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 Crystal Structure of a Four-coordinated Cobalt Complex with 1-Methylbenzimidazole

A four-coordinated complex, L₂Co(NCO)₂, (L = 1-methylbenzimidazole) has been synthesized and characterized by IR spectroscopy, elemental analyses, and single crystal X-ray diffraction. The crystal is monoclinic, a = 14.522(2) Å, b = 14.610(2) Å, c = 8.6850(13) Å, β = 92.037(3)°, Z = 4, sp. gr. P2₁/c. Bond lengths Co–N(L) are equal to 2.0165(16) and 2.0174(15) Å, Co–O(NCO) are 1.944(2) and 1.945(2) Å. Intermolecular C–H···O, C–H···N, and C–H···π interactions link the molecules into three-dimensional networks in the crystal.     

Crystal structure of 2-(thiophen-2-yl)-1-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)ethenyl]benzamide : <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylformamide (1 : 1)

The title compound, 2-(thiophen-2-yl)-1-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)ethenyl] benzamide:N,N-dimethylformamide (1: 1), (C₁₅H₁₁N₃O₂S₂ · C₃H₇NO), was synthesized, and its structure was established by spectral analysis and X-ray diffraction studies. The compound crystallizes in the monoclinic space group P2₁/n with a = 10.8714(7), b = 9.0497(5), c = 19.8347(13) Å, β = 91.093(5)°, Z = 4. The crystal structure is stabilized by N–H···S, C–H···O and N–H···O hydrogen bonds. The π···π interactions are also observed between the rings.     

Structure of (2<Emphasis Type="Italic">E</Emphasis>)-Ethyl 2-((4-(cyanomethoxy)benzylidene)hydrazono)-3,4-dimethyl-2,3-dihydrothiazole-5-carboxylate Studied by X-ray and DFT Calculations

The molecular structure of (2E)-ethyl 2-((4-(cyanomethoxy)benzylidene)hydrazono)-3,4-dimethyl-2,3-dihydrothiazole-5-carboxylate was determined using X-ray diffraction. The crystals are triclinic: sp. gr. P1; Z = 2; the unit cell parameters a = 8.4747(7) Å, b = 8.9382(8) Å, c = 11.9913(10) Å. The title compound has two C–H···O type intramolecular hydrogen bonds, one C–H···O and one C–H···N type intermolecular hydrogen bonds. For theoretical calculations, the molecular structure was investigated by DFT/B3LYP method with 6-311G(d) and 6-311G(d, p) basis sets. The calculated and experumental results (bond lenghts, bond angles, and dihedral angles) were compared with each other. Total energy, dipole moment, and mulliken atomic charges were calculated using two different basis sets.     

Crystal Structure of 4-Amino-3-(thiophen-2-ylmethyl)-1H-1,2,4-triazole-5(4H)one Monohydrate

The molecular structure of the 4-amino-3-(thiophen-2-ylmethyl)-1H-1,2,4-triazole-5(4H)one monohydrate was determined by X-ray diffraction. The compound crystallizes in the monoclinic sp. gr. C2/c with Z = 4 in the unit cell. The title compound is not planar. The dihedral angle between the thiophene and 1,2,4-triazole rings is 73.4(5)°. In the crystal structure, the molecules are connected by intermolecular N–H···O, N–H···N, O–H···O, and C–H···N type hydrogen bonds. The N–H···N and C–H···N hydrogen bonds link the molecules into infinite chains along the c axis.     

Synthesis,Spectroscopic and Crystal Structure Analysis of <Emphasis Type="Italic">N</Emphasis>-[imidazolidin-2-ylidene]-5-(thien-2-yl)[1,3,4]thiadiazole-2-amine

The crystal structure of the title compound has been determined. The compound crystallizes in the monoclinic space group P2₁/c with a = 5.9885(2) Å, b = 14.7345(4) Å, c = 12.3719(4) Å, β = 96.655(5)°, V = 1084.31(8) Å³, z = 4. An intramolecular N–H···N hydrogen bond forms a pseudo-six-membered ring with graph set S ¹ ₁(6). The crystal structure is stabilized by intermolecular interactions of the type N–H···N and C–H···N. The packing motifs in accordance with Etter’s analysis are R ² ₂(8) corresponding to N–H···N dimer and that generated by the chain is C(7).     

Synthesis,characterization, and crystal structure of 5,5″-Difluoro-1<Emphasis Type="Italic">H</Emphasis>,1″<Emphasis Type="Italic">H</Emphasis>-[3,3′:3′,3″-terindol]-2′(1′<Emphasis Type="Italic">H</Emphasis>)-one

The new indole derivative, 5,5′′-Difluoro-1H,1′′H-[3,3′:3′,3′′-terindol]-2′(1′H)-one C₂₄H₁₅F₂N₃O, is synthesized in 87% yield, and its crystal structure is determined by X-ray structure analysis. The crystals are monoclinic, sp. gr. P2₁/n, a = 15.4563(7), b = 10.8340(6), c = 16.4718(6) Å, β = 102.403(4)°, Z = 4. Bicyclic indole moieties form dihedral angle of 61.92(5)° with each other; the oxindole ring is twisted with respect to them at angles of 85.70(5)° and 75.62(5)°. The crystal structure is stabilized by N–H···O and C–H···O hydrogen bonds involving both the DMSO solvent molecules. In addition, one C–H···π interaction is observed.     

Synthesis,antityrosinase activity of curcumin analogues,and crystal structure of (1<Emphasis Type="Italic">E</Emphasis>,4<Emphasis Type="Italic">E</Emphasis>)-1,5-bis(4-ethoxyphenyl)penta-1,4-dien-3-one

Five derivatives of curcumin analogue (R = OCH₂CH₃ (1), R = N(CH₃)₂ (2), R = 2,4,5-OCH₃ (3), R = 2,4,6-OCH₃ (4), and R = 3,4,5-OCH₃ (5)) were synthesized and characterized by ¹H NMR, FT-IR and UV–Vis spectroscopy. The synthesized derivatives were screened for antityrosinase activity, and found that 4 and 5 possess such activity. The crystal structure of 1 was determined by single crystal X-ray diffraction: monoclinic, sp. gr. P2₁/c, a = 17.5728(15) Å, b = 5.9121(5) Å, c = 19.8269(13) Å, β = 121.155(5)°, Z = 4. The molecule 1 is twisted with the dihedral angle between two phenyl rings being 15.68(10)°. In the crystal packing, the molecules 1 are linked into chains by C?H···π interactions and further stacked by π···π interactions with the centroid–centroid distance of 3.9311(13) Å.     

Molecular and Crystal Structure of 2-{(<Emphasis Type="Italic">E</Emphasis>)-[(5-Chloro-2-methoxyphenyl)imino]methyl}-4-nitrophenol

The molecular structure of the title compound, C₁₄H₁₁ClN₂O₄, was determined by single crystal X-ray diffraction. The compound crystallizes in the monoclinic sp. gr. P2₁/c with Z = 4. The title compound, C₁₄H₁₁ClN₂O₄, is a Schiff base which adopts the phenol-imine tautomeric form in the solid state.The molecule is almost planar and the dihedral angle between the planes of two aromatic ring is 2.2(1)°. The molecular structure is stabilized by intramolecular O–H···N hydrogen bond which generates a six-membered ring. In the crystal structure, the molecules are linked together by intermolecular C–H···O interactions.     

Crystal and molecular structure of 2-[(4-nitrophenyl)carbonyl]cyclohex-1-ene-1-yl 4-nitrobenzoate

The crystal structure of 2-[(4-nitrophenyl)carbonyl]cyclohex-1-ene-1-yl 4-nitrobenzoate is studied (T = 173 K, R1 = 0.0354 for 2713 observed reflections). This crystal is orthorhombic, a = 7.8367(8) Å, b = 9.6082(10) Å, c = 23.856(3) Å, V = 1796.3(3) ų, space group P2₁2₁2₁, and Z = 4. The molecule has a folded configuration, which is stabilized by π-π interactions between its two parts. A system of intermolecular C-H...O hydrogen bonds (H...O, 2.44–2.67 Å; CHO angles 122°–169°) and intramolecular C-H...O contacts closing five-membered cycles (H...O, 2.42–2.59 Å; CHO angles 96°–102°) are formed in the structure.     

Synthesis,Characterization, Crystal Structure,and Hirshfeld Surface Analysis of Ethyl 2-(4-bromophenyl)-1-cyclohexyl-1<Emphasis Type="Italic">H</Emphasis>-benzo[<Emphasis Type="Italic">d</Emphasis>]imidazole-5-carboxylate

The title compound, C₂₂H₂₃N₂BrO₂ was synthesized via one-pot reductive cyclization method and characterized by CNH analysis, FT-IR, UV-visible, mass, ¹H and ¹³C NMR spectra, thermogravimetric analysis (TGA) and single crystal X-ray diffraction method. The compound crystallizes in monoclinic crystal system: sp. gr. P2₁/c, Z = 4. The crystal data reveals that the intermolecular interactions of the C–H···π and π···π type connect the molecules which was also visualized with the help of Hirshfeld surface analysis.     

3-[4-Bromo-α(<Emphasis Type="Italic">R</Emphasis>*)-methoxybenzyl]-6-chloro-3(<Emphasis Type="Italic">S</Emphasis>*),4(<Emphasis Type="Italic">S</Emphasis>*)-dihydroxychroman: X-ray and DFT Studies

Sodium borohydride reduction of E-3-benzylidenechromanone epoxides in dry methanol has afforded 3(S*), 4(S*)-dihydroxy-3-[α(R*)-methoxybenzyl]chromans as an interesting class of products, the structures of which have been assigned mainly from spectral data and consideration of the mechanistic aspects. X-ray diffraction study of one of them, 3-[4-bromo-α(R*)-methoxybenzyl]-6-chloro-3(S*),4(S*)- dihydroxychroman, is performed. The title compound crystallizes in the monoclinic sp. gr. P2₁/n, with a = 13.336(6) Å, b = 10.866(5) Å, c = 27.166(11) Å, β = 95.193(6)°, V = 3920(3) ų, and Z = 8. Supramolecular construction of the compound involves O–H···O intermolecular hydrogen bonds as well as three other types of non-covalent interactions which are responsible for crystal packing. Density functional theory was applied for geometry optimization, molecular orbital calculations, and prediction of UV spectral features. The geometric parameters (bond lengths, bond angles, and dihedral angles) for the representative compound obtained from density functional theory with B3LY6-31G basis set were in good agreement with experimental values.     

Crystal and Molecular Structure of 3,5-Diphenyl-4,5-dihydro-2-phenylcarboxamide-1H-pyrazole

Crystal structure of the title compound C₂₂H₁₉N₃O is determined by single crystal X-ray diffraction (sp. gr. P2₁/c, Z = 4). The molecule as a whole, is not planar: phenyl cycles are rotated relative to the plane of pyrazole ring. N?H···N intramolecular hydrogen bond forms five-membered ring fused to pyrazole ring. There are also intramolecular C?H···O and C?H···π interactions. Intermolecular C?H···O hydrogen bond links the molecules into a C(7) chain along the a axis. The crystal structure is stabilized also by C–H···π and π···π intermolecular hydrogen bonds.     

Synthesis,structural characterization,and DFT calculations of 3-buthyl-4-(3-methyl-3-mesitylcyclobut-1-yl)-1,3-thiazole-2(3<Emphasis Type="Italic">H</Emphasis>)-thione

The title compound, C₂₁H₂₉NS₂, has been synthesized and its crystal structure has been determined from single crystal X-ray diffraction data. Crystals are monoclinic, a = 11.4923(8), b = 13.1842(7), c = 14.6583(8) Å, β = 109.983(6)°, sp. gr. P2₁/c, Z = 4. Mesityl and thiazole groups are in cis positions with respect to the cyclobutane ring. The cyclobutane ring is puckered, with a dihedral angle of 26.6(2)° between the two three-atom planes. The crystal structure involves one weak intermolecular C–H···S hydrogen-bond. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311G(d, p) basis set in ground state. Geometric parameters (bond lengths, bond angles and torsion angles) and vibrational assignments have been calculated theoretically and compared with the experimental data.     

Crystal Structure of Two <Emphasis Type="Italic">V</Emphasis>-shaped Ligands with <Emphasis Type="Italic">N</Emphasis>-Heterocycles

Two V-shaped ligands with N-heterocycles, bis(4-(1H-imidazol-1-yl) phenyl)methanone (1), and bis(4-(1H-benzo[d]imidazol-1-yl)phenyl)methanone (2) have been synthesized and characterized by elemental analyses, IR and 1H NMR spectroscopy. Crystal structures of 1 and 2 have been determined by X-ray diffraction. The crystal of 1 is monoclinic, sp. gr. P2₁/c, Z = 4. The crystal of 2 is orthorhombic, sp. gr. Fdd2, Z = 8. X-ray diffraction analyses show that the V-shaped angles of 1 and 2 are 122.72(15)° and 120.7(4)°, respectively. Intermolecular C–H···O, C–H···N, C–H···π, and π···π interactions link the components into three-dimensional networks in the crystal structures.     

Crystal structure of (<Emphasis Type="Italic">E</Emphasis>)-3-fluoro-N-((5-nitrothiophen-2-yl)methylene)aniline

The structure of the title compound C₁₁H₇FN₂O₂S was characterized by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2₁/n with Z = 12, i.e. with three molecules in asymmetric unit. The molecules are not planar: the dihedral angles between the planes of thiophene and the benzene rings are 42.3(3)°, 42.0(3)°, and 48.9(2)°. In the crystal, intermolecular C–H···F interactions link the molecules through R₂² (14) ring motif. The crystal packing is also stabilized by π···π interactions.     

Crystal structure of (2<Emphasis Type="Italic">Z</Emphasis>)-(3,3-dimethyl-3,4-dihydroisoquinolin- 1(2<Emphasis Type="Italic">H</Emphasis>)-ylidene)nitrosoacetonitrile

The crystal structure of (2Z)-(3,3-dimethyl-3,4-dihydroisoquinolin-1(2Н)-ylidene)nitrosoacetonitrile is determined (T = 150 K, R1 = 0.0435). The compound crystallizes as the E-cis and Z-cis isomers of the nitroso tautomer. Two independent molecules differ in the rotation of the nitroso group about the С–С bond between the dihydroisoquinoline group and the substituent. Analysis of bond lengths reveals their conjugation and prevailing contribution of the zwitter-ionic structures with the positive charge located on the isoquinoline fragment and the negative charge located on the substituent. Molecules having E and Z conformations are connected by the N–H···O hydrogen bond (N···O 2.922(3) Å) into dimers. The N–H group of the other molecule forms the intramolecular N–H···O hydrogen bond (N···O 2.544(3) Å) which closes a sixmembered cycle. Electronic absorption spectra are studied, and quantum-chemical modeling of the compound is performed.     

Synthesis and Crystal Structures of Ethyl 2-(4-Methoxyphenyl)-1<Emphasis Type="Italic">H</Emphasis>-benzo[<Emphasis Type="Italic">d</Emphasis>]imidazole-5-carboxylate Dihydrate and Its Building Block 4-Fluoro-3-nitrobenzoic Acid

The title compound, ethyl 2-(4-methoxyphenyl)-1H-benzo[d]imidazole-5-carboxylate dihydrate (5), was synthesized and its crystal structure was studied by single-crystal X-ray diffraction technique. Compound 5 is crystallized in the centrosymmetric triclinic space group \(P\bar {1}\) with Z?=?4 and Z′?=?2, and unit-cell parameters of a?=?8.9190 (3) Å, b?=?12.6888 (4) Å, c?=?14.7111 (5) Å, α?=?98.4855 (10)°, β?=?101.6379 (9)°, γ?=?95.4346 (10)° and V?=?1599.43 (9) ų. Its starting material, 4-fluoro-3-nitrobenzoic acid (1), is crystallized in the non-centrosymmetric monoclinic space group P2₁ and Z?=?4 with unit-cell parameters of a?=?3.7170 (4) Å, b?=?12.6475 (13) Å, c?=?15.5237 (15) Å, α?=?90°, β?=?91.9786 (16)°, γ?=?90° and V?=?729.35 (13) ų. It was noted that strong hydrogen bonds play important roles in the crystal packing of both compounds, especially in 5, in which the co-crystallized water molecules act as both strong hydrogen bond donor and strong hydrogen bond acceptor.

Graphical Abstract

Two molecule of compound 5 crystallized in a non symmetrical manner with four co-crystallized water molecules which play an important role in the crystal packing as strong hydrogen-bond donors.

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X-ray and Theoretical Studies of 2-((5-Amino-1,3,4-thiadiazol-2-yl)thio)-1-phenylethanone

The crystal structure of 2-((5-amino-1,3,4-thiadiazol-2-yl)thio)-1-phenylethanone was determined by X-ray diffraction method. The compound crystallizes in orthorhombic crystal system, sp. gr. Pbca. The atoms that constitute thiadiazole and phenyl rings do not form any significant deviation from the ring planes. Compound has two intermolecular N–H···N hydrogen bonds and one C–H···π interaction. Using DFT/B3LYP method with 6-31G(d), 6-311G(d), 6-311G(d, p), and 6-311++G(d, p) basis sets, the molecular geometry of the compound was optimised. Bond lenghts, bond angles, torsion angles, dihedral angles, and HOMO–LUMO were calculated from the optimised geometry of the compound. The results obtained by X-ray diffraction method were compared with the results obtained through four different basis sets. Total energy of the molecule was calculated for four different basis sets.     

Synthesis,Crystal Structure,and Free Radical Scavenging Activity of 4-Aminopyridinium 3,5-Dinitrobenzoate

The crystal structure of 4-aminopyridinium 3,5-dinitrobenzoate, C₁₂H₁₀O₆N₄, has been determined by single-crystal X-ray diffraction technique. The title compound crystallizes in the monoclinic sp. gr. P21/n with the unit cell parameters: a = 7.4726(3) Å, b = 23.0898(9) Å, c = 8.0744(4) Å, V = 1338.64(10) ų, Z = 4. The asymmetric unit of the compound consists of one 3,5-dinitrobenzoate anion and 4-aminopyridine cation. The adjacent anions and cations are linked through two N?H···O hydrogen bonds, N2?H2A···O5 and N₂?H2B···O6, to form an infinite chain of anions and cations, extended along the [010] direction.