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 grayanotoxin VII

The crystal and molecular structure of a grayanotoxin VII is presented. The crystal is monoclinic, space group P2₁, with a = 7.647(1) Å, b = 11.7591(7) Å, c = 10.0873(6) Å, = 91.143(8)°, V = 906.9(1) ų, Z = 2. The structure was solved by direct methods and refined by full-matrix least-squares methods to a final R = 0.057 for 1494 independent reflections. The molecule has a tetracyclic structure consisting of two five-membered, one six-membered, and one seven-membered rings.     

Crystal structure of the cytotoxic marine alkaloid 2-bromoleptoclinidinone

2-Bromoleptoclinidinone methanol solvate, C₁₈H₈BrN₃O·CH₄O, crystallizes in the orthorhombic space group Pbca with a = 15.7013(2), b = 7.3308(1), and c = 26.9326(1) Å. The molecule is essentially planar, with the largest deviations occurring at bromine (–0.21 Å), carbonyl oxygen O(l) (+0.19 Å) and in ring-A (C(9) –0.15 Å, C(10) –0.15 Å). Methanol occupies the 1,10-phenanthroline-like metal binding site of the title compound.     

Crystal and molecular structure of 10,20-epoxy-grayanotoxin-II

The photooxidation with HgO in benzene and the hydrolysis with 2%-KOH in methanol of the grayanotoxin (GTX) derivative (4) gave a 10,20-epoxy-grayanotoxin-II(5). The crystal structure of (5) has been determined by X-ray diffraction at room temperature. The crystal is monoclinic, space group P2₁, with a = 14.248(10) Å, b = 6.670(10) Å, c = 9.990(10) Å, = 105.507(8)°, V = 914.9(2) ų, Z = 2. The structure was solved by direct methods and refined by full-matrix least squares methods to a final R1 = 0.046 (wR2 = 0.0833) for 1161 independent reflections. The molecule has a pentacyclic structure consisting of two five-membered, one six-membered, one seven-membered, and one three-membered rings. The three-membered ring is connected with the seven-membered ring by spiro-type bond.     

Comparison of the crystal structure and molecular models of N,N-diisobutyl-2-(octylphenylphosphinyl)acetamide (CMPO)

The crystal structure of N,N-diisobutyl-2-(octylphenylphosphinyl)acetamide, or CMPO was recently determined. The compound crystallizes in the space group P2₁/c witha=13.446(6),b=22.280(7),c=17.217(7) Å, =92.07(4)°, andD _calc=1.05 g/cm³ forZ=8 @20°C). Molecular mechanics, molecular dynamics, and MNDO calculations were also performed on CMPO utilizing the SYBYL¹ suite of programs. The results from these calculations are compared to the crystal structure and to similar calculations performed on CMPO using ALCHEMY^2,3. In general, the results from the calculations agree fairly well with the parameters from the crystal structure.     

Crystal and molecular structure of 6-0-acetylgrayanotoxin III

The crystal and molecular structure of a grayanotoxin III derivative, 6-0-acetylgrayanotoxin III is presented. The crystal is orthorhombic, space group P2₁2₁2₁, witha=15.582(3),b=21.304(3),c=6.339(3)Å,V=2104(1) ų Z=4. The structure was solved by direct methods and refined by full matrix least-squares methods to a finalR=0.047 for 1763 independent reflections withF ₀>3 (F ₀) The molecule is based on a tetracyclic structure consisting of two five-membered, one six-membered, and one seven-membered ring with various conformations.     

Crystal structure of phenyl-substituted cyclopentenes

The crystal structures of two stereoisomers of tetraphenyl- and pentaphenyl-substituted cyclopentenes 1 and 2 have been determined by X-ray analysis. An envelope conformation ¹E has been ascertained for the cis isomer 1a, whereas the cis, cis isomer 2a, which crystallizes in two different space groups, P1¯ and P2₁/n, displays a twisted ²T₁ conformation. The phenyl substituents are all tilted with respect to the cyclopentene ring in both structures. Compound 1a crystallizes in the space group P2₁/a with a = 18.553(3), b = 6.006(2), c = 19.355(5), = 102.67(4)°, and V = 2104.2(g) ų for Z = 4; compound 2a ^I crystallizes in P2₁/n with a = 10.064(2), b = 20.756(5), c = 12.245(3) Å, = 95.21(2)°, and V = 2547(1) ų for Z = 4; compound 2aII crystallizes in P1¯ with a = 10.117(3), b = 11.750(2), c = 12.359(2) Å, = 111.25(2), = 94.84(2), = 108.78(2)°, and V = 1262.3(6) ų for Z = 2.     

Crystal and molecular structure of 6,7-benzo-3,4 (1,4-dimethoxy-2,3-naphtho)-1,5-dioxosuberane

The crystal and molecular structure of the title compound (2) C₂₁H₁₆O₄ has been determined by an X-ray analysis, by direct methods from diffractometer data and refined by full-matrix least squares. The compound (2) crystallizes in the space group P2₁/a, with cell parameters:a=36.432(5),b=5.512(3),c=8.269(5) Å, =108.0(3)°,z=4,D _c =1.397 g/cm^–3,R=7.8 for 1136 observed reflections. The conformation of the tetracyclic ring system shows a folding of two planar parts of the carbon skeleton about an axis passing thorough C8 and C16 of the seven membered ring C.     

Crystal structure and molecular dynamics simulation of tri-o-thymotide clathrates with thiophene as guest molecule

Tri-o-thymotide (TOT) forms a cage-type clathrate with the thiophene guest molecule in a host:guest ratio of 21. This clathrate crystallizes in the trigonal system (space groupP3₁21). The unit cell, of dimensionsa=b=13.585(4),c=29.914(12)Å, contains 6 TOT and one thiophene molecule. The crystal structure, established by direct methods (R=0.053), indicates that the host cavity has an oblate-ellipsoid shape with a crystallographic twofold axis parallel to the largest dimension of the cage. The guest molecule within the cavity is disordered. Molecular dynamics simulations have been performed and indicate that the guest molecules have hindered molecular freedom around the shortest ellipsoid axis of the cavity, and may produce a dynamic disorder in the cage of the TOT clathrate.     

Crystal and molecular structure studies of 2-(3-chlorophenyl),3,5-diphenylisoxazolidine

The structure of the title compound, 2-(3-chlorophenyl),3,5-diphenylisoxazolidine (C₂₁H₁₈ NOCl) (1) has been investigated by X-ray crystallography. Compound (1) crystallizes in orthorhombic space group P2₁2₁2₁ with cell parameters a=10.288(17) Å, b=37.98(3) Å, c=8.809(9) Å, Z=8. Compound (1) has both intra- and intermolecular hydrogen bonds.     

The crystal and molecular structure of N-(methylsulfonyl)-N-(2,6)-(dimethylphenyl)methanesulfonamide

The title compound, crystallizes in the triclinic space group witha=8.232(4),b=9.159(2),c=10.230(3)Å. =74.07(3)°, =72.50(4)°, =63.65(3)° andZ=2. The structure was solved by direct methods and refined by full matrix least squares methods toR=0.054 for 1817 observed reflections. The plane containing the nitrogen and sulfur atoms is perpendicular to the aromatic plane. One of the S–O bonds in each methanesulfonyl group is in nearly eclipsed conformation with the N–C bond.     

Crystal structure of trismorpholino phosphiniminocyclotrithiazene

The title compound (OC₄H₈N)₃P=N–S₃N₃ crystallizes in a monoclinic crystal system with unit cell parameters a = 8.9996(3), b = 17.2895(7), and c = 12.3648(9) Å, = 90.63(5)°, Z = 4, and space group P2₁/n. Strikingly the exocylic S1–N4 bond length is 1.545(3) ÅR and is accompanied by the largest angle at P–N4–S1 as 131.2(2)°. The tricoordinated sulfur atom of the cyclotrithiazene ring deviates from the mean plane of other five atoms by 0.654(1) Å.     

Crystal structure of nimbin

The crystal structure of nimbin has been determined. The crystals are orthorhombic, space groupP2₁2₁2₁ witha=6.790(2),b=14.875(4),c=27.160(8) Å andZ=4. The packing of the molecules in the lattice is due to C?H…O type of hydrogen bonds.     

Crystal and molecular structure of acetamidrazone derivatives

N ¹-acetylacetamidrazones and N ¹-benzoylacetamidrazones (1a–d) were characterized by ¹H and ¹³C NMR spectroscopy. The actual tautomeric form present has been shown to be the amide hydrazone. NMR spectra of N ¹-acetylacetamidrazones (1a,b) showed the existence of Z and E isomers in solution, while N ¹-benzoylacetamidrazones (1c,d) were present as Z isomers. The crystal structures of the amidrazones have been determined at 173 and 293 K, respectively. The amidrazones 1c and 1d crystallize in the monoclinic system: in particular for 1c space group P2₁/c, with a = 11.016(5), b = 20.594(14), c = 13.657(7) Å = 98.29(3)° V = 3066(3) ų and D _c = 1.243 g/cm³ for Z = 4; for 1d space group P2₁/a, with a = 9.410(5), b = 10.449(3), c = 14.295(11) Å = 101.04(5)° V = 1380(1) ų and D _c = 1.220 g/cm³ for Z = 4. The X-ray diffraction analysis carried out on 1c has shown the presence of three molecules in the asymmetric unit which differ for the orientation of the phenyl ring.     

Crystal and molecular structure of diphenylphosphinylacetic acid

Diphenylphosphinylacetic acid crystallizes in the monoclinic space groupP2_l/n with unit cell dimensionsa=5.6875(7),b=17.049(4),c=13.471(2) Å, =93.36(1)° and Z=4. The molecular packing consists of hydrogen bonded chains arising from intermolecular interactions between a carboxylic acid hydroxyl group and an oxygen of an adjacent phosphine oxide moiety.     

Crystal and molecular structure of o-methacryloylaminophenylarsonic acid

The title compound, o-methacryloylaminophenylarsonic acid (o-MAPHA), C₁₀H₁₂AsNO₄, is a monomer used to obtain water-soluble polyelectrolytes. It was obtained from the condensation reaction of o-arsanilic acid and methacryloyl chloride. Crystallization from aqueous ethanol solution yielded colorless prismatic crystals, and one was used for X-ray analysis. The crystal structure was solved using direct methods with a refined R ₁ = 0.0483. The crystal structure belongs to the triclinic system, space group , and the asymmetric unit comprises two molecules of the o-MAPHA acid and one water molecule. Both acid molecules are approximately planar and in both molecules the As atom presents common tetrahedral geometry with two long As–O bonds for hydroxyl groups and one short As–O bond for the oxo groups. The structure of o-arsanilic acid (o-ARSA), C₆H₈AsNO₃, was also determinated using the same methods and compared with the o-arsanilic acid structure previously reported. The crystal structure of the o-arsanilic acid belongs to the monoclinic crystal system and to the P2₁ noncentrosymmetric space group with Z equals two.     

Crystal structure of the molecular adduct of 5-mono[(4-nitrophenyl)azo]-25,26,27,28-tetrahydroxycalix[4]arene with chloroform (1:1)

The crystal structure of the molecular adduct of 5-mono[(4-nitrophenyl)azo]-25,26,27,28-tetrahydroxycalix[4]arene (2) with chloroform (C₃₄H₂₇N₃O₆ CHCl₃) was determined by X-ray crystallographic analysis. It was found to possess a monoclinic space group P2(1)/n, with a = 15.9306(13) Å, b = 10.6293(9) Å, c = 20.3194(17) Å, = 110.480(2)° and D_calc = 1.428 Mg/m³ for _Z = 4. Crystal data indicated that the calix[4]arene moiety of 2 exists in a distorted-cone conformation with intramolecular hydrogen bonds.     

Crystal structure of benzimidazolium dichromate

The X-ray crystal structure of benzimidazolium dichromate is determined. The compound C₁₄H₁₄Cr₂N₄O₇ is Triclinic in P-1 with a = 8.2722(8) Å, b = 10.0269(10) Å, c = 11.7001(11) Å, = 102.073(2)°, =100.483(2)°, = 67.288(2)°, V = 869.88(15) ų, D _calc = 1.734 g/cm³, and Z = 2. A dichromate ion connects two benzimidazolium rings via hydrgen bonds, as leads to face-to-face intramolecular aromatic stacking. The major force of crystal formation comes from hydrogen bonds, and an intermolecular hydrogen bridge is formed to connect two neighbored dichromate ions.     

Crystal and molecular structure of trans-bis(dodecylamine) bis(dimethylglyoximato)cobalt(III) nitrite

An octahedral geometry for the molecule of the title complex with very slight distortions around Co(III) is confirmed by single-crystal X-ray diffraction study. The molecular structure of the complex has been shown to contain two dodecylamine moieties in the trans orientations, two N-bonded dimethylglyoximato (DMG) groups and an uncoordinated nitrite ion.     

Crystal structure of 1-chloroanthraquinone

The X-ray crystal structure of 1-chloroanthraquinone is determined. The compound C₁₄H₇O₂Cl, is monoclinic in P2₁(#4) with a = 7.763(1), b = 3.973(2), c = 16.947(1) Å, = 95.13(1)°, V = 520.6(3) ų, D _calc = 1.548 g/cm³, and Z = 2. In the molecular structure, the Cl atom is obviously repelled by O(1). The major force of crystal formation comes from aromatic ring stacking and C–H-aromatic interaction.