Conformational polymorphism of N-(4-butoxyphenyl)-4-(4′-nitrophenyl)-2-thiazolamine

Crystallography Reports - The molecular and crystal structures of three concomitant polymorphic modifications of N-(4-butoxyphenyl)-4-(4′-nitrophenyl)-2-thiazolamine are investigated by X-ray...     

The Synthesis and Crystal Determination of 3-Hydroxy-4-(4-methoxyphenyl)-5-(2-nitrophenyl)furan-2(5H)-one

Abstract  

The title compound, C₁₇H₁₃NO₆, was synthesized and structurally characterized by elemental analysis, MS, ¹H NMR and single crystal X-ray diffraction. It crystallizes in monoclinic system space group C 2/c with a = 27.981(6) ?, b = 12.996(3) ?, c = 8.0900(16) ?, β = 91.06(3)°, V = 2941.4(10) ?³, Z = 8, R ₁ = 0.0675, wR ₂ = 0.1626, and T = 298(2) K. The X-ray structure determination revealed that the center furanone ring is nearly coplanar with p-methoxybenzene ring and forms a dihedral angle of 87.2(1)° with the nitrobenzene ring. O–H···O Intermolecular hydrogen bonds link pairs of molecules into centrosymmetric dimers, making a graph set motif of R ₂²(10). The dimers are further assembled into a chain of edge-fused R ₄⁴(34) rings running along the [001] direction. The final three-dimensional supramolecular architecture is stabilized by weak π–π interactions.     

Molecular and crystal structures of 2-amino-5-benzoyl-4-(2-nitrophenyl)-3-cyano-4,5-dihydrothiophene

The crystal structure of 2-amino-5-benzoyl-4-(2-nitrophenyl)-3-cyano-4,5-dihydrothiophene is determined by X-ray diffraction analysis. The unit cell parameters are as follows: a = 10.878(2) Å, b = 12.890(3) Å, c = 13.539(4) Å, α = 108.15(2)°, β = 99.26(2)°, γ = 107.13(2)°, V = 1656(2) ų, d _calcd = 1.410 g/cm³, Z = 4, and space group P1ˉ. The molecules occupy two systems of independent positions in the crystal. Similar to the compounds studied earlier in this series, the o-nitrophenyl substituent has a synperiplanar orientation relative to the hydrogen atom at the C(4) atom of the heterocycle. __________ Translated from Kristallografiya, Vol. 45, No. 2, 2000, pp. 282–285. Original Russian Text Copyright ? 2000 by Nesterov, Kuleshova, Samet, Shestopalov.     

Crystal structure of the molecular complex of 3-[1-(4-nitrophenyl)-3-oxobutyl]-4-hydroxychromen-2-one with ethanol

The crystal structure of 2,3H-2-methyl-4-(4-nitrophenyl)-5-oxobenzopyrano[3,4-e]dihydropyran-2-ol is investigated using X-ray diffraction. The unit cell contains an ethanol molecule that forms hydrogen bonds with O-H and C-O groups of two molecules of the main compound and acts as a proton donor and a proton acceptor in these hydrogen bonds. Owing to these interactions, infinite chains are formed in the crystal. The crystallographic data for the structure of C₁₉H₁₅NO₆·C₂H₅OH (M = 399.39) are as follows: the crystals are triclinic, space group P1, a = 5.5340(3) Å, b = 8.0109(4) Å, c = 11.0112(5) Å, α = 88.773(2)°, β = 84.788(2)°, γ = 79.958(2)°, and Z = 1.     

Preparation and studies of new crystals in the K3H(SO4)2-(NH4)3H(SO4)2-H2O system

To elucidate the effect of isomorphic substitution on the kinetics of phase transitions, single crystals of (K _x (NH₄)_1?x ) _m H _n (SO₄)_{(m + n)/2} · yH₂O solid solutions are grown from the K₃H(SO₄)₂-(NH₄)₃H(SO₄)₂-H₂O system, whose end members are known to undergo superprotonic phase transitions of fundamentally different kinetics. The chemical composition of the single crystals grown is determined by energy dispersive X-ray microanalysis. The thermal and optical behavior of (K,NH₄)₉H₇(SO₄)₈ · H₂O single crystals is studied in the temperature range 295–420 K and the crystal structure at 295 K is determined. A comparison of the results of the studies with data for crystal K₉H₇(SO₄)₈ · H₂O published earlier shows that the substitution of ammonium for potassium atoms lowers the temperature of the structural phase transition by 8 K.     

Crystal Structure of (E)-1-(((3-nitrophenyl)imino)methyl)naphthalen-2-ol

Crystallography Reports - Formation of the title Schiff base compound (E)-1-(((3-nitrophenyl)imino)methyl)naphthalen-2-ol, C17H12N2O3 (1) was achieved by the condensation of...     

Structure of 2-acetoxy-3-(3-methoxy-4-acetoxy-5-chlorophenyl)-propenoic acid

2-Acetoxy-3-(3-methoxy-4-acetoxy-5-chlorophenyl)-propenoic acid 2 was synthesized from the azlactone of 5-chlorovanillin and its structure confirmed by X-ray crystallography and nuclear magnetic resonance methods. Compound 2 crystallized with a molecule of acetic acid in the P-1(#2) space group (Z = 2) and with cell dimensions a = 6.303(2), b = 9.779(1), c = 15.528(3) Å, = 101.46(2), = 100.71(2) and = 90.21(2)°. This study reveals the formation of an -acetoxy propenoic acid with a trans extended side acid side chain conformation. The ¹H and ¹³C NMR spectral values of 2 also show the existence of the enolic ester in solution.     

X-ray crystallography of methyl (6-amino-5-cyano-2-methyl-4-(2-nitrophenyl)-4<Emphasis Type="Italic">H</Emphasis>-pyran)-3-carboxylate

The organic carbonitrile namely methyl (6-amino-5-cyano-2-methyl-4-(2-nitrophenyl)-4H-pyran)- 3-carboxylate is synthesized via one-pot multi-component reaction at room temperature using commercially available urea as inexpensive and environmentally benign organo-catalyst and its crystal structure is determined by X-ray technique. The crystals are monoclinic, sp. gr. C2/c, a = 12.3069(8) Å, b = 9.7023(7) Å, c = 24.812(2) Å, β = 94.862(6)°, Z = 8. The dihedral angle between pyran and phenyl rings is 87.8(1)°; the pyran ring is almost planar The dihedral angle between the mean planes of phenyl ring and nitro group is 44.4(2)°. The crystal structure is stabilized by N?H···N and N?H···O hydrogen bonds. In addition, C?H···π interactions are also observed in the crystal structure.     

Synthesis and Molecular Structure of 2-(4-Chlorophenyl)-3-(phenyl-amino)-5-(thiophen-2-ylmethylidene)-3,5-dihydro-4H-imidazol-4-one

Crystallography Reports - 2-(4-Chlorophenyl)-3-(phenylamino)-5-(thiophen-2-ylmethylidene)-3,5-dihydro-4H-imidazol-4-one, C20H14N3OSCl was synthesized and its crystal structure was determined by...     

Synthesis and Crystal Structures of 4-(3-Nitropyridin-2-ylamino)phenol and 4-(3-Aminopyridin-2-ylamino)phenol

Abstract  

The title compounds, 4-(3-nitropyridin-2-ylamino)phenol (I) and 4-(3-aminopyridin-2-ylamino)phenol (II), are two intermediates for the synthesis of a potential antitumor agent ABT-751. The reaction of 4-aminophenol with 2-chloro-3-nitropyridine yielded I which was converted into II by reduction. Instead of the Pd/C catalytic hydrogenation described in many literature, reduction with cheap sodium sulfide in aqueous media was utilized for shorting the reaction time and simplifying the operation. The crystal structures of the resultant compounds were determined by single-crystal X-ray diffraction. The compound I is crystallized in P2₁/c space group of monoclinic system, with a = 11.5236(19) ?, b = 8.7389(17) ?, c = 10.684(3) ? and α = 90.00°, β = 107.76(3)°, γ = 90.00°. The compound II is crystallized in Cc space group of monoclinic system, with a = 10.688(2) ?, b = 14.2181(18) ?, c = 7.9836(15) ? and α = 90.00°, β = 125.801(7)°, γ = 90.00°. In both crystal structures, the intermolecular N–H–O and O–H–N hydrogen bonds link the molecules, which effectively stabilize the structures.     

2-甲基4-(4-(吡啶-3-乙炔基)苯基)-3-丁炔-2-醇的合成及晶体结构

由1,4-二碘代苯出发,经过两步Sonogashira偶联反应合成了标题配合物2-甲基4.(4-(吡啶-3-乙炔基)苯基)-3-丁炔-2-醇.通过1H NMR、13C NMR核磁共振、Ⅹ-射线单晶衍射等手段对化合物的结构进行了表征.结果表明,该化合物晶体属于单斜晶系,空间群为P21/c.晶体学参数:a=3.3321 (4) nm,b=1.00539(11) nm,c=0.89158(10) nm,α =90.00°,β=92.442(2)°,y=90.00°,V=2984.2(6) nm3,Z =4.     

Synthesis and X-ray structure of 3-(4-methyl phenyl)-2-(4-biphenyl)-1,3-thiazolidin-4-one

The title compound (C₂₂H₁₉NOS) was synthesized, characterized and structure was determined by X-ray diffraction method. It crystallizes in the monoclinic space group P2₁/c with cell parameters a = 22.181(2) Å, b = 6.0760(4) Å, c = 13.349(3) Å, = 95.615(3)^, and {Z = 4}. The final residual factor is 0.0625 for 1724 reflections with I > 2(I). 4-thiazolidinone ring moiety shows twisted conformation.     

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 growth of single crystals of langbeinites Rb2Cd2(SO4)3, Tl2Cd2(SO4)3, K2Co2(SO4)3, and their phase transitions

Single crystals of dicadmium dirubidium sulphate and dicadmium dithallium sulphate have been grown from non-stoichiometric aqueous solutions by various methods. Optical and thermal properties in the vicinity of their phase transitions have been studied. Polycrystalline samples of dicobalt dipotassium sulphate have been prepared using Bridgman method. Optical and specific heat measurements have shown a new phase transition at −148°C.     

Synthesis,Crystal Structure,Spectroscopic and Electronic Properties of (E)-Trans-2-(2-(Biphenyl-4-ylmethylene)Hydrazinyl)-4-(3-Methyl-3-Phenylcyclobutyl)Thiazole

Abstract  

A new compound of (C₂₇H₂₅N₃S) has been synthesized and characterized by ¹H NMR, ¹³C NMR, IR, UV-Visible spectroscopy, and single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2₁/c and crystals of (I) were found approximately 0.5:0.5 ratio to be twinned. The crystal structure is stabilized by N–H···N inter molecular hydrogen bonding. In addition to the molecular geometry and dimeric structure from X-ray experiment, the optimized molecular geometry for monomer and dimer, vibrational frequencies, atomic charges distribution, and total energies of the title compound in the ground state have been calculated using ab initio method. Density Functional Theory (B3LYP) and Hartree-Fock (HF) methods with basis sets 6-31G(d, p) and 3-21G were used in the calculations. Calculated frequencies are in good agreement with the corresponding experimental data. UV-Vis absorption spectra of the compound have been ascribed to their corresponding molecular structure and electrons orbital transitions.     

Synthesis, characterization, and structural analysis of ethyl (2Z)-3-(4-chlorophenyl)-2-cyano-3-(methoxyamino)prop-2-enoate

Ethyl (2Z)-3-(4-chlorophenyl)-2-cyano-3-(methoxyamino)prop-2-enoate was prepared by reacting the lithium salt of ethyl cyanoacetate with (Z)-O-methyl-4-chloroben-zohydroximoyl fluoride. This compound crystallizes in space group Pbca,with lattice constants a=7.5740(15) ?, b=11.337(2) ?, and c=30.424(5) ? at 110 K. Characterizations include spectrometric identifications employing IR, UV, and ¹H and ¹³C NMR. The compound exists in the solid as the enamine tautomer, with the cyano group cis to the 4-chlorophenyl group (the Z configuration). The C=C and C–N bond distances are 1.3930(16) ? and 1.3278(16) ?, respectively. The N–H group forms a bifurcated hydrogen bond with acceptors C=O (intramolecular) and C≡N (intermolecular).Supplementary material CCDC-289444 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, by e-mailing data_request@ccdc.cam.ac.uk, or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; Fax: +44(0)1223-336033.     

Crystal structure of N-(4-nitrophenyl)-N-phenylsulfonamide

The crystal structure of N-(4-nitrophenyl)-N-phenylsulfonamide (C₁₈H₁₄N₂O₄S), a derivative of sulfonamide, has been determined by X-ray diffraction method using CuK radiation. The compound crystallizes in the monoclinic space groupP2₁/n, witha=24.463(1),b=5.745(2),c=11.428(3)Å and=94.39(2)°. The structure was solved by direct methods and refined by full-matrix least squares to a finalR value of 0.045 with 3032 unique reflections. The dihedral angle between the substituents phenyl ring B and the phenyl A is 94.7(3)°. The S atom is in the usual distorted tetrahedral configuration.     

Synthesis of liquid crystals based on hydrogen-bonding of 4-(Octyloxy)benzoic acid with 4-alkylbenzoic acids

A molecular recognition process has been used to form new mesogenic molecular structures, where intermolecular hydrogen bonding occurs between 4-(octyloxy)benzoic acid (8BAO) and four 4-alkylbenzoic acids (nBAs, n = 2, 5, 6, 7). The synthesis of these complexes has been attained by resorting to mechanochemistry. The resulting materials have been characterized by polarizing optical thermal microscopy, differential scanning calorimetry, vibrational spectroscopy, X-ray powder diffraction, and ¹H NMR relaxometry. All the elements of the series show the formation of a mesophase. For one of the complexes, its electro-optical properties have also been assessed, resulting comparable to those of other widely used liquid crystals.     

Solid-phase synthesis and crystal structure of 5(3-nitrophenyl)-3,7-diphenyl-4H,6H-1,2-diazepine

The title compound, 5-(3-nitrophenyl)-3,7-diphenyl-4H,6H-1,2-diazepine (C₂₃H₁₉N₃O₂), was synthesized, in 76% yield, by one-pot multicomponent solid-phase reaction of 3-nitrobenzylidene phenyl ketone, acetophenone and hydrazine, using the catalyst bismuth nitrate, co-catalyst ZnCl₂, adsorbed on neutral alumina, at 110°C. The compound was characterized by spectral methods and X-ray diffraction studies. The crystals are monoclinic, space group P2₁/c: a = 12.186(2), b = 14.769(3), c = 11.046(2) Å, β = 115.023(3)°, Z = 4; R = 0.0418 for 2576 observed reflections. The diazepine ring assumes a twist chair conformation. The dihedral angles between the mean planes through the diazepine ring and the nitrophenyl rings and two phenyl are: 89.19(5)°, 45.85(5)° and 20.80(6)°, respectively. The crystal structure is stabilized by C-H…N, C-H…O, C-H…π hydrogen bonds and π-π-stacking interactions.