Crystal and molecular structure of chlorotris(triphenylarsine)Cu(1),C54H45As3CuCl

The title compound crystallizes in the monoclinic space groupP2₁/n, witha=28.494(2),b=10.148(5),c=32.172(2) Å,=94.57(1)°, andZ=8 (with two independent molecules in the asymmetric unit). The structure was solved by direct methods and refined by block-diagonal least-squares methods toR=0.057 for 12286 observed reflections. The dimensions and conformations of the two independent molecules are closely similar. The coordination around the copper and arsenic atoms is approximately tetrahedral, although distortion is considerable. Some important mean bond distances and angles with their rms standard deviations are: Cu-Cl=2.270(4), Cu-As=2.419(4), As-C=1.953(2) Å, Cl-Cu-As=105.4(1.2), and As-Cu-As=113.3(8)°.     

Crystal and molecular structure of cyclotriveratrylene

Slow evaporation of a solution made from rigorously dried toluene and cyclotriveratrylene (CTV) has led to crystals of the guest-free CTV. These belong to the monoclinic space groupP2₁/n witha=12.582(3),b=9.575(5),c=19.738(5) Å,=95.15(2)°;D _c =1.26 g cm^–3 forZ=4. Refinement based on 1708 observed reflections led toR=0.045. The nine-membered ring of the CTV has the expected crown conformation.     

Crystal and molecular structure of geiparvarin

The structure of the antitumor agent geiparvarin was determined by direct methods from CuK diffractometer data. The crystals of synthetic geiparvarin have the space groupP2₁/c witha = 8.305(1),b = 11.077(1),c = 18.287(1) Å, = 98.79(1) °, andZ = 4. The structure was refined toR = 0.047. The chemically determined structure was confirmed. Bond distances and angles are normal and there are no unusual C-H O intermolecular contacts.IUPAC name: 7-[3-(4,5-dihydro-5,5-dimethy1-4-oxo-2-furanyl)-2-butenyi]-oxy-(2H-1-benzopyran-2-one).Camille and Henry Dreyfus Teacher-Scholar, 1978–1983; National Institutes of Health Career Development Award, 1980–1985.     

Crystal and molecular structure of augustamine

The crystal and molecular structure of augustamine (1), C₁₇H₁₉NO₄ an amaryllidaceae alkaloid of the tazettine group has been determined by direct methods from single crystal x-ray diffractometer data and refined by full-matrix least squares. The alkaloid (1) crystallizes in the space group P2₁2₁2₁, with cell parameters: a = 7.833(8) b = 11.08(2) å, c = 16.69(6) Å, Z = 4, D_c = 1.381 g/cm^–3, R = 7.6% for 1115 observed reflections. The molecule, having a hexacyclic ring system, is very rigid with the ring B in a chair conformation. Molecular mechanics calculations have been made using MM3(2000) force field.     

Crystal and molecular structure of pisatin

(+)-Pisatin, C₁₇H₁₄O₆, a lipophilic substance with antifungal activity, has been isolated fromPisum sativum L. following fungal inoculation. Orthorhombic crystals of the monohydrate belong to the space groupP2₁2₁2₁ witha = 6.910(3),b = 9.006(2),c = 24.253(4) Å, andZ = 4. The structure was solved by direct methods from diffractometer data measured with CuK radiation. Refinement with anisotropic temperature factors given to the non-hydrogen atoms converged atR = 0.058 for the 1255 observed terms. The molecular conformation is similar to the conformation recently reported for phaseollin, a related phytoalexin. Hydrogen bonds involving the water and pisatin molecules link the latter into infinite spirals extending alongb.     

Crystal and molecular structure of biruthenocene

Crystalline biruthenocene is disordered at room temperature. The apparent symmetry ofP2₁ c applies to an average structure only. Better resolution is achieved by refinement in the space groupP1. The room-temperature X-ray structure, as refined in both space groups, shows that the mutual orientation of cyclopentadienyl rings within a sandwich is not conformationally important and that it depends on intermolecular interactions.     

Crystal and molecular structure of diphenylthiosulphodiimide

The crystal and molecular structure of diphenylthiosulphodiimide, C₁₂H₁₀N₂S₃, has been solved by the symbolic addition procedure using three-dimensional CuK diffractometer data. The system is monoclinic,a = 30·41(3),b = 5·601(5),c = 7·792(8) Å, = 108·77(1) °, space groupC2/c andZ = 4. The structure was refined by full-matrix least-squares methods toR = 0·096 for 926 observed reflexions. All hydrogen positions have been determined. The molecule possesses a crystallographic diad axis through the central sulphur atom. The planes of the phenyl rings make an angle of 30·8 ° with the closely coplanar central five atoms.     

Crystal and molecular structure of bicuculline

The crystal and molecular structure of the phthalide isoquinoline alkaloid bicuculline, C₂₀H₁₇NO₆, has been determined by X-ray diffraction methods. The compound crystallizes in the orthorhombic space groupP2₁2₁2₁ (No. 19) witha = 14·49,b = 10·90 andc = 10·43 Å. The atomic parameters were refined by least squares to give a conventionalR-factor of 0·0437 for 1557 symmetry independent reflections.The bicuculline molecule consists of two approximate planes of atoms with a dihedral angle of 14·3 ° between them. The two planes are joined by the bond. The torsion angle is 164·1 ° in the crystal, but in the liquid state there would be partial free rotation about the bond.The structure of bicuculline is of current pharmacological interest as it is a relatively selective antagonist of -aminobutyric acid at various sites of the nervous system.     

Crystal and molecular structure of delsoline

The crystal and molecular structure of the diterpenoid alkaloid delsoline (1) C₂₅H₄₁NO₇, M_r 467.61, has been determined by an X-ray analysis. The X-ray crystal structure which could not be solved earlier withMultan, has now been solved using the SIR 88 analysis program. The compound crystallizes in the space groupP2₁2₁2₁ with cell parameters:a=12.529(2),b=13.118(1),c=14.231(6)Å,V=2339(1)ų,Z=4,D _calc=1.33 g/cm^–3, (CuK)=1.54184 Å,(CuK )=7.4 cm^–1,R/R _w =0.068/0.040 for 2539 reflections. The A ring of delsoline exists in the boat conformation stabilized by an intramolecular N---H-O hydrogen bond. Ring D also is in a boat form. Unambiguous proton and carbon-13 nmr assignments have been made by a detailed analysis of the DEPT, COSY, NOESY, and HETCOR nmr spectra.     

Crystal and molecular structure of chloramphenicol

Chloramphenicol, C₁₁H₁₂Cl₂N₂O₅, is orthorhombic, space groupC222₁,a = 17.495(3),b = 7.321(2),c = 22.130(4) Å, andZ = 8. The structure was solved by direct methods and refined to a finalR value of 0.068 for 1186 counter-reflections. Estimated standard deviations for bond lengths and bond angles involving nonhydrogen atoms average 0.009 Å and 0.6 °, respectively. All the hydrogen atoms that are bonded to O or N and are available for hydrogen-bond formation take part in the hydrogen-bonding network. The crystals become brown in color on prolonged exposure to X-rays and -rays. Our structural investigation with colored crystal does not indicate any structural change.     

Crystal and molecular structure of pentachloromonoisopropylaminocyclotriphosphazatriene

Crystals of N₃P₃C1₅ (NHC₃H₇) are monoclinic:a=15.059(7),b=14.815(5),c=6.501(6) Å, =95.03(6)°, space groupP2₁/n, and Z=4. The atomic positions were determined by direct methods and refined by least-squares refinement from diffractometer X-ray intensity data toR=0.063 for 1530 reflections. In the structure, pairs of molecules mutually related by a center of symmetry are linked by N-H N hydrogen bonds. The endocyclic P-N bonds range in length from 1.556 to 1.603 Å depending on the location of the bond relative to the isopropylamino group, and the exocyclic P-N bond is only a little longer (1.617 Å). The nongeminal P-Cl bond is significantly longer (2.036 Å) than the remaining P-Cl bonds (1.988–2.013 Å). The phosphazene ring shows only a very small departure from planarity. The isopropylamino group has a symmetrical conformation, with a Cl-P-N-C torsion angle of 90.5°.     

Crystal and molecular structure of benzylidenemalononitrile

Benzylidenemalononitrile, C₁₀H₆N₂ crystallizes in the monoclinic space group,P2₁/c;a = 9·385,b = 3·976,c = 22·152 Å, = 93·53 °,V _c = 825·03 ų,D _m = 1·231,D _c = 1·242 g cm^–3,Z= 4. The structure was solved by fitting cojointly an assumed molecular shape to both the near-origin peaks of the sharpened vector map and the distribution in the Harker (U,1/2,W) section, followed by trial-and-error establishment of the coordinates. The structure was then refined by full-matrix least squares, reducingR to 0·090 for data comprising 1412 reflexions (0·086, omitting 373 unobserved) from room temperature CuK Weissenberg photographs. Steric hindrance of the malononitrile group and a hydrogen atom in theortho position of the phenyl ring causes simultaneous expansion of the bond angles between the malononitrile group and the benzylidene group and rotations of these groups relative to each other. These constraints cause the two groups to be non-planar, the dihedral angle between their least-squares planes being 11·0 °.     

Crystal and molecular structure of piperidinium-acet-p-Cl-anilide-bromide

The crystal structure of piperidinium-acet-p-Cl-anilide-bromide is monoclinic, space group P 2₁/n with 8 formula units C₁₃H₁₈N₂OBrCl in the unit cell. The lattice constants are a = 7.337(2), b = 17.865(4), c = 22.822(5) Å, and β = 94.66(1)°. The title compound is not isomorphous to the corresponding chloride. Br ions are linked to the molecules by hydrogen bonds forming chains in the crystal structure.     

Crystal and molecular structure ofdl-lysine hydrochloride

The crystal structure ofdl-lysine hydrochloride has been determined by the heavy-atom technique, using three-dimensional X-ray photographic data. The crystals are monoclinic with space groupP2₁/c, a = 9.26(2),b = 11.36(2),c = 8.66(2) Å and = 105.4(4) °. The structure was refined by the full-matrix least-squares methods to a finalR value of 0.10. The torsion angles defining the side-chain conformation ofdl-lysine hydrochloride are significantly different from those ofl-lysine hydrochloride.     

Crystal and molecular structure of iso-grayanotoxin II

The crystal and molecular structure of a grayanotoxin derivative, iso-grayanotoxin II, is presented. The crystal is orthorhombic, space group . The molecule is based on a tetracyclic structure consisting of two five-membered, one six-membered, and one seven-membered rings with various conformations.     

Crystal and molecular structure of n-hexyloxyphenyl n-octyloxybenzoate

The X-ray crystal structure of n-hexyloxyphenyl n-octyloxybenzoate C₈H₁₇O-C₆H₄-COO-C₆H₄-OC₆H₁₃, which is a liquid-crystal compound, was determined. This compound forms smectic and nematic phases upon melting. A crystal-packing analysis revealed the following two types of structure-forming elements in the centrosymmetric pairs of molecules: a ??-stacking interaction and a C-H...??-system interaction. In the pairs of molecules linked by the latter type of interactions, there are two such interactions per pair, whereas one interaction occurs per pair of molecules linked by a ??-stacking interaction. Hence, the former pair of molecules is more stabilized through weak directional interactions than the latter pair.     

Crystal and molecular structure of tetramethylammonium picrate

The synthesis and crystal and molecular structure of the tetramethylammonium picrate [C₄H₁₂N⁺C₆H₂N₃O₇] is reported. It belongs to the triclinic space groupP¯1 witha=7.300(3),b=9.797(2),c=10.841(3)Å,=64.70(2),=88.60(3), =79.55(2)° andZ=2. The structure was refined to a finalR value equal to 0.046 (R _w =0.053) for 1817 unique reflections. The crystal packing consists of parallel layers of anions interacting through electrostatic and short van der Waals contacts with neighboring cations. Vibrational spectra have been recorded and discussed.This work is part of the systematic research activity of A.M. during the first year of his Dottorato di Ricerca in Scienze Chimiche at the Chemistry Department, University of Modena.     

Crystal and molecular structure of 13-oxolupanine

The title compound, C₁₅H₂₂N₂O₂, is monoclinic:P2₁,a=10.876(2),b=8.620(2),c=7.390(2) Å, β=99.2(2)°,Z=2. TheA/B ring junction configuration isquasi-trans, and theC/D junction istrans. RingA has a conformation intermediate between sofa and half-chair; ringsB,C, andD are in chair, boat, and distorted chair conformations, respectively.     

Crystal and molecular structure of crenatine carbonate

The crystal and molecular structure of 1-ethyl-4-methoxy-9H-pyrido[3,4b]indole (crenatine) carbonate C₁₄H₁₄N₂O·H₂CO₃, (MS, m/z 226)M _R 288.3, a-carboline alkaloid, has been determined from X-ray diffraction data. The compound crystallizes in the space group Pbca with cell parameters:a=11.616(4),b=18.450(8),c=12.992(5)Å,V=2784(2)ų,Z=8,D _calc=1.375 g cm^–3, (MoK)=0.71069Å,(Mo K)=0.94 cm^–1,F(000)=1216,R/R _w =8.2/10.3% for 1099 reflections. The ring system of the-carboline nucleus is planar. The title compound shows a two center hydrogen bond between the indole N-H group and the oxygen atom of a carbonate group. The structure does not display hydrogen bonding between-carboline groups but rather a bonding network involving the carbonate group.