Crystal and molecular structure of sarcosine hydrochloride

Sarcosine hydrochloride (C₃H₈NO₂ ⁺·C1^–) crystallizes in the monoclinic space groupP2₁ with two molecules per unit cell of dimensionsa = 9.00,b = 5.93,c = 5.41 Å, and = 96.0 °. The structure has been solved by the heavy-atom method, using intensities estimated visually from X-ray photographs. The structure has been refined by full-matrix least squares, the finalR value being 0.10. The sarcosine molecule does not occur in zwitterion form. The molecules are planar and maximally extended, and are held together by a network of hydrogen bonds of the types N-HCl^– and O-HCl^–, and by van der Waals' forces. The amino nitrogen forms two hydrogen bonds with two chloride ions and assumes a tetrahedral configuration.     

Crystal and molecular structure of morpholine biguanide hydrochloride

Crystals of morpholine biguanide hydrochloride, C₆H₁₃N₅O. HC1, belong to the orthorhombic space groupPbca;a = 19·02 Å,b = 9·92 Å,c = 10·34 Å andZ = 8. The structure has been solved by three-dimensional Patterson and heavy-atom Fourier syntheses. The hydrogen positions have been located from a three-dimensional difference Fourier synthesis. The positional coordinates of all the atoms and their temperature factors (anisotropic for non-hydrogen atoms and isotropic for hydrogen atoms) have been refined by three-dimensional least-squares methods. The finalR value is 0·087.The morpholine ring has been found to assume a chair configuration. The contribution of various valence bond structures to the normal state of the morpholine biguanide hydrochloride molecule has been studied with reference to the characters of the C-N bonds in the biguanide part of the molecule. Both the guanidine groups are planar. Of six available hydrogen atoms, only four take part in forming hydrogen bonds of the type N-H···Cl^–. The molecules in the crystal are linked by a three-dimensional network of hydrogen bonds.Our thanks are due to the staff of the Computing Centres at IIT, Kharagpur and TIFR, Bombay.     

Crystal and molecular structure of the alkaloid papaverine hydrochloride

The crystal and molecular structure of the benzylisoquinoline alkaloid papaverine hydrochloride, C₂₀H₂₁NO₄. HCl, has been determined with CuKα diffractometer data by direct methods. The compound crystallizes in the monoclinic space groupP2₁/c (No. 14) witha= 13.059(3),b = 15.620(3),c = 9.130(2) Å and β = 92.14(1) °. The structure was refined by full-matrix least-squares methods toR = 0.052 using all 2652 reflections. The nitrogen atoms is protonated and forms a strong hydrogen bond with the chloride ion, the N ... Cl distance being 3.01 Å. The isoquinoline ring is slightly non-planar but the benzene ring is planar within experimental error. The dihedral angle between the benzene ring and the best plane through the isoquinoline group is 109 °. The molecular structure of papaverine is of interest in gaining a better understanding of its pharmacological action on smooth muscle.     

Crystal and molecular structure of hexahydropyridine (piperidine) hydrochloride

The structure of hexahydro pyridine (piperidine), a compound of psychobiological importance, has been determined in the form of its hydrochloride by the heavy-atom technique, using three-dimensional X-ray data. Hexahydro pyridine hydrochloride, (C₅H₅N)H₆.HC1, crystallizes in the orthorhombic space groupPbcm with four molecules per unit cell of dimensionsa = 9.68(2),b = 7.30(3),c = 9.67(2) Å. The positions of the hydrogen atoms were located from a difference-Fourier synthesis. The structure was refined by the full-matrix least-squares method, using anisotropic temperature factors, leading to the finalR-value of 0.094. The hexahydro pyridine ring has a chair conformation. The crystallographic mirror plane atz = 1/4 coincides with the molecular mirror plane passing through the C1, N and C(3) atoms of the molecule in such a way that C(1)′ and C(2)′ are the mirror images of C(1) and C(2). The dihedral angles which plane I, containing C(1), C(2), C(2)′ and C(1)′, makes with plane II, containing C(2), C(3) and C(2)′, and planeIII, containing C(1), N and C(1)′, are 120.47 and 116∶42 °, respectively. The molecules are held together by a network of hydrogen bonds of type N⁺ —H ... C1^? in thexy-plane, and by van der Waals forces in thez-direction. Both the hydrogen atoms in the NH ₂ ⁺ group of the molecule take part in the formation of hydrogen bonds.     

Crystal and molecular structure of 1,N6-ethenoadenosine hydrochloride

The X-ray structure of 1,N ⁶-ethenoadenosine hydrochloride, C₁₂H₁₄N₅O₄Cl, has been determined from three-dimensional diffractometer data and refined by full-matrix least-squares techniques. The crystals are monoclinic:P2₁ No. 14,a=6.1540(5),b=18.511(1),c=6.7412(4) Å,=112.602(5)°,andZ=2; finalR=0.045 for 2662 observed reflections. The crystal and molecular structure of Ado·HC1 is very similar to that of Ado·HC1. On the other hand, the dimensions and conformation of the Ado·H⁺ cation are drastically different from those of Et Ado·H⁺. The adenosine·H⁺ moiety is not planar but has an S shape. The ribose is 2-endo-3-exo puckered, with ag ⁺ side chain; the glycosidic torsion angle is in theanti region. The structure contains a three-dimensional network of H bonds in which also C-HA interactions seem to play an important role. There is no base stacking in the structure.     

Crystal structure of tolazoline hydrochloride

The title compound (C₁₀H₁₂N₂ HC1,M _r =196.7) crystallizes in the monoclinic space groupP2₁/c witha=8.997(1),b=9.665(1) andc=12.290(1) Å,=104.41(1)°,V=1035·1 ų,D _x =1.262 g·cm^–3 forZ=4,=29.4 cm^–1, (CuK)=1.54178 Å,F(000)=416. FinalR=0.051 (R _w =0.063) for 1937 reflections collected on a diffractometer. The structure was solved by direct methods. The two N atoms of the imidazoline ring are equivalent due to protonation and they participate in N-HCl hydrogen bonds which join the molecules into infinite chains. The imidazoline ring is approximately planar and is oriented perpendicular to the plane of the benzene ring. The separations of the two N atoms from the center of the aromatic ring are 4.691(3) and 4.598(3) Å, close to the values found in the crystal structures of clonidinelike agents.     

Crystal and molecular structure ofo-chlorobenzylidenemalononitrile

The crystal structure ofo-chlorobenzylidenemalononitrile, C₁₀H₅ClN₂, has been determined by X-ray crystallographic analysis. The compound crystallizes in the monoclinic space groupP2₁/c, with unit cell dimensionsa = 3·971,b = 21·140,c = 10·747 Å, = 95·29 °;Z = 4. The structure was solved by matching an assumed molecular shape to the near-origin peaks of a sharpened vector map, the detail being established by Fourier syntheses. Refinement by full-matrix least squares converged to an indexR of 0·097 for 1729 reflections from CuK Weissenberg photographs.The molecular components, the phenyl and malononitrile groups, are individually planar but mutually tilted with a dihedral angle of 12·7 °. The deviation from planarity is related to steric hindrance between the malononitrile group and theortho-hydrogen of the phenyl ring.     

Crystal and molecular structure of reductiomycin

Conflicting results concerning the structure of the antitumor agent reductiomycin have been resolved. When the imino group and the heterocyclic oxygen atom of a previous x-ray study are interchanged, and this structure refined, it is found that: (i) a structure with satisfactory hydrogen bonding results, (ii) there are no unacceptably small nonbonded intermolecular distances, and (iii) agreement with two recent structure formulations based on various kinds of chemical and spectral evidence is achieved.Camille and Henry Dreyfus Teacher Scholar, 1978–1983; National Institutes of Health (National Cancer Institute) Career Development Awardee, 1980–1985.     

Crystal and molecular structure of dichlorofluoroacetamide

The crystal structure of dichlorofluoroacetamide has been determined from three-dimensional counter data, and refined by full-matrix least-squares techniques. The crystals belong to the monoclinic space groupP2₁ /c and have the unit-cell parametersa = 10.207(4),b = 5.729(2),c = 9.971(4) Å, = 105.21(8) °, andD _x = 1.72 g cm^-3. The structural refinement gave a finalR factor of 0.067 from 440 observed reflections. The compound has nearly equal disorder of the -Cl₂F moiety about the C-C bond axis with occupancy factors of the two fragments being 0.48 and 0.52.     

Crystal and molecular structure of dithiobiuret

The crystal and molecular structure of dithiobiuret (S₂C₂N₃H₅) has been determined and refined from 1020 intensities measured by counter techniques at room temperature. The full-matrix refinement, including anisotropic temperature factors for the non-hydrogen atoms and isotropic temperature factors for the hydrogen atoms, converged to a finalR of 0·033. The structure consists of almost planar molecules in thetrans configuration with essentially only van der Waals interactions between molecules. The two independent C-S distances are 1·702(3) and 1·673(3) Å. The internal C-N distances are 1·386(4) and 1·367(4) Å, whereas the external C-N distances are 1·331(4) and 1·309(4) Å. The unit cell parameters area = 4·081(1),b = 17·684(5),c = 8·222(3) Å and = 100·56(2) °;Z = 4,D _m =D _c = 1·54 gcm^–3; the space group isP2₁/c.     

Crystal and molecular structure of L-N-acetylhistidinamide

The title compound crystallizes in the monoclinic space group P 2₁ with 2 formula units C₈H₁₂N₄O₂ in the unit cell. The lattice parameters are a = 8.529, b = 11.735, c = 4.925 Å, and β = 94.61°. The crystal structure has been determined by direct methods and refined by full-matrix least squares calculations to the discrepancy factor R = 0.033.     

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 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 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 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 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 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 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 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 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.