The crystal structure of eudesma-4(15),7(11)-dien-8α, 12-olide: a sesquiterpene lactone fromTrattinickia rhoifolia Willd

The title compound, formula C₁₅H₂₀O₂, is orthorhombic, P2₁2₁2₁ witha=8.747(2),b=12.025(3),c=12.554(3)Å,Z=4, andD _m =1.32(2)g/ml. The structural analysis shows that the compound corresponds to eudesma-4(15),7(11)-dien-8,12-olide, a sesquiterpene lactone previously isolated fromAster umbellatus but whose crystal structure was unknown.     

Crystal structure of two oximes incis-pinane series

The structures of racemic 2-hydroxy-4-hydroxyiminopinan-3-one (1) and 3-hydroxyimino-cis-pinan-4-one monohydrate (2) have been determined by X-ray diffraction. The crystals of1 are monoclinic:P2₁/c, a=7.838(2),b=10.776(3),c=12.025(3) Å, =105.09(1)°,Z=4, room temp.; the crystals of2 are orthorhombic;P2₁2₁2₁,a=8.181(3),b=9.250(3),c=14.085(6)Å,Z=4, T=80K. Both structures were solved by direct methods, and refined toR=0.037 for 1920 reflections (1) and 0.032 for 1776 reflections (2). The absolute configuration of2 was not established. The hydroxyimine groups in both crystals and water molecules in2 participate in the network O–H...O of hydrogen bonds.     

The Crystal Structure of <Emphasis Type="SmallCaps">dl</Emphasis>-Lomenfloxacin Hydrate

Abstract  The dl-lomenfloxacin hydrate is an innersalt, which crystallizes in space group C2/c with cell parameters a = 22.897(10), b = 8.682(1), c = 18.365(2) ?, β = 93.633(9)°, V = 3,705(3) ?³ and Z = 8. The piperazinyl ring adopts a chair conformation, and the quinolone ring is essentially planar. The plane defined by C atoms of the piperazinyl ring is not coplanar with the quinolone ring. The carboxylate group shows two disorder parts, and is not coplanar with the quinolone ring, the dihedral angle between them is 113.8°. The disorder carboxylate group is split into two parts, the planes of which are skewed at the dihedral angles of 24.5 and 21.6° with the plane of the quinolone ring, respectively. The IR of the title compound is measured and studied. Index abstract  The crystal structure of dl-lomenfloxacin hydrate is determined by X-ray diffraction. The IR is measured and shows great differences from previous studies.      

Preparation,spectral studies,and X-ray crystal structures of (16S, 17R, 20S)-3-oxo-16-hydroxy-25-nor-lanostan-24-oic lactone (II) and (16S, 17R, 20S)-4,16-dihydroxy-25-nor-3,4-seco-lanostan-3,24-dioic acid dilactone (III)

The crystal and molecular structures of the title compounds have been determined by direct methods, and refined to a finalR of 0.059 forII and 0.046 forIII. Both molecules crystallize in space group P2₁2₁2₁. The cell dimensions forII area=10.096(5),b=11.255(3),c=20.300(7) Å;Z=4,D _x=1.188 g cm^–3, (MoK)=0.70 cm^–1, while the cell dimensions forIII area=7.346(1),b=10.470(3),c=30.546(5) Å;Z=4,D _x=1.212 g cm^–3, (MoK)=0.74 cm^–1. The rings of the triterpene skeletons aretrans-cis-trans-cis connected. The conformations of both molecules are discussed. Also the preparation and the spectral data of (17R, 20S)-3,16-dioxo-25-nor-lanostan-24-oic acid (V) and (17R, 20S)-3,16,24-trioxo-25-hydroxy-16,24-seco-lanostan-25-acetate (VI) are given.     

Crystal structure oftrans-tetrachlorobis[2-(2-1H-imidazolyl)-1H-imidazolium]cadmium(II), [Cd(H3biim)2Cl4]

The reaction between cadmium(II) chloride and 2,2'-bi-1H-imidazole (H₂biim) in an acidic solution affords [Cd(H₃biim)₂Cl₄] (H₃biim=2-(2-1H-imidazolyl)-1H-imidazolium) in 63% yield. The compound crystallizes in the triclinic space groupP1, wherea=8.072(2),b=8.100(2),c=8.593(2) Å, =75.89(2), =62.94(2), =63.29(1)°,V=446.4(2) ų, andZ=1. The central Cd atom exhibits an octahedral geometry composed of a Cl₄N₂ core. The Cd-N bond distance is 2.392(2) Å. Cd–Cl distances are 2.5919(9) and 2.671(1) Å.     

X-ray crystal and molecular structure of 2,3-dideoxy-4-thio-d-arabino-heptonic acid 1,4-lactone: a key intermediate for syntheses of 2′, 3′-dideoxy-4′-thio-l-nucleosides

The structure of 2,3-dideoxy-4-thio-d-arabino-heptonic acid 1,4-lactone has been determined by X-ray diffraction. Crystals of the compound are orthorhombic, space groupP2₁2₁2₁, with cell dimensionsa=11.555(5),b=10.451(5),c=9.604(5) Å, andZ=4. The diffraction experiment has allowed to assign the absolute configuration (4R, 5R, 6R) to the chiral centers of the molecule.     

Crystal structure and physical characterization of <Emphasis Type="Italic">N</Emphasis>-(3,3-dimethylbutyl)-<Emphasis Type="SmallCaps">l</Emphasis>-α-aspartyl-<Emphasis Type="SmallCaps">l</Emphasis>-phenylalanine,the hydrolysis product of neotame

The hydrolysis product of neotame, N-(3,3-dimethylbutyl)-l--aspartyl-l-phenylalanine (DMBAP), was crystallized from water as an anhydrate with a melting point at 197C with decomposition. Its crystal structure was determined by single crystal X-ray diffractometry. The crystal is orthorhombic with space group P2₁2_₁2₁ with Z=4 and one molecule per asymmetric unit. The cell constants are a=5.520 (2) Å, $b=10.608$ (5) Å and c= 31.92 (2) Å. The ¹³C solid-state nuclear magnetic resonance spectrum of DMBAP is compared with those of neotame monohydrate and neotame methanol solvate.     

Preparation,spectral studies and X-ray crystal structure of 1,3,5-triphenyl-1,5-pentanedione,C23H20O2

1,3,5-triphenyl-1,5-pentanedione, C₂₃H₂₀O₂, has been prepared and characterized by spectroscopic methods and single crystal X-ray analysis. Crystals are monoclinic, space groupP2₁/n, a=28.124(4),b=5.997(1),c=10.434(1)Å, -98.42(1)Å,Z=4. The structure has been refined to a finalR-value of 0.040 for 1625 reflections withF _o>3(F _o). The compound contains the two carbonyl groups in a mutuallycis arrangement.     

Structure of malagashanine,a new alkaloid with chloroquine-potentiating action

The molecular structure of malagashanine (C₂₃H₃₀N₂O₄), a new alkaloid occurring in MadagascanStrychnos species and showing chloroquine-potentiating action, has been determined by single crystal X-ray diffraction. The crystals, in the form of a 11 acetone solvate, are monoclinic, space group P2₁, witha=10.328(2),b=10.554(6),c=11.490(5)Å, =96.67(2)⁰,Z=2. Refinement based on 3650 reflections measured at 294K yieldedR=0.045. The X-ray analysis shows that the ring system in malagashanine differs from that in alkaloids of the strychnobrasiline type in containing only five-and six-membered rings. Thermal analysis of the solvate indicates that the acetone molecules are firmly held in the crystal and the X-ray analysis reveals that they are trapped in crystal voids. Only van der Waals forces and C–H...O hydrogen bonds stabilize the crystal structure.     

Synthesis,crystal and molecular structure and vibrational characterization of N,N-dimethyl-oxathioamidate monohydrate

The title compound (SO₂NC₄H₆) has been prepared and characterized by X-ray diffraction and infra-red and Raman spectra. The structure has been refined using single-crystal X-ray diffraction data measured at 295K [MoK-radiation with =0.71073 Å]. The crystals are monoclinic, space groupP2₁/n,Z=4,a=6.240(2),b=6.786(2),c=19.988(1)Å, =108.47(2)°,V=802.8(7)ų.D _calc.=1.566 Mg m^–3,F(000)=392, =8.582 cm^–1. The final agreement factors for 1906 observed refections [I>3(I)] were:R=0.030 andR _w=0.043. The dihedral angle between de C–C–S–N plane and the C–C–O–O plane is 88.31(4). The potassium atom within the title compound structure has a slightly distorted trigonal bipyramidal coordination. Infrared and Raman spectra of the normal CH₃/CD₃ and H₂O/D₂O isotopes and the waterfree compounds at different temperatures made it possible to perform isotopes complete vibrational analysis and clearly shows the very special hydrogen bonded water molecule in the crystal.     

Solid-state formation of an inclusion compound of cholic acid withp-toluidine

Cholic acid undergoes solid-solid reactions with some aromatic molecules to form inclusion compounds. Simple shaking of a mixture of powdered cholic acid andp-toluidine results in formation of the 11 (host:guest) inclusion compound which has the same structure as that formed by conventional crystallization methods: monoclinic space groupP2₁ witha=13.577(4),b=8.078(2),c=14.182(6) Å, =114.42(3)°,Z=2 andR ₁=0.061 for 2680 unique reflections.     

Crystal and molecular structure of benzoyl-l-leucyl-glycine ethyl ester (l-LEUGLY)

The crystal structure of the dipeptide derivative benzoyl-l-leucylglycine ethyl ester has been determined by direct methods (Multan 78), and refined by fullmatrix least squares toR=0.092 for 1638 reflections;I>3(I), CuK radiation. The space group isP2₁2₁2₁,a=20.679(7),b=16.440(6),c=11.034(5) Å,Z=8. Disorder observed in the ethyl ester and leucyl side-chains of the two independent molecules per asymmetric unit probably accounts, at least partially, for the weak diffracting power of the crystals. Both molecules exhibit markedly coiled hydrogen-bonded conformations. An attempt was made to obtain improved hydrogen bond geometry by the use of neutron diffraction data.     

The structure of dimethylcrocetin

The structure of dimethylcrocetin (DMCRT), prepared by alkaline hydrolysis in methanol of the glucosidic carotenoids extracted from the stigmata of theCrocus sativus L. flowers, has been determined. The molecule has the all-trans configuration and is planar forming a long conjugated system. The C–O bond length values of the two ester groups are shortened as expected. The compound (C₁₁H₁₄O₂)₂ crystallizes in the orthorhombic space group Pbcn witha=12.5907(7),b=7.5639(5) andc=21.963(2)Å. Dimethylcrocetin has characteristic Infrared absorptions at 1697 cm^–1 (C=O) and 1229 cm^–1 (C–O) and characteristic Raman vibrational modes at 1542 cm^–1 (C=C) and 1166 cm^–1 (C–C).     

Structure and spectral properties of (O-Cyclohexyldithiocarbonatio-S,S′) bis(triphesnylphosphine) copper(I) complex

The complex [(C₆H₁₁OCS₂)(PPh₃)₂Cu], was synthesized and characterized using IR, UV, and ¹H NMR. The crystal and molecular structure has been determined by X-ray diffraction. The yellow crystal of the complex is triclinic of space group , with parameters a=10.370(2)Å, b=13.530(3)Å, c=14.640(3)Å, =92.60(3)°, =108.00(3)°, =97.70(3)°, and Z=2. In the complex, the central Cu atom is in a distorted tetrahedral environment and chelated by two phosphorus atoms of the TRIPHOS and two sulfur atoms from the O-cyclohexyldithiocarbonate. The cyclohexane ring adopts a chair conformation. The thermal analytical data indicate that the complex begins to decompose at 101°C and stop at 360°C , leaving CuS. IR, UV, and NMR results supported the crystal structure.     

Altering Hydrophilic and Hydrophobic Region via O–H···O and C–H···O Hydrogen Bonds and van der Waals Forces in Solagenin 6- O -( β -d -quinovopyranoside) Methanol Solvate Monohydrate

Abstract  The title compound, C₃₃H₅₂O₈·CH₃OH·H₂O, isolated from Solanum torvum, consisted of a solagenin 6-O-(β-d-quinovopyranoside) molecule, a methanol solvate and a hydrate. The six-membered rings A, B, C, F and G have chair conformations. The five-membered ring D adopts a half-chair conformation and the ring E adopts an envelope conformation. The A/B, B/C and C/D ring junctions are trans, whereas the D/E junction is cis. The molecular packing appeared to be established by alternation of a hydrophilic region involving methanol molecules, water molecules and the β-d-quinovopyranoside of the steroid nucleus via the classic O–H···O hydrogen bonds and a hydrophobic region consisted by the other part of the steroid nucleus via weak C–H···O hydrogen bonds and van der Waals forces. Graphical Abstract  The molecular packing of the title compound appeared to be established by alternation of a hydrophilic region involving methanol molecules, water molecules and the β-d-quinovopyranoside of the steroid nucleus via the classic O–H···O hydrogen bonds and a hydrophobic region consisted by the other part of the steroid nucleus via weak C–H···O hydrogen bonds and van der Waals forces.      

The crystal structure of 2-amino-5,5′-bis(β-cyanoethyl)-1,2-pyrrolenineN-oxide monohydrate

2-Amino-5,5-di(-cyanoethyl)-1,2-pyrrolenineN-oxide monohydrate, C₁₀H₁₄N₄O·H₂O, crystallizes from MeCN in space group P2₁2₁2₁ witha=7.0007(5),b=8.2998(6),c=20.8418(13) Å,V=1211.0(2) ų,Z=4. The structure was refined toR=0.034 andR _w=0.044 for 2325 observed reflections. The pyrrolenine ring adopts a nearly planar conformation, with maximum deviation from planarity 0.089(2) Å. The N–O distance is 1.345(2) Å. The water molecule bridges two pyrrolenine molecules via hydrogen bonds to theirN-oxide oxygen atoms, and also accepts a hydrogen bond from the NH₂ group of another pyrrolenine molecule.     

D-β,β-dimethylcysteic acid,its preparation,structure, and spectroscopic properties

The X-ray crystal structure ofd-,-dimethylcysteic acid, C₅H₁₁NO₅S, has been determined. The compound is monoclinic, space groupP2₁₄ (No. 4), with cell dimensionsa=8.133(1),b=8.094(1),c=6.3138(7) Å,=96.36(1)° andZ=2. The structure was solved by Patterson and electron density difference methods and refined toR=0.025,R _w=0.022 for 1081 reflections. Bond lengths and angles do not differ from those in similar structures. The crystal is held together by intermolecular hydrogen bonds. The vibrational spectra have been recorded and assigned and the¹ H and¹³C NMR spectra were measured.     

Structure of 17α-methyl-testosterone semihydrate,C20H30O2·1/2 H2O

The crystal structure of 17-methyltestosterone hemihydrate, C₂₀H₃₀O₂·1/2H₂O, has been determined:M _r =312.5, space groupP2₁2₁2₁2₁,a=6.374(2),b=12.807(2),c=43.398(5)Å,V _c =3543(2)ų,Z=8,D _x =1.172 mg^–3, CuK radiation ( = 1.54184 Å),(CuK)=5.5 cm^–1,F(000)=1376. The structure was solved usingMultan. The final conventionalR=0.053 (R _w =0.052) for 3634 reflections. The structure contains two crystallographically independent molecules in the asymmetric part of the unit cell that have almost identical geometry.     

X-ray structures of two methoxybenzo[b]thiophenes

The crystal and molecular structures of two methoxybenzo[b]thiophenes have been determined by three-dimensional, single-crystal X-ray diffractometry. Both 3-(4-hydroxy-3, 5-dimethoxybenzoyl)-2-(4-methoxyphenyl)-6-methoxybenzo[b]thiophene and 3-(2,6-dimethoxybenzoyl)-2-(4-methoxyphenyl)-6-methoxybenzo[b]thiophene (hereafter referred to asI andII, respectively) crystallize in the monoclinic centrosymmetric space groupP2₁/n (No. 14, C _2h ⁵ ) with four formula units-per cell witha=6.866(1),b=28.638(2),c=11.830(2) Å, and =105.52(1)° anda=9.328(1),b=7.977(1),c=29.650(4) Å, and =97.87(1)°, respectively. The phase problems were solved by direct methods and the respective final full-matrix least-squares refinements converged toR=0.046 and 0.031. The structures differ in the positioning of the dimethoxy groups of the benzoyl ligands and the addition of a hydroxyl group inI. The molecules in the crystal lattice are held together by van der Waals forces plus the addition of hydrogen bonding in compoundI. Selected bond distances and angles and torsion angles are tabularized.     

Molecular rearrangement of photoparthenin by BF3-etherate-acetic acid complex: X-ray crystal structure of a novel product

The structure of a novel compound,Iupac name: bicyclo [2.4.0]-octa-1,3-dimethyl-2,3-pentan-9-methylene-8, 10-butan-diolide, which resulted on treatment of photoparthenin with BF₃-etherate acetic acid, has been established uniquely by X-ray crystallography. C₁₅H₁₈O₄ is orthorhombic, space group P2₁2₁2₁, with the cell dimensionsa=8.444(1),b=9.964(2),c=16.239(2) Å,V=1366.3(2) ų,Z=4,M _r =262.3,D _o=1.29,D _x=1.28 g cm^–3, F(000)=560,T=293K,R=0.065 for 818 observed reflections. -lactone ring has a skew-boat, -lactone ring has an envelope, and the remaining six-membered ring has a distorted chair conformation. The four-membered ring is nonplanar. There are two intramolecular and one intermolecular short C-HO interactions 2.819, 2.834, and 3.259 Å, respectively, which stabilize the crystal structure.N.C.L. Communication No. 4583.