3)°, V = 3862.9(17) Å3 and Z = 2. For compound 1 there are several S···S close atomic contacts between the donors and acceptors, but there is no discernible magnetic exchange between ions. Such an interaction was previously observed in related salts such as [TTF][Cr(NCS)4(phenanthroline)2] and [donor][M(NCS)4(isoquinoline)2] [M = Cr, Fe and donor = TTF, BEDT-TTF or TM-TTF (tetramethyltetrathiafulvalene)]. Compounds 1 to 3 are all paramagnetic semiconductors in which the magnetic susceptibility is dominated by the Cr-containing anions. The structure-function relationship, along with a comparison with related compounds, indicates that there is no long-range magnetic order because there are no ,-stacking interactions between donor and acceptor; these types of interactions are seen in all of the bulk magnets of this type in which the donor spin is magnetically coupled to the anion. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    Mono- and bis-tolylterpyridine iridium(III) complexes

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010
    Lindsay M. Hinkle
    The first structure report of trichlorido[4,-(p -tolyl)-2,2,:6,,2,,-terpyridine]iridium(III) dimethyl sulfoxide solvate, [IrCl3(C22H17N3)]·C2H6OS, (I), is presented, along with a higher-symmetry setting of previously reported bis[4,-(p -tolyl)-2,2,:6,,2,,-terpyridine]iridium(III) tris(hexafluoridophosphate) acetonitrile disolvate, [Ir(C22H17N3)2](PF6)3·2C2H3N, (II) [Yoshikawa, Yamabe, Kanehisa, Kai, Takashima & Tsukahara (2007). Eur. J. Inorg. Chem. pp. 1911,1919]. For (I), the data were collected with synchrotron radiation and the dimethyl sulfoxide solvent molecule is disordered over three positions, one of which is an inversion center. The previously reported structure of (II) is presented in the more appropriate C2/c space group. The iridium complex and one PF6, anion lie on twofold axes in this structure, making half of the molecule unique. [source]

    Three-dimensional networks in bis(imidazolium) 2,2,-dithiodibenzoate and 4-methylimidazolium 2-[(2-carboxyphenyl)disulfanyl]benzoate

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009
    Linheng Wei
    Cocrystallization of imidazole or 4-methylimidazole with 2,2,-dithiodibenzoic acid from methanol solution yields the title 2:1 and 1:1 organic salts, 2C3H5N2+·C14H10O4S22,, (I), and C4H7N2+·C14H10O4S2,, (II), respectively. Compound (I) crystallizes in the monoclinic C2/c space group with the mid-point of the S,S bond lying on a twofold axis. The component ions in (I) are linked by intermolecular N,H...O hydrogen bonds to form a two-dimensional network, which is further linked by C,H...O hydrogen bonds into a three-dimensional network. In contrast, by means of N,H...O, N,H...S and O,H...O hydrogen bonds, the component ions in (II) are linked into a tape and adjacent tapes are further linked by ,,,, C,H...O and C,H..., interactions, resulting in a three-dimensional network. [source]

    X-ray structure and density functional theory studies of an unexpected product: trans -bis{2-[(2-cyanoethyl)iminomethyl]phenolato}copper(II)

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2009
    Maddalena Corsini
    The title compound, [Cu(C10H9N2O)2] or [CuII(CYMB)2], (I), was obtained in an attempt to reduce trans -bis(2-{[3,5-bis(trifluoromethyl)phenyl]iminomethyl}phenolato)copper(II), [Cu(TIMB)2], (II), with bis(pentamethylcyclopentadienyl)cobalt(II) [decamethylcobaltocene, Cp*2Co, (III)]. The molecular structure of (I) has the CuII centre located on an inversion centre of the C2/c space group. A density functional theory (DFT) analysis at the B3LYP/Lanl2dz(CuF);6-31G**(CHNO) level performed in order to optimize the structures of the free ligands CYMB, and TIMB,, and the metal complexes [CuI/II(CYMB)2],/0 and [CuI/II(TIMB)2],/0, reproduced well the X-ray diffraction structure and allowed us to infer the insertion of the cyanomethide anion on the 3,5-bis(trifluoromethyl)phenyl system from an evaluation of the Mulliken atomic charges and the electronic energies. [source]

    A new pillared lithium bismuth phosphate, LiBi7.37P3O19, with elliptical channels

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2007
    Nachiappan Arumugam
    The structure of a new lithium bismuth phosphate, LiBi7.37P3O19, consists of infinite OBi4 edge-sharing tetrahedral chains in the ac plane, which form Bi2O2 layers parallel to the b axis. They are sandwiched between PO4 tetrahedral and Bi polyhedral layers. The PO4,Bi,PO4 layers are bridged by columns formed by one Bi polyhedron flanked on each side by LiO4 tetrahedra. This bridging Bi atom lies on a twofold axis, special position 4e of the C2/c space group. This arrangement creates pillared open elliptical channels parallel to [010]. [source]

    Na1.50Mn2.48Al0.85(PO4)3, a new synthetic alluaudite-type compound

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2006
    Frédéric Hatert
    The first hydro­thermal synthesis of an Al-rich alluaudite-type compound, namely disodium dimanganese aluminium tris­(phosphate), which has been obtained at 1073,K and 0.1,GPa starting from the composition Na2Mn2Al(PO4)3, is reported. The crystal structure, which has been refined in the monoclinic C2/c space group, is identical to that of natural alluaudite. The structure consists of kinked chains of edge-sharing M1 and M2 octa­hedra, which contain Mn2+ and Al3+ ions. The chains are stacked parallel to {101} and are connected in the b direction by the P1 and P2 tetra­hedra. These inter­connected chains produce channels parallel to c, which contain the large A1 and A2, sites occupied by Na+ and Mn2+ ions. [source]

    Crystal Structures and Magnetic Properties of Nitronyl Nitroxide Radicals

    HELVETICA CHIMICA ACTA, Issue 4 2003
    Alexander Zakrassov
    The crystal structures and magnetic properties of the nitronyl nitroxide radicals 4,5-dihydro-4,4,5,5-tetramethyl-3-oxido(1H -imidazol-1-yloxyl) (1), 4,5-dihydro-2,4,4,5,5-pentamethyl-3-oxido(1H -imidazol-1-yloxyl) (2), 2-(4-chlorophenyl)-4,5-dihydro-4,4,5,5-tetramethyl-3-oxido(1H -imidazol-1-yloxyl) (3), and 4,5-dihydro-2-(2-hydroxy-5-nitrophenyl)-4,4,5,5-tetramethyl-3-oxido(1H -imidazol-1-yloxyl) (4) are reported. Compound 1 has two polymorphic forms: the , phase is monoclinic (P21/n space group), with a single molecule in the asymmetric unit, and the , phase is monoclinic (P21/c space group), with four molecules in the asymmetric unit. In the two polymorphs, the molecules are arranged in dimers formed by hydrogen bonds of the type CH,,,ON. The crystal structure of 3 contains layers of antiparallel ribbons of molecules. Compound 4 crystallizes with solvent molecules, and an intramolecular hydrogen bond is formed between the 2-OH group of the phenyl ring and the nitroxide O-atom. Compound 4 also loses the two O-atoms of the nitroxide moiety upon heating to 90°. Magnetic measurements showed that both , and , polymorphs of 1 exhibit antiferromagnetic coupling. The best fit to the experimental data was obtained using BleanyBower's singlet-triplet model (H=,2JSaSb): J=,11.2,K for the , phase and J=,15.0,K for the , phase. Compounds 3 and 4 show no evidence for spin coupling. [source]

    X-ray and 13C solid-state NMR studies of N -benzoyl-phenylalanine

    CHEMICAL BIOLOGY & DRUG DESIGN, Issue 4 2000
    M.J. Potrzebowski
    Abstract: A crystalline sample of N -benzoyl- dl -phenylalanine 1 and a polycrystalline sample of N -benzoyl- l -phenylalanine 2 were studied using 13C high-resolution solid-state NMR spectroscopy. The X-ray structure of the dl form was established. Sample 1 crystallizes in a monoclinic form with a P21/c space group, a = 11.338(1) Å, b = 9.185(1) Å, c = 14.096(2) Å, ,,= 107.53(3)°, V = 1400(3) Å3, Z = 4 and R = 0.053. The principal elements of the 13C chemical shift tensors ,ii for 1 and 2, selectively 13C (99%) labeled at the carboxyl groups were calculated. On the basis of 13C ,ii analysis the hydrogen bonding pattern for sample 2 was deduced. Enriched samples were used to establish the intermolecular distance between chemically equivalent nuclei for 1 and spatial proximity in heterogeneous domain for 2, employing the ODESSA pulse sequence. The consistence of the complementary approach covering X-ray data, analysis of the 13C ,ii parameters and ODESSA results is revealed. [source]

    Nitrogen-rich 6-(3,5-Dimethylpyrazol-1-yl)-3-(2,4,6-trinitro-anilino)-1,2,4,5-tetrazin: Synthesis, Crystal Structure and Thermal Property

    CHINESE JOURNAL OF CHEMISTRY, Issue 10 2007
    Wan-Long PAN
    Abstract 6-(3,5-Dimethylpyrazol-1-yl)-3-(2,4,6-trinitroanilino)-1,2,4,5-tetrazin (1) has been synthesized and characterized by 1H NMR, MS, elemental analysis, infrared spectra and thermal analyses. The crystal structure was determined by X-ray diffraction method. 1 is crystallized in P21/c space group of monoclinic crystal system, and exhibits good physical properties, such as high densities (>1.55 g·cm,3) and good thermal stabilities (Td>220 °C). The intrermolecular hydrogen bonds construct the P - and M -helices from organic molecules and may contribute to the high melting points. [source]