The Crystal and Molecular Structure of Mesogenic Malonates (II)

The crystal and molecular structures of three diethyl-2-{n-[4-(4-nitrophenylazo)-phenoxy]alkyl}malonate with n = 5 (5 PhNO₂), 7 (7PhNO₂), 9 (9 PhNO₂) and an analogous diethyl-2-[4(4-cyanophenylazo)phenoxy]pentylmalonate (5 PhCN) have been determined with CuK_a or MoK_a: 5 PhNO₂: a = 8.007(6) Å, b = 11.960(8) Å, c = 13.516(9) Å, α = 77.10(6)°, β = 81.80(5)°, γ = 83.15(5)°; R = 0.053; 7PhNO₂: a = 8.074(4) Å, b = 11.592(5) Å, c = 14.422(7) Å, α = 87.43(3)°, β = 82.46(3)°, γ = 85.43(3)°; R = 0.072; 9 PhNO₂: a = 5.520(5) Å, b = 13.628(9) Å, c = 20.220(11) Å, α = 100.02(4)°, β = 95.49(4)°, γ = 101.02(4)°; R = 0.042; 5 PhCN: a = 8.018(6) Å, b = 11.960(8) Å, c = 13.566(7) Å, α = 77.82(5)°, β = 81.89(5)°, γ = 82.69(5)°; R = 0.067 (isotropically refined). All these structures belong to the triclinic space groups P1 . The arrangements of the molecules in the crystal of the homologous series of nPhNO₂ suggest two different types of packing independent of n even, odd or large, small. 5 PhCN represents an isomorphous structure to 5 PhNO₂. Isomophism between 7 PhNO₂ and 7 PhCN was confirmed by cocrystallization of these two compounds whose crystal structure was also determined.     

The Crystal and Molecular Structure of an Antidepressant Drug (Isocarboxazid)

The crystal arid molecular structure of 5-methyl-3-isoxazole carboxylic acid 2-benzylhydrazine (isocarboxazid, C₁₂H₁₃N₃O₂), an antidepressant drug, has been determined by X-ray diffraction method and IR analysis. The compound crystallizes in the monoclinic space group P2₁/c, with a = 6.376(1), b = 14.131(1), c = 13.256(1) Å, β = 99.75(1)°. The structure has been solved by using SIR program and refined to R = 0.048. The benzene and isoxazoles rings are not coplanar and have a dihedral angle of 167.7(5)° between their respective planes. Some of the bond lengths and angles found in the molecule are distorted due to π-electron delocalization and strain. The infrared spectrum of isocarboxazid has been also reported and assignments have been suggested for some characteristic bands. These assignments were confirmed by X-ray analysis.     

The Crystal and Molecular Structure of the Sesquiterpenoid Silerin (Trilobolide)

For the title compound a guaianolide structure is shown by X-ray analysis. Only the relative configuration of the molecule could be established.     

The Crystal and Molecular Structure of the Complex Diaquatetrakis(imidazole)copper(II) Terephthalate Crystal Structure Containing Cu(II) Him and TA

The title compound has been synthesized and its crystals structure determined at room temperature. MW = 536.01, monoclinic, space group C2/c, Z = 4, a = 22.193(5) Å, b = 8.038(2) Å, c = 15.699(4) Å, β = 119.64(2)°. The crystal structure consists of repeated [Cu(Him)₄(H₂O)₂] (Him = imidazole) cations and non-coordinated terephthalato dianions. The copper(II) ion displays an elongated octahedral coordination being linked to the four nitrogen atoms of the four imidazole ligands and to the two oxygen atoms of the two water molecules. The terephthalato dianions are hydrogen bonded to the four water molecules and four imidazole groups.     

The Molecular and Crystal Structure of p-methyl-phenyl-glyoxyacid-p-chloranilide

Using X-ray crystal structure analysis of the title compound the positions of all the atoms (including all H atoms) in the monoclinic unit cell with the parameters a = 13.90₀ Å, b = 5.13₈ Å, c = 17.95₆ Å and β = 91.05° and the space group P 2₁/n were localized. The existence of an intramolecular N—H(N)…︁ O(1)-bridge was inferred, whose H-bridge acceptor predominantly is the π-electron density of the carbonyl group. At the same time the H(N) atom participates in the intermolecular bridge N H(N)…︁ O′(1) to the symmetry-equivalent neighbouring molecule. H-bridge-like interactions of the two phenyl hydrogen atoms H(6) and H(15) to the carbonyl oxygen O(2) have also been inferred from the torsion angles.     

The Crystal and Molecular Structure of 1,18-dibromooctadecane

The crystal and molecular structures of 1,18-dibromooctadecane are determined precisely by X-ray diffraction method. The results obtained are as follows: empirical formula, C₁₈H₃₆Br₂, formula weight Mr = 412.27, crystal system, monoclinic, space group, P2₁/n, lattice parameters, a = 5.496(1), b = 5.403(1), c = 34.374(4) Å, β = 94.50(1)°, volume of unit cell, V = 1017.6(3) ų, Z value, Z = 2, calculated density, D_x = 1.346 g/cm³, wave length of X-ray, λ(CuKα) = 1.5418 Å, absorption coefficient, μ(CuKα) = 49.64 cm⁻¹, F(000) = 428.00, temperature, T = 293 ± 1 K, R factor, R = 0.052, weighted R factor, R_w = 0.078 for 1019 unique observed reflection [I > 3σ (I)]. There are no unusual bond distances or angles. The structure obtained here is quite similar to that of 1,12-dibromododecane.     

The Crystal and Molecular Structure of Mesogenic Malonates

The crystal and molecular structures of diethylene-6-[4-(4′-nitrophenylazo)phenoxy]dodecylmalonate (12 PhNO₂) and -propylmalonate (3 PhNO₂) were determined with CuK_α to a = 19.235(5) Å, b = 7.620(1) Å, c = 22.400(4) Å; α = 90°, β = 103.27(1)°, γ = 90°; space group P2₁/c for 12 PhNO₂ and a = 6.797 (6) Å, b = 7.756 (8) Å, c = 22.74(2) Å; α = 81.48(7)°, β = 88.29(7)°, γ = 68.10(9)°; space group P1 for 3 PhNO₂. Refinement with 1130 observed reflections (> 3σ) for 12 PhNO₂ and 1615 for 3 PhNO₂ leads to R (12 PhNO₂) = 5.8% and R(3 PhNO₂) = 4.4%. The molecular conformation in the crystalline state is the most extended trans conformation for both compounds. On rapidly cooling from the isotropic melt, 12 PhNO₂ shows a smectic A-phase. In agreement with prior investigations on polar mesogens, the molecules arrange in an antiparallel packing. The azo-mesogen is nearly coplanar with the alkoxy spacer up to the branching atom. The low molecular weight malonates investigated may serve as model compounds for side-group liquid crystalline polymers.     

The Crystal and Molecular Structure of 1,8-Dioxo-9- (o-nitrophenyl)-1,2,3,4,5,6,7,8-octahydroxanthene

The crystal structure of the title compound is described. The compound crystallizes in monoclinic space group P21/a with Z=4. The unit cell dimensions are a = 10.809(2), b = 9.998(2) and c = 14.855(3) Å, V = 1592(1) ų, D_cal = 1.399 g/cm³. The central ring of the octahydroxanthene moiety is slightly folded and the two outer rings are in sofa conformations. Due to the p-conjugation there is an electron delocalized stretch. The phenyl ring of the 2-nitrophenyl substituent is perpendicular to the octahydroxanthene ring system.     

Synthesis,Crystal and Molecular Structure of Cd2(sacch)4(Im)4

The title compound has been synthesized and its crystal structure determined at room temperature. Cd₂(Sacch)₄(Im)₄ F.W. = 1225.83, monoclinic. Space group: C2/c, Z = 4, a = 20.065(3) Å, b = 11.164(4) Å, c = 20.697(6) Å, β = 94.69(5)°, The coordination polyhedron of Cd(II) correspond to a five-coordinate trigonal-bipyramid. In the title complex, two of the saccharin groups act as monodentate ligands. The other two act as bidentate ligands. The two Cd(II) ions are bridged by the two bidentate saccharin groups and the distance is 4.75 Å.     

Crystal and Molecular Structure of Piperidinium-acet-m-Cl-anilide-chloride

Piperidinium-acet-m-Cl-anilide-chloride crystallizes in the orthorhombic space group Pca2₁ with 4 formula units C₁₃H₁₈ON₂Cl₂ in the unit cell. The lattice parameters are a = 10.348 Å, b = 12.280 Å and c = 11.335 Å. The crystal structure was determined by the heavy atom method and refined by least-squares procedures to the conventional R = 0.045. Bond lengths, bond angles and the conformation of the drug molecule were determined. Cl⁻ ions are linked to the molecules by hydrogen bonds forming chains together with iones and molecules related by the a-glide plane.     

Crystal and Molecular Structure of Desmodin

The crystal structure of the title compound has been determined from X‐ray diffraction. The compound crystallizes from benzene in the orthorhombic system, space group P2₁2₁2₁, with unit cell parameters: a = 8.485(2), b = 9.816(2), c = 22.597(4) Å, Z = 4, V = 1881.9(7) ų. The structure was determined by direct methods and refined to a final R‐factor of 0.04. Six membered rings B and E are planar. Ring A and ring C are in slightly distorted sofa conformation. Ring D is in envelope conformation. The structure is stabilised by weak intermolecular C‐H...O hydrogen bonds.     

Crystal and Molecular Structure of Anion Radical Salt (N-Me-DABCO)(TCNQ)2

Crystallography Reports - An anion radical salt of 7,7,8,8-tetracyanoquinodimethane (TCNQ) with the complex composition (N–Me–DABCO)(TCNQ)2 (1) has been synthesized. The crystal...     

Crystal and Molecular Structure of a co-Crystal of 5-Nitrimino-1,4H-1,2,4-triazole with Dimethyl Sulfoxide

Crystallography Reports - The structure of the labile co-crystal of 5-nitrimino-1,4Н-1,2,4-triazole with dimethyl sulfoxide was determined by X-ray diffraction. It was established that the...     

Synthesis,Characterization, Crystal and Molecular Structure Analysis of 2,6-Dimethyl-3-acetyl-5-carbomethoxy-4-(3-nitrophenyl)-1,4-dihydropyridine

Abstract  A novel unsymmetrical dihydropyridine, possessing carboxymethyl and carbomethoxy groups at C(3) and C(5), respectively, has been produced using a modified Hantzsch synthesis, under solvent free conditions, in a domestic microwave oven. The product obtained was characterized by spectroscopic techniques and finally confirmed by X-ray diffraction studies. The title compound C₁₇H₁₈N₂O₅ crystallizes in the monoclinic system in the space group P2₁/c with cell parameters a = 12.860(2) ?, b = 7.4950(6) ?, c = 16.734(3) ?, β = 94.436(3)°, Z = 4 and V = 1608.1(4) ?³. The 1,4-dihydropyridine ring in the structure is in a flattened boat conformation. The molecule possesses a chiral center at C4. The 3-nitrophenyl ring is nearly orthogonal to the 1,4-dihydropyridine ring. The carbonyl groups at C3 and C5 are oriented in −antiperiplanar and +synperiplanar conformations, respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O and C–H···O. Index Abstract  A novel unsymmetrical dihydropyridine, possessing carboxymethyl and carbomethoxy groups at C(3) and C(5) respectively, has been produced using a modified Hantzsch synthesis, under solvent free conditions, in a domestic microwave oven. The product obtained was characterized by spectroscipic techniques and finally confirmed by X-ray diffraction studies. The title compound C₁₇H₁₈N₂O₅ crystallizes in the monoclinic system in the space group P2_1/c with cell parameters a  =  12.860(2) ?, b  =  7.4950(6) ?, c  =  16.734(3) ?, β = 94.436(3)°, Z = 4 and V = 1608.1(4) ?³. The 1,4-dihydropyridine ring in the structure is in a flattened boat conformation. The molecule possesses a chiral center at C(4). The 3-nitrophenyl ring is nearly orthogonal to the 1,4-dihydropyridine ring. The carbonyl groups at C(3) and C(5) are oriented in −antiperiplanar and +synperiplanar conformations respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O and C–H···O.

The Crystal and Molecular Structure of 4'-Cyanophenyl-4-n-Pentylbenzoate

The crystal and molecular structure of the title compound with the formula C₅H¹¹—C₆H₄—COO—C₆H₄—CN (CPPB) has been determined by X-ray diffraction methods. CPPB crystallizes in the monoclinic space group P2₁/n with eight molecules in a unit cell of dimensions a = 15.268(2) Å, b = 9.165(1) Å, c = 24.031(3) Å, β = 94.67(1)°. The structure has been solved by direct methods and refined to an R value of 0.070.

The CPPB molecules adopt a stretched form and are packed in an approximate parallel imbricated mode, the molecular long axes making an angle of about 5° with the crystal c axis. The molecular geometry and packing are discussed in relation to the mesomorphic behavior of CPPB.     

Crystal and Molecular Structure of an Acridinedione

The title compound, 10‐(4‐hydroxybenzoylamino)‐3,4,6,7,9,10‐hexahydro‐1,8‐(2H,5H)‐acridinedione monohydrate,C₂₀H₂₂N₂O₄.H₂O, consists of partially hydrogenated acridine moiety with one benzoylamino substituent on the central ring. The compound crystallizes in monoclinic system with P2₁/c space group and the unit cell constants are: a = 11.142(4), b = 12.266(2), c = 13.320(2) Å; β = 91.76(2)° and V = 1819.6(8) ų.The central ring (B) adopts boat and the outer rings (A and C) adopt sofa conformations. The water molecule takes part in OW‐H...O and N‐H...OW hydrogen bond formation with acridinedione and benzoylamino group. The oxygen atom O1 interacts through O–H...O bond with the hydroxyl group and in a head‐to‐tail link up of molecules that results in the formation of an infinite “supra molecular“ chain.