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Solvate
Kinds of Solvate Terms modified by Solvate Selected AbstractsStructure of Hexakis (imidazole) nickel (II) Nitrate Water Solvate: [Ni(Im)6](NO3)2 -4H2OCHINESE JOURNAL OF CHEMISTRY, Issue 10 2002Fang-Fang Jian Abstract Crystal structure of the title compound, [Ni(Im)6] (NO3)2·4H2O (Im = imidazole), was determined by X-ray crystallographic analysis. The crystal structure consists of discrete Ni(Im)26+ cation, NO,3 anion and four uncoordinated water molecules. It crystallizes in the hexagonal system, space group P63, with lattice parameters a = b = 0.9003(2) nm, c = 2.1034(4) nm, and Z = 2. The Ni(II) ion is centro- symmetric octahedron geometry with the NiN6 core. Six imidazole molecules are coordinated to each nickel (II) atom through its tertiary nitrogen atom. The short and long bond distances of Ni-N are 0.2059(6) and 0.2204(7) nm, respectively. In the solid state, [Ni(Im)6]2+, H2O moieties and nitrate anions form the three dimensional hydrogen bonds network which stabitizes the crystal structure. [source] Thermal, phase transition and spectral studies in erythromycin pseudopolymorphs: dihydrate and acetone solvateCRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2006Zhanzhong Wang Abstract The thermal, phase transition and spectral studies of erythromycin A dihydrate and acetone solvate were performed by Differential Scanning calorimetry (DSC), Thermo Gravimetry (TG-DTA), X-Ray Powder Diffraction (XRPD) and Fourier Transform Infra-Red (FTIR) spectrum. The non-thermal kinetic analysis of erythromycin A dihydrate was carried out by DSC at different heating rates in dynamic nitrogen atmosphere. The result showed that heating rate has substantial influence on the thermal behavior of erythromycin dihydrate. The Arrhenius parameters were estimated according to the Kissinger method. Corresponding to dehydration of dihydrate, melting of dehydrated dihydrate, phase transition from dehydrated dihydrate to anhydrate, and melting of anhydrate, the calculated activation energy were 39.60, 269.85, 261.23, and 582.16 kJmol,1, the pre-exponential factors were 3.46 × 103, 8.06 × 1032, 9.23 × 1030, and 7.29 × 1063 s,1, respectively. Ozawa method was used to compare activation energy values calculated by Kissinger method. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] 1,3,5-Triazapentadiene Nickel(II) Complexes Derived from a Ketoxime-Mediated Single-Pot Transformation of NitrilesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 16 2010Maximilian N. Kopylovich Abstract A series of cationic (2+) [Ni{HN=C(R)NHC(R)=NH}2](X)2 {R = 4-(Cl)C6H4 (1), 3-(NC)C6H4 (3), 4-(NC)C6H4 (4) and Me (7); X = Cl, (1, 3, 4) or MeCOO,·H2O (7)} and neutral [Ni{HN=C(R)NC(R)=NH}2](solvate) {R = 3-(Cl)-4-py (2), 3-py (5) and 4-py (6); solvate = MeOH and/or H2O; py = pyridyl} N,N -chelating bis(1,3,5-triazapentadiene/ato)nickel(II) [Ni(tap)2]2+/0 complexes has been easily generated by a ketoxime-mediated single-pot reaction of a nickel(II) salt [NiCl2·2H2O or Ni(MeCOO)2·4H2O] with 4-chlorobenzonitrile, isophthalonitrile, terephthalonitrile, acetonitrile, 2-chloro-4-cyanopyridine, 3-cyanopyridine or 4-cyanopyridine, respectively. The obtained compounds have been characterized by IR, 1H and 13C{1H} NMR spectroscopy, FAB-MS(+) or ESI-MS(+), elemental analyses and single-crystal X-ray diffraction [for 7 and solvated mono- {1a·(Me2CO)0.33·(MeOH)0.67} and bis-deprotonated (2b·2Me2CO, 4b·CHCl3, 5b·Me2CO and 6b·MeOH) products, formed upon recrystallization of 1, 2, 4, 5 and 6, respectively]. The crystal structures of all compounds bear similar monomeric Ni(tap)2 units with a nearly square-planar geometry. In addition, the structure of 7 features the formation of infinite 1D zig-zag water,acetate chains {[(H2O)2(MeCOO)2]2,}n, which multiply interact with the [Ni(tap)2]2+ cations to generate a 2D hydrogen-bonded supramolecular assembly. [source] Synthesis and Structure Determination of Selenium(IV) CyanidesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 30 2008Stefanie Fritz Abstract The reaction of SeF4 with Me3SiCN did not result in thepreparation of the designated Se(CN)4 but Se(CN)F3 and Se(CN)2F2 were obtained as first known selenium(IV)cyanide compounds and characterized by their NMR spectra. Se(CN)2F2 was crystallized as 1,2-dimethoxyethane solvate as well as the corresponding tellurium compound Te(CN)2F2 with very similar structures. NMR spectroscopic data of some more miscellaneous tellurium cyanides and the crystal structures of solvates of Se(CN)2 and oxygen-bridged TeO(CN)2 are presented. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Sodium Hydro(isothiocyanato)borates: Synthesis and StructuresEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 5 2004Heinrich Nöth Abstract Sodium thiocyanate reacts in THF solution with 18-crown-6 to give the molecular compound Na(18-crown-6)(THF)NCS (3) with the N atom of the NCS anion oriented towards Na+. The same reaction with 15-crown-5 yields the ion pair Na(15-crown-5)NCS (4). In contrast, Na(NCS)(py)4, obtained by treating a solution of Na(H3BNCS) in THF with pyridine, yields Na(py)4(NCS) (5), which has a chain structure with hexacoordinate Na atoms coordinated to five N atoms and an S atom. Na(NCS) in THF adds 1 equiv. of BH3 to give Na(H3BNCS)·nTHF. Addition of 18-crown-6 to this solution yields crystals of the salt [Na(18-crown-6)(THF)2][H3BNCS] (1), as shown by X-ray crystallography. Both the cation and the anion show site disorder. However, when 15-crown-5 is used for complexation, the salt [Na(15-crown-5)(THF)][H3BNCS] (2) can be isolated. Its anion shows an almost linear B,N,C,S unit. Only a mixture of (catecholato)(isothiocyanato)borates results on treating Na(NCS) in THF with catecholborane. However, the borate Na[catB(NCS)2] is readily formed by adding Na(NCS) to B -(isothiocyanato)catecholborane. Single crystals of this compound were obtained as the salt [Na(18-crown-6)(THF)2][catB(NCS)2] (6). On the other hand, the reaction of Na(NCS) with 9-borabicyclo[3.3.1]nonane (9-BBN) in THF yields Na[(9-BBN)NCS)]·nTHF, and, on addition of 18-crown-6, the complex [Na(18-crown-6)(THF)2][(9-BBN)NCS] was isolated. Suitable crystals for X-ray structure determination were, however, only obtained by crystallization from tetrahydropyran. This solvate has the rather unusual structure [Na(18-crown-6)(thp)2][{(9-BBN)NCS}2Na(thp)4] (8). The sodiate anion has an Na atom coordinated by two S and four O atoms. DFT calculations support these experimental results: The (isothiocyanato)borates are more stable than the thiocyanato isomers. For the latter a bent structure of the B,S,C,N unit with a B,S,C bond angle of 105.7° is predicted. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Complexation and Dynamic Switching Properties of Fluorophore-Appended Resorcin[4]arene CavitandsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 5 2010Laura D. Shirtcliff Abstract Fluorophore-appended resorcin[4]arene-based cavitands having pyrene (2) and anthracene (3) moieties attached to the rims were prepared by short synthetic routes. Both undergo reversible temperature- and acid- (CF3COOD) induced vase,,,kite switching as evidenced by 1H NMR spectroscopy. The 1H NMR spectra also suggest that suitably sized solvents, such as [D8]toluene, efficiently solvate the cavity, reducing the conformational flexibility. In [D12]mesitylene, both cavitands undergo remarkably stable host-guest inclusion complexation with cycloalkanes. The larger cavity of 3 preferentially hosts cyclohexane, whereas the smaller cavity of 2 forms the most stable complex with cyclopentane. The propensity for the cavitands to facilitate ,,, stacking between the chromophores was confirmed by both 1H NMR and fluorescence spectroscopy. The interchromophoric interaction is strongly solvent-dependent: ,,, stacking between the pyrene moieties of 2 is not as efficient in [D8]toluene, as it solvates the inner cavity and prevents the two chromophores from approaching each other. Fluorescence studies revealed an unexpectedly large conformational flexibility of the cavitand structures both in the vase and kite forms, which was further confirmed by molecular dynamics simulations. Excimer formation is most preferred in [D12]mesitylene when the cavities are empty, whereas efficient solvation or guest binding in the interior spaces reduces the propensity for excimer formation. The observed high conformational flexibility of the cavitands in solution explains previous differences from the behavior of related systems in the solid state. This study shows that the rigid, perfect vase and kite geometries found for bridged resorcin[4]arene cavitands in the solid state are largely a result of crystal packing effects and that the conformational flexibility of the structures in solution is rather high. [source] Solid-state properties of warfarin sodium 2-propanol solvateJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 11 2004Agam R. Sheth Abstract The goal of the present work was to understand the effect of relative humidity (RH) and temperature on the molecular structure, crystal structure, and physical properties of warfarin sodium 2-propanol solvate (W). After previous determination of the crystal structure of W, which corresponds to a 1:1 2-propanol solvate, the present work shows that W has a critical RH (60%,<,RH0,,,68%), below which minimal uptake of water occurs, due to surface adsorption, but above which gradual and continuous uptake of water occurs, due to deliquescence. Deliquescence begins at the surface and proceeds inward into the bulk of the crystal. Single crystal X-ray diffractometry indicates no change in the crystal and molecular structure of W during the initial stages of deliquescence. Studies of the unit cell and volume computations of W show that water can neither find space to enter the crystal lattice, nor can replace 2-propanol. Thus, water does not exchange with 2-propanol within the lattice, contrary to previous reports. Storage of single crystals of W at 120°C for 23 h produces shrinkage cracks along the needle (b) axis, which are interpreted as a reduction in d -spacing of the 00l planes. Thus, under thermal stress, W crystals undergo amorphization with concurrent loss of 2-propanol, which may proceed via an intermediate crystalline phase. The phase changes of W, which depend on RH and temperature, are explained at the molecular level. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:2669,2680, 2004 [source] Polymorphism of racemic felodipine and the unusual series of solid solutions in the binary system of its enantiomersJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2001Judith M. Rollinger Abstract The aim of this study was to investigate the binary phase diagram and the polymorphism and pseudopolymorphism of racemic and enantiomeric felodipine, including their spectroscopic and thermodynamic properties. Different crystal forms were obtained by crystallization from solvents or from the annealed melt and investigated by thermal analysis (hot stage microscopy, differential scanning calorimetry, thermogravimetric analysis), spectroscopic methods (Fourier transform infrared,and Fourier transform,Raman spectroscopy), and X-ray powder diffractometry. The binary melting phase diagram was constructed based on thermoanalytical investigations of quantitative mixtures of (+)- and (±)-felodipine. Two polymorphic forms of racemic felodipine, mod. I (mp, ,145°C) and mod. II (mp, ,135°C), as well as an acetone solvate (SAc,) were characterized. Melting equilibria of felodipine crystal forms decrease due to thermal decomposition. Enantiomeric felodipine was found to be dimorphic (En-mod. I: mp, ,144°C; En-mod. II: mp, ,133°C). Evaluation of the binary system of (+)- and (,)-felodipine results in the formation of a continuous series of mixed crystals between the thermodynamically stable and higher melting modifications, mod. I and En-mod. I. Their unusual curve course, termed as Roozeboom Type 2 b, passes through a maximum in the racemic mixture and is flanked by a minimum at 20% and at 80% (+)-felodipine. From the thermodynamic parameters, racemic mod. I and II are monotropically related. In contrast to SAc, the thermodynamically unstable mod. II shows a considerable kinetic stability. Because its crystallization is badly reproducible, the use of mod. II is not advisable for processing. However, desolvation of SAc leads to a profitable crystal shape of mod. I, representing a pseudoracemate by definition. © 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:949,959, 2001 [source] Investigation of structure and dynamics in the sodium metallocenes CpNa and CpNa·THF via solid-state NMR, X-ray diffraction and computational modellingMAGNETIC RESONANCE IN CHEMISTRY, Issue S1 2007Cory M. Widdifield Abstract Solid-state 23Na NMR spectra of two organometallic complexes, cyclopentadienylsodium (CpNa) and the tetrahydrofuran (THF) solvate of CpNa (CpNa·THF), are presented. Analytical simulations of experimental spectra and calculated 23Na electric-field gradient (EFG) tensors confirm that both complexes are present in microcrystalline samples of CpNa recrystallized from THF. For the solvate, 23Na NMR experiments at 9.4 T and 11.7 T elucidate sodium chemical shielding (CS) tensor parameters, and establish that the EFG and CS tensor frames are non-coincident. Single-crystal X-ray diffraction (XRD) experiments are used to determine the crystal structure of CpNa·THF: Cmca (a = 9.3242(15) Å, b = 20.611(3) Å, c = 9.8236(14) Å, , = , = , = 90° , V = 1887.9(5)Å3, Z = 8). For CpNa, 23Na NMR data acquired at multiple field strengths establish sodium CS tensor parameters more precisely than in previous reports. Variable-temperature (VT) powder XRD (pXRD) experiments determine the temperature dependence of the CpNa unit cell parameters. The combination of 23Na quadrupolar NMR parameters, pXRD data and calculations of 23Na EFG tensors is used to examine various models of dynamic motion in the solid state. It is proposed that the sodium atom in CpNa undergoes an anisotropic, temperature-dependent, low frequency motion within the ab crystallographic plane, in contrast with previous models. Copyright © 2007 John Wiley & Sons, Ltd. [source] Structures of six industrial benzimidazolone pigments from laboratory powder diffraction dataACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2009Jacco Van De Streek The crystal structures of six industrially produced benzimidazolone pigments [Pigment Orange 36 (, phase), Pigment Orange 62, Pigment Yellow 151, Pigment Yellow 154 (, phase), Pigment Yellow 181 (, phase) and Pigment Yellow 194] were determined from laboratory X-ray powder diffraction data by means of real-space methods using the programs DASH and MRIA, respectively. Subsequent Rietveld refinements were carried out with TOPAS. The crystal phases correspond to those produced industrially. Additionally, the crystal structures of the non-commercial compound `BIRZIL' (a chloro derivative of Pigment Yellow 194) and of a dimethylsulfoxide solvate of Pigment Yellow 154 were determined by single-crystal structure analyses. All eight crystal structures are different; the six industrial pigments even exhibit five different hydrogen-bond topologies. Apparently, the good application properties of the benzimidazolone pigments are not the result of one specific hydrogen-bonding pattern, but are the result of a combination of efficient molecular packing and strong intermolecular hydrogen bonds. [source] Structure determination of seven phases and solvates of Pigment Yellow 183 and Pigment Yellow 191 from X-ray powder and single-crystal dataACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2009Svetlana N. Ivashevskaya The crystal structures of two industrially produced laked yellow pigments, Pigment Yellow 183 [P.Y. 183, Ca(C16H10Cl2N4O7S2), , phase] and Pigment Yellow 191 [P.Y. 191, Ca(C17H13ClN4O7S2), , and , phases], were determined from laboratory X-ray powder diffraction data. The coordinates of the molecular fragments of the crystal structures were found by means of real-space methods (simulated annealing) with the program DASH. The coordinates of the calcium ions and the water molecules were determined by combining real-space methods (DASH and MRIA) and repeated Rietveld refinements (TOPAS) of the partially finished crystal structures. TOPAS was also used for the final Rietveld refinements. The crystal structure of ,-P.Y. 183 was determined from single-crystal data. The , phases of the two pigments are isostructural, whereas the , phases are not. All four phases exhibit a double-layer structure, built from nonpolar layers containing the C/N backbone and polar layers containing the calcium ions, sulfonate groups and water molecules. Furthermore, the crystal structures of an N,N -dimethylformamide solvate of P.Y. 183, and of P.Y. 191 solvates with N,N -dimethylformamide and N,N -dimethylacetamide were determined by single-crystal X-ray analysis. [source] Methyl ,- d -galactopyranosyl-(1,4)-,- d -allopyranoside tetrahydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2010Wenhui Zhang The title compound, C13H24O11·4H2O, (I), crystallized from water, has an internal glycosidic linkage conformation having ,, (O5Gal,C1Gal,O1Gal,C4All) = ,96.40,(12)° and ,, (C1Gal,O1Gal,C4All,C5All) = ,160.93,(10)°, where ring-atom numbering conforms to the convention in which C1 denotes the anomeric C atom, C5 the ring atom bearing the exocyclic hydroxymethyl group, and C6 the exocyclic hydroxymethyl (CH2OH) C atom in the ,Galp and ,Allp residues. Internal linkage conformations in the crystal structures of the structurally related disaccharides methyl ,-lactoside [methyl ,- d -galactopyranosyl-(1,4)-,- d -glucopyranoside] methanol solvate [Stenutz, Shang & Serianni (1999). Acta Cryst. C55, 1719,1721], (II), and methyl ,-cellobioside [methyl ,- d -glucopyranosyl-(1,4)-,- d -glucopyranoside] methanol solvate [Ham & Williams (1970). Acta Cryst. B26, 1373,1383], (III), are characterized by ,, = ,88.4,(2)° and ,, = ,161.3,(2)°, and ,, = ,91.1° and ,, = ,160.7°, respectively. Inter-residue hydrogen bonding is observed between O3Glc and O5Gal/Glc in the crystal structures of (II) and (III), suggesting a role in determining their preferred linkage conformations. An analogous inter-residue hydrogen bond does not exist in (I) due to the axial orientation of O3All, yet its internal linkage conformation is very similar to those of (II) and (III). [source] Coordination and hydrogen-bonding assemblies in hybrid reaction products between 5,10,15,20-tetra-4-pyridylporphyrin and dysprosium trinitrate hexahydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010Sophia Lipstman Reactions of the title free-base porphyrin compound (TPyP) with dysprosium trinitrate hexahydrate in different crystallization environments yielded two solid products, viz. [,-5,15-bis(pyridin-1-ium-4-yl)-10,20-di-4-pyridylporphyrin]bis[aquatetranitratodysprosium(III)] benzene solvate, [Dy2(NO3)8(C40H28N8)(H2O)2]·C6H6, (I), and 5,10,15,20-tetrakis(pyridin-1-ium-4-yl)porphyrin pentaaquadinitratodysprosate(III) pentanitrate diethanol solvate dihydrate, (C40H30N8)[Dy(NO3)2(H2O)5](NO3)5·2C2H6O·2H2O, (II). Compound (I) represents a 2:1 metal,porphyrin coordinated complex, which lies across a centre of inversion. Two trans -related pyridyl groups are involved in Dy coordination. The two other pyridyl substituents are protonated and involved in intermolecular hydrogen bonding along with the metal-coordinated water and nitrate ligands. Compound (II) represents an extended hydrogen-bonded assembly between the tetrakis(pyridin-1-ium-4-yl)porphyrin tetracation, the [Dy(NO3)2(H2O)5]+ cation and the free nitrate ions, as well as the ethanol and water solvent molecules. This report provides the first structural characterization of the exocyclic dysprosium complex with tetrapyridylporphyrin. It also demonstrates that charge balance can be readily achieved by protonation of the peripheral pyridyl functions, which then enhances their capacity in hydrogen bonding as H-atom donors rather than H-atom acceptors. [source] Structural comparison of three N -(4-halogenophenyl)- N,-[1-(2-pyridyl)ethylidene]hydrazine hydrochloridesACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010Julia Heilmann-Brohl 2-{1-[(4-Chloroanilino)methylidene]ethyl}pyridinium chloride methanol solvate, C13H13ClN3+·Cl,·CH3OH, (I), crystallizes as discrete cations and anions, with one molecule of methanol as solvent in the asymmetric unit. The N,C,C,N torsion angle in the cation indicates a cis conformation. The cations are located parallel to the (02) plane and are connected through hydrogen bonds by a methanol solvent molecule and a chloride anion, forming zigzag chains in the direction of the b axis. The crystal structure of 2-{1-[(4-fluoroanilino)methylidene]ethyl}pyridinium chloride, C13H13FN3+·Cl,, (II), contains just one anion and one cation in the asymmetric unit but no solvent. In contrast with (I), the N,C,C,N torsion angle in the cation corresponds with a trans conformation. The cations are located parallel to the (100) plane and are connected by hydrogen bonds to the chloride anions, forming zigzag chains in the direction of the b axis. In addition, the crystal packing is stabilized by weak ,,, interactions between the pyridinium and benzene rings. The crystal of (II) is a nonmerohedral monoclinic twin which emulates an orthorhombic diffraction pattern. Twinning occurs via a twofold rotation about the c axis and the fractional contribution of the minor twin component refined to 0.324,(3). 2-{1-[(4-Fluoroanilino)methylidene]ethyl}pyridinium chloride methanol disolvate, C13H13FN3+·Cl,·2CH3OH, (III), is a pseudopolymorph of (II). It crystallizes with two anions, two cations and four molecules of methanol in the asymmetric unit. Two symmetry-equivalent cations are connected by hydrogen bonds to a chloride anion and a methanol solvent molecule, forming a centrosymmetric dimer. A further methanol molecule is hydrogen bonded to each chloride anion. These aggregates are connected by C,H...O contacts to form infinite chains. It is remarkable that the geometric structures of two compounds having two different formula units in their asymmetric units are essentially the same. [source] 5-(3,4-Dimethoxybenzyl)-7-isopropyl-1,3,5-triazepane-2,6-dione acetonitrile solvate refined using a multipolar atom modelACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2010Krzysztof Ejsmont The crystal structure of the title compound, C16H23N3O4·CH3CN, was refined using a multipolar atom model transferred from an experimental electron-density database. The refinement showed some improvement in crystallographic statistical indices compared with the independent atom model. The triazepane ring adopts a twist-boat conformation. In the crystal structure, the molecule forms intermolecular contacts with 14 different neighbours. There are two N,H...O and one C,H...O intermolecular hydrogen bond. [source] A synchrotron study of (2R,5,S)-5,-benzyl-5-bromo-6-methoxyspiro[indane-2,2,-piperazine]-3,,6,-dione dimethylformamide solvateACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2010Gary S. Nichol Synchrotron radiation was used to study the structure of the title compound, C20H19BrN2O3·C3H7NO, which was obtained as fine fragile needle-shaped crystals by recrystallization from dimethylformamide (DMF), one molecule of which is incorporated per asymmetric unit into the crystal. The compound adopts a compact closed conformation with the orientation of the benzyl group such that the aryl ring is positioned over the piperazinedione ring, resulting in a Cspiro...Ctrans,C,CPh pseudo-torsion angle of ,3.3,(3)°. The five-membered ring is present in an expected envelope conformation and the six-membered piperazinedione ring adopts a less puckered boat-like conformation. Reciprocal amide-to-amide hydrogen bonding between adjacent piperazinedione rings and C,H...O interactions involving DMF molecules propagate in the crystal as a thick ribbon in the a -axis direction. [source] [,-4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene]bis[(trifluoroacetato)gold(I)] and its dichloromethane 0.58-solvateACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2010Tünde Tunyogi The dinuclear AuI complex containing the 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (xantphos) ligand and trifluoroacetate anions exists in a solvent-free form, [,-4,5-bis(diphenylphosphino)-9,9-dimethylxanthene]bis[(trifluoroacetato)gold(I)], [Au2(C2F3O2)2(C39H32OP2)], (I), and as a dichloromethane solvate, [Au2(C2F3O2)2(C39H32OP2)]·0.58CH2Cl2, (II). The trifluoroacetate anions are coordinated to the AuI centres bridged by the xantphos ligand in both compounds. The AuI atoms are in distorted linear coordination environments in both compounds. The phosphine substituents are in a syn arrangement in the xantphos ligand, which facilitates the formation of short aurophilic Au...Au interactions of 2.8966,(8),Å in (I) and 2.9439,(6),Å in (II). [source] C,H..., interactions in cocrystals of bis(trimethylsilyl)acetylene and diphenylacetylene with benzeneACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010Frank Meyer-Wegner We present here the crystal structures of two acetylene derivatives cocrystallized with benzene, namely bis(trimethylsilyl)acetylene benzene solvate, C8H18Si2·C6H6, (I), and diphenylacetylene benzene solvate, C14H10·C6H6, (II). In (I), both molecules belong to the symmetry point group C2h and are located about special positions with site symmetry 2/m. In (II), both molecules show crystallographic inversion symmetry. In both structures, there are C,H..., contacts between aromatic H atoms and the ,-electrons of the triple bond. In addition to these, in (II) there are C,H..., contacts between aromatic H atoms and the ,-electron cloud of the benzene molecules. [source] Mono- and bis-tolylterpyridine iridium(III) complexesACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010Lindsay 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] Two pentadehydropeptides with different configurations of the ,Phe residuesACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010Maciej Makowski Comparison of the crystal structures of two pentadehydropeptides containing ,Phe residues, namely (Z,Z)- N -(tert -butoxycarbonyl)glycyl-,,,-phenylalanylglycyl-,,,-phenylalanylglycine (or Boc0,Gly1,,ZPhe2,Gly3,,ZPhe4,Gly5,OH) methanol solvate, C29H33N5O8·CH4O, (I), and (E,E)- N -(tert -butoxycarbonyl)glycyl-,,,-phenylalanylglycyl-,,,-phenylalanylglycine (or Boc0,Gly1,,EPhe2,Gly3,,EPhe4,Gly5,OH), C29H33N5O8, (II), indicates that the ,ZPhe residue is a more effective inducer of folded structures than the ,EPhe residue. The values of the torsion angles , and , show the presence of two type-III,,-turns at the ,ZPhe residues and one type-II ,-turn at the ,EPhe residue. All amino acids are linked trans to each other in both peptides. ,-Turns present in the peptides are stabilized by intramolecular 4,1 hydrogen bonds. Molecules in both structures form two-dimensional hydrogen-bond networks parallel to the (100) plane. [source] Clindamycin hydrochloride monohydrate and its ethanol solvateACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2010Krishnan Ravikumar Clindamycin hydrochloride, an antibiotic of the lincomycin family, was crystallized as the monohydrate, namely (2S,4R)-2-(N -{(1S,2S)-2-chloro-1-[(3R,4S,5R,6R)-3,4,5-trihydroxy-6-(methylsulfanyl)perhydropyran-2-yl]propyl}aminocarbonyl)-4-propylpyrrolidinium chloride monohydrate, C18H34ClN2O5S+·Cl,·H2O, (I), and as the monohydrate ethanol solvate, C18H34ClN2O5S+·Cl,·H2O·C2H6O, (II). The conformation of the clindamycin molecule in both crystal structures is the same and is found to be similar to that in enzyme-bound clindamycin. The simultaneous presence of free chloride ions and water molecules in (I) and of additional ethanol molecules in (II) provides an interesting network of hydrogen bonds. The significance of this study lies in the interactions in these structures and the aggregations occurring via hydrogen bonds in the hydrated and solvated crystalline forms of the title compound. [source] (,5 -Cyclopentadienyl)[(1,2,3,4,4a,10a-,)-1-methylthianthrene]iron(II) hexafluoridophosphate acetone 0.33-solvateACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2009Arthur D. Hendsbee The title complex salt, [Fe(C5H5)(C13H10S2)]PF6·0.33C3H6O, obtained from an acetone,diethyl ether,dichloromethane mixture at 280,(2),K, has three cationic molecules (A,C), three hexafluoridophosphate counter-anions and one acetone solvent molecule in the asymmetric unit. Two of the three cations contain FeCp (Cp is cyclopentadienyl) inside the fold of the heterocycle. The dihedral angles between the planes of the external (complexed and uncomplexed) benzene rings in the thianthrene molecule are 146.5,(2)° for FeCp-out-of-fold molecule A, and 139.0,(3) and 142.5,(2)° for the two FeCp-in-fold molecules B and C, respectively. The complexed Cp and benzene rings in each molecule are almost parallel, with a dihedral angle between the planes of 0.2,(5)° for molecule A, 2.8,(5)° for B, and 2.19,(4) and 6.86,(6)° for the disordered Cp ring in C. [source] New pseudopolymorphs of 5-fluorocytosineACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009Maya Tutughamiarso In order to better understand the interaction between the pharmaceutically active compound 5-fluorocytosine [4-amino-5-fluoropyrimidin-2(1H)-one] and its receptor, hydrogen-bonded complexes with structurally similar bonding patterns have been investigated. During the cocrystallization screening, three new pseudopolymorphs of 5-fluorocytosine were obtained, namely 5-fluorocytosine dimethyl sulfoxide solvate, C4H4FN3O·C2H6OS, (I), 5-fluorocytosine dimethylacetamide hemisolvate, C4H4FN3O·0.5C4H9NO, (II), and 5-fluorocytosine hemihydrate, C4H4FN3O·0.5H2O, (III). Similar hydrogen-bond patterns are observed in all three crystal structures. The 5-fluorocytosine molecules form ribbons with repeated R22(8) dimer interactions. These dimers are stabilized by N,H...N and N,H...O hydrogen bonds. The solvent molecules adopt similar positions with respect to 5-fluorocytosine. Depending on the hydrogen bonds formed by the solvent, the 5-fluorocytosine ribbons form layers or tubes. A database study was carried out to compare the hydrogen-bond pattern of compounds (I),(III) with those of other (pseudo)polymorphs of 5-fluorocytosine. [source] Channel-forming solvates of 6-chloro-2,5-dihydroxypyridine and its solvent-free tautomer 6-chloro-5-hydroxy-2-pyridoneACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Sean R. Parkin On crystallization from CHCl3, CCl4, CH2ClCH2Cl and CHCl2CHCl2, 6-chloro-5-hydroxy-2-pyridone, C5H4ClNO2, (I), undergoes a tautomeric rearrangement to 6-chloro-2,5-dihydroxypyridine, (II). The resulting crystals, viz. 6-chloro-2,5-dihydroxypyridine chloroform 0.125-solvate, C5H4ClNO2·0.125CHCl3, (IIa), 6-chloro-2,5-dihydroxypyridine carbon tetrachloride 0.125-solvate, C5H4ClNO2.·0.125CCl4, (IIb), 6-chloro-2,5-dihydroxypyridine 1,2-dichloroethane solvate, C5H4ClNO2·C2H4Cl2, (IIc), and 6-chloro-2,5-dihydroxypyridine 1,1,2,2-tetrachloroethane solvate, C5H4ClNO2·C2H2Cl4, (IId), have I41/a symmetry, and incorporate extensively disordered solvent in channels that run the length of the c axis. Upon gentle heating to 378,K in vacuo, these crystals sublime to form solvent-free crystals with P21/n symmetry that are exclusively the pyridone tautomer, (I). In these sublimed pyridone crystals, inversion-related molecules form R22(8) dimers via pairs of N,H...O hydrogen bonds. The dimers are linked by O,H...O hydrogen bonds into R46(28) motifs, which join to form pleated sheets that stack along the a axis. In the channel-containing pyridine solvate crystals, viz. (IIa),(IId), two independent host molecules form an R22(8) dimer via a pair of O,H...N hydrogen bonds. One molecule is further linked by O,H...O hydrogen bonds to two 41 screw-related equivalents to form a helical motif parallel to the c axis. The other independent molecule is O,H...O hydrogen bonded to two related equivalents to form tetrameric R44(28) rings. The dimers are ,,, stacked with inversion-related dimers, which in turn stack the R44(28) rings along c to form continuous solvent-accessible channels. CHCl3, CCl4, CH2ClCH2Cl and CHCl2CHCl2 solvent molecules are able to occupy these channels but are disordered by virtue of the site symmetry within the channels. [source] Proton transfer versus nontransfer in compounds of the diazo-dye precursor 4-(phenyldiazenyl)aniline (aniline yellow) with strong organic acids: the 5-sulfosalicylate and the dichroic benzenesulfonate salts, and the 1:2 adduct with 3,5-dinitrobenzoic acidACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Graham Smith The structures of two 1:1 proton-transfer red,black dye compounds formed by reaction of aniline yellow [4-(phenyldiazenyl)aniline] with 5-sulfosalicylic acid and benzenesulfonic acid, and a 1:2 nontransfer adduct compound with 3,5-dinitrobenzoic acid have been determined at either 130 or 200,K. The compounds are 2-(4-aminophenyl)-1-phenylhydrazin-1-ium 3-carboxy-4-hydroxybenzenesulfonate methanol solvate, C12H12N3+·C7H5O6S,·CH3OH, (I), 2-(4-aminophenyl)-1-phenylhydrazin-1-ium 4-(phenyldiazenyl)anilinium bis(benzenesulfonate), 2C12H12N3+·2C6H5O3S,, (II), and 4-(phenyldiazenyl)aniline,3,5-dinitrobenzoic acid (1/2), C12H11N3·2C7H4N2O6, (III). In compound (I), the diazenyl rather than the aniline group of aniline yellow is protonated, and this group subsequently takes part in a primary hydrogen-bonding interaction with a sulfonate O-atom acceptor, producing overall a three-dimensional framework structure. A feature of the hydrogen bonding in (I) is a peripheral edge-on cation,anion association also involving aromatic C,H...O hydrogen bonds, giving a conjoint R12(6)R12(7)R21(4) motif. In the dichroic crystals of (II), one of the two aniline yellow species in the asymmetric unit is diazenyl-group protonated, while in the other the aniline group is protonated. Both of these groups form hydrogen bonds with sulfonate O-atom acceptors and these, together with other associations, give a one-dimensional chain structure. In compound (III), rather than proton transfer, there is preferential formation of a classic R22(8) cyclic head-to-head hydrogen-bonded carboxylic acid homodimer between the two 3,5-dinitrobenzoic acid molecules, which, in association with the aniline yellow molecule that is disordered across a crystallographic inversion centre, results in an overall two-dimensional ribbon structure. This work has shown the correlation between structure and observed colour in crystalline aniline yellow compounds, illustrated graphically in the dichroic benzenesulfonate compound. [source] Bis(tetraphenylphosphonium) (hexasulfido-2,2S1,S6)di-,-sulfido-disulfido-1,2S -tungsten(VI)zinc(II) acetone solvateACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Azizolla Beheshti The title complex, (C24H20P)2[WZnS4(S6)]·C3H6O or (Ph4P)2[WS2(,-S)2{Zn(S6)}]·Me2CO, was unexpectedly obtained on attempted recrystallization of a mixed tungten,zinc complex of a tris(pyrazolato)borate ligand. The two metal centres of the anion have distorted tetrahedral coordination and the two tetrahedra share one S...S edge; tungsten is additionally coordinated by two terminal sulfide ligands and zinc by a chelating S62, ligand, which has one central S,S bond significantly longer than the other four, a pattern found to be consistent for this ligand. This is the first reported example of a tetrahedral zinc centre bridging an edge of a single tetrathiotungstate(VI) or tetrathiomolybdate(VI) anion, although there are many previous examples with other metals. [source] A bis(amine,carboxylate) copper(II) coordination compound forms a two-dimensional metal,organic framework when crystallized from water and methanolACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Orde Q. Munro When {2,2,-[(2-methyl-2-nitropropane-1,3-diyl)diimino]diacetato}copper(II), [Cu(C8H13N3O6)], (I), was crystallized from a binary mixture of methanol and water, a monoclinic two-dimensional water- and methanol-solvated metal,organic framework (MOF) structure, distinctly different from the known orthorhombic one-dimensional coordination polymer of (I), was isolated, namely catena -poly[[copper(II)-,3 -2,2,-[(2-methyl-2-nitropropane-1,3-diyl)diimino]diacetato] methanol 0.45-solvate 0.55-hydrate], {[Cu(C8H13N3O6)]·0.45CH3OH·0.55H2O}n, (II). The monoclinic structure of (II) comprises centrosymmetric dimers stabilized by a dative covalent Cu2O2 core and intramolecular N,H...O hydrogen bonds. Each dimer is linked to four neighbouring dimers via symmetry-related (opposing) pairs of bridging carboxylate O atoms to generate a `diamondoid' net or two-dimensional coordination network. Tight voids of 166,Å3 are located between these two-dimensional MOF sheets and contain a mixture of water and methanol with fractional occupancies of 0.55 and 0.45, respectively. The two-dimensional MOF sheets have nanometre-scale spacings (11.2,Å) in the crystal structure. Hydrogen-bonding between the methanol/water hydroxy groups and a Cu-bound bridging carboxylate O atom apparently negates thermal desolvation of the structure below 358,K in an uncrushed crystal of (II). [source] Structural comparisons between methylated and unmethylated nitrophenyl lophinesACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009Diana Yanover The lophine derivative 2-(2-nitrophenyl)-4,5-diphenyl-1H -imidazole, C21H15N3O2, (I), crystallized from ethanol as a solvent-free crystal and from acetonitrile as the monosolvate, C21H15N3O2·C2H3N, (II). Crystallization of 2-(4-nitrophenyl)-4,5-diphenyl-1H -imidazole from methanol yielded the methanol monosolvate, C21H15N3O2·CH4O, (III). Three lophine derivatives of methylated imidazole, namely, 1-methyl-2-(2-nitrophenyl)-4,5-diphenyl-1H -imidazole methanol solvate, C22H17N3O2·CH4O, (IV), 1-methyl-2-(3-nitrophenyl)-4,5-diphenyl-1H -imidazole, C22H17N3O2, (V), and 1-methyl-2-(4-nitrophenyl)-4,5-diphenyl-1H -imidazole, C22H17N3O2, (VI), were recrystallized from methanol, acetonitrile and ethanol, respectively, but only (IV) produced a solvate. Compounds (III) and (IV) each crystallize with two independent molecules in the asymmetric unit. Five imidazole molecules in the six crystals differ in their molecular conformations by rotation of the aromatic rings with respect to the central imidazole ring. In the absence of a methyl group on the imidazole [compounds (I),(III)], the rotation angles are not strongly affected by the position of the nitro group [44.8,(2) and 45.5,(1)° in (I) and (II), respectively, and 15.7,(2) and 31.5,(1)° in the two molecules of (III)]. However, the rotation angle is strongly affected by the presence of a methyl group on the imidazole [compounds (IV),(VI)], and the position of the nitro group (ortho, meta or para) on a neighbouring benzene ring; values of the rotation angle range from 26.0,(1) [in (VI)] to 85.2,(1)° [in (IV)]. This group repulsion also affects the outer N,C,N bond angle. The packing of the molecules in (I), (II) and (III) is determined by hydrogen bonding. In (I) and (II), molecules form extended chains through N,H...N hydrogen bonds [with an N...N distance of 2.944,(5),Å in (I) and 2.920,(3),Å in (II)], while in (III) the chain is formed with a methanol solvent molecule as the mediator between two imidazole rings, with O...N distances of 2.788,(4),2.819,(4),Å. In the absence of the imidazole N,H H-atom donor, the packing of molecules (IV),(VI) is determined by weaker intermolecular interactions. The methanol solvent molecule in (IV) is hydrogen bonded to imidazole [O...N = 2.823,(4),Å] but has no effect on the packing of molecules in the unit cell. [source] Three solvates of a bis-mesoionic fluorescent yellow pigmentACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2009Jürgen Brüning p -Phenylenebis(2-oxo-3-phenyl-1,2-dihydropyrido[1,2- a]pyrimidin-5-ium-4-olate), C34H22N4O4, is a bis-mesoionic yellow pigment that shows fluorescence in the solid state. During a polymorph screening, single crystals of three solvates were grown and their crystal structures determined. Solvent-free crystals were not obtained. A solvate with N -methylpyrrolidone (NMP) and propan-2-ol, C34H22N4O4·2C5H9NO·C3H8O, (Ia), and an NMP trisolvate, C34H22N4O4·3C5H9NO, (Ib), crystallize with pigment molecules on inversion centres. The NMP/propan-2-ol mixed solvate (Ia) forms O,H...O hydrogen bonds between the different solvent molecules. In both structures, at least one of the solvent molecules is disordered. A third solvate structure, C34H22N4O4·0.5C5H9NO·C4H10O, (Ic), was obtained by crystallization from NMP and butan-1-ol. In this case, there are two symmetry-independent pigment molecules, both situated on inversion centres. The solvent molecules are heavily disordered and their contribution to the scattering was suppressed. This solvate displays a channel structure, whereas the other two solvates form layer structures. [source] Mn3(OAc)6·CH3CN: a porous dehydrated manganese(II) acetateACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2009John Fielden The crystal structure of a new form of dehydrated manganese(II) acetate, poly[[hexa-,3 -acetato-trimanganese(II)] acetonitrile solvate], {[Mn3(CH3COO)6]·CH3CN}n, (I), reveals a three-dimensional polymeric structure based on an {Mn3} trimer. The {Mn3} asymmetric unit contains three crystallographically independent Mn positions, comprising a seven-coordinate center sharing a mirror plane with a six-coordinate center, and another six-coordinate atom located on an inversion center. Two of the four crystallographically independent acetate (OAc) ligands, as well as the acetonitrile solvent molecule, are also located on the mirror plane. The Mn atoms are connected by a mixture of Mn,O,Mn and Mn,OCO,Mn bridging modes, giving rise to face- and corner-sharing interactions between manganese polyhedra within the trimers, and edge- and corner-sharing connections between the trimers. The network contains substantial pores which are tightly filled by crystallographically located acetonitrile molecules. This structure represents the first porous structurally characterized phase of anhydrous manganese(II) acetate and as such it is compared with the closely related densely packed anhydrous manganese(II) acetate phase, solvent-free ,-Mn(OAc)2. [source] | ||||||||||