Crystal and molecular structure of 6-chloro-3-cyclopentylmethyl-3,4-dihydro-7-sulfamyl-2H-1,2,4-benzothiadiazine-1,1-dioxide

The crystal structure of the title compound, C₁₃H₁₈N₃O₄S₂C1, a sulfa drug, has been determined by X-ray diffraction data using MoK radiation. The crystals are orthorhombic,Pbca, witha=9.441(4),b=29.633(11),c=12.167(8) Å andZ=8. The structure was solved by the heavy-atom method, and refined by full matrix least-squares to a finalR value of 0.054 with 2062 observed reflections. In the crystal, the molecules are linked by N-HO hydrogen bonds.     

Molecular structure of 4-p-hydroxyphenyl-3,5-dimethylpyrazole monohydrate

The crystal and molecular structure of the monohydrate of 4-p-hydroxyphenyl-3,5-dimethylpyrazole have been determined by X-ray analysis. The compound crystallizes in the orthorhombicFddd space group witha=31.6886(19),b=22.6453(12),c=12.0800(4) Å,V=8668.6(8) ų,Dc=1.264 g/cm³ andZ=32. The crystal packing is mainly due to strong O–H...O/N and N–H...O hydrogen bond interactions.     

Crystal and molecular structure of 1,1′,3,3′-tetraphenyloxaldiamidrazone

1,1,3,3-Tetraphenyloxaldiamidrazone, C₂₆H₂₄N₆, crystallizes in the monoclinic system: space groupP2₁/c,a= 13.946(1) Å,b= 5.706(1) Å,c= 17.109(1) Å, = 125.31(1) °,D _m = 1.254,D _c = 1.259 gcm^–3 andZ= 2. Intensities were obtained from –2 scans with a Syntex automated diffractometer using graphite-monochromated MoK radiation. The structure was solved by direct methods. Full-matrix least-squares refinement of all positional and thermal (anisotropic for the nonhydrogen atoms and isotropic for the hydrogen atoms) parameters using 2022 reflections [I>2(itI)] converged at a conventionalR of 0.041. The molecule is characterized by a conjugated pi system which includes the central N=C–C=N moiety and two of the four aniline groups. No intermolecular and only weak intramolecular hydrogen bonds are present.     

Crystal and molecular structure of 4-aminoacetyl-N-p-nitrophenylsulfanilamide

The crystal and molecular structure of 4-aminoacetyl-N-p-nitrophenylsulfanilamide (C₁₄H₁₃N₃O₅S), a derivative of sulfonamide, has been determined from X-ray diffraction data using Cu-K radiation. The compound crystallised in the monoclinic space groupP2₁/c, witha=12.258(9),b=7.339(5),c=16.359(9) Å,=98.84(4)°. The structure was solved by direct methods and refined by full-matrix least-squares to a finalR value of 0.047 with 2487 unique reflections. In packing, the molecules are found to be stabilised by N-H O hydrogen bonds.     

Crystal and molecular structure of 4-cyanopyridine-N-oxide

Crystals of 4-cyanopyridine-N-oxide crystallize in space groupP2₁/c (No. 14). There are four molecules per unit cell, witha = 7.88(2),b = 6.10(2),c =11.61(3) Å and =101.4(4) °. Data for 838 unique reflections were recorded using the multiple-film technique and visually estimated intensities. A three-dimensional least-squares refinement of the structure was carried out to a final conventionalR of 0.098. It was found that the molecule was planar, as expected, and that the centrosymmetric pairs were stacked parallel to each other, as viewed down thea-axis. Bond distances and angles are in agreement with those from comparable molecules.     

Crystal and molecular structure of 4-amino-4-carboxyl thiapyran

4-Amino-4-carboxylthiapyran crystallizes in space groupP2₁/c witha = 10.61,b = 6.55,c= 10.97 Å, =96.3 °, andZ = 4. The structure was solved by the heavy-atom method, with 897 observed reflections, and refined to anR of 0.093. The packing of the structure is found to be very similar to that in the structure of 1-aminocyclohexane carboxylic acid. The conformation of the thiapyran ring exists in the puckered chair form.Contribution No. 410 from the Dept. of Crystallography and Biophysics, Univeristy of Madras, Guindy Campus, Madras-600025, India.     

Crystal and molecular structure of trans-4-t-butylcyclohexanol parabromobenzoate

The crystal and molecular structure oftrans-4-t-butylcyclohexanol parabromobenzoate has been studied by X-ray crystallographic methods. Crystals of this compound are triclinic, space groupP¯1, with unit cell constantsa = 9·813(2),b = 13·451(3),c = 6·564(3) Å, α = 102·99(3), β = 98·88(3), γ = 89·99(3) ° andZ = 2. Using a GE XRD-6 diffractometer equipped with a scintillation detector, 3165 reflexions were measured to the limit 2θ = 140 ° for the Cu sphere. The structure was refined by least-squares methods toR (conventional) = 0·058. The main results of this study are:

1. no flattening is induced into the cyclohexane ring and there is no elongation of the C(t-bu)-C(cyclohexane) bond;
2. the steric strain introduced by thet-butyl group is minimized by a flattening of the C(4), C(3), C(7), C(5) pyramid;
3. the axial hydrogen atom on C(1) nearly eclipses the carbonyl oxygen, as found in the earlier studies of the acetates and esters of cyclohexanols.

     

Crystal and molecular structure of 4-amino-4-carboxyl thiapyran hydrobromide

Journal of Chemical Crystallography - 4-Amino-4-carboxylthiapyran hydrobromide crystallizes in the monoclinic space groupP21/m, witha= 9.72 Å,b= 6.60 Å andc=7.10 Å,β = 94.8...     

Crystal and molecular structure of three 4-methyl morpholinium chlorides

The crystal and molecular structures of three 4-methylmorpholimum chlorides have been determined. The corresponding bond lengths and angles are the same in all three molecules and the methyl and phenyl groups are equatorially linked to the morpholine ring. The chlorine atoms are strongly hydrogen bonded to the protonated nitrogen atoms. The distances of the N-atom from the centers of the equatorial phenyl groups have an average value of 4.727 Å, while in one compound, BENZYL, this distance from the axial phenyl group is 6.08 Å.     

Crystal and molecular structure of 1,3-diphenyl-4-p-chlorobenzal-5-pyrazolone

Crystals of 1,3-diphenyl-4-p-chlorobenzal-5-pyrazolone, C₂₂H₁₅ClNN₂O, are triclinic:a = 13.96,b = 12.94,c = 7.29 Å, = 93.0 ° = 100.1 °, = 135.6 °,Z = 2, space groupP¯1. The structure has been determined from Weissenberg X-ray data by direct methods, and refined by full-matrix least squares toR = 0.098 for 1949 observed reflexions. The molecular conformation of the double bond at chlorobenzal is of type Z. The phenyl rings make angles of 9.2 ° and 47.7 ° and thep-chlorophenyl group an angle of 4.2 ° all with the plane of the pyrazolone moiety, thus allowing extended conjugation. Comparisons of bond distances and angles with those of similar molecules are made. Close molecular packing is afforded by layers of molecules approximately parallel to (¯110).     

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 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 °.