Synthesis and crystal structure elucidation of 1-(4-fluorobenzyl)-2-(4-cyanophenyl)-1H- benzimidazole-5-carbonitrile

The synthesis and spectral identification of 1-(4-fluorobenzyl)-2-(4-cyanophenyl)-1H-benzimidazole-5-carbonitrile (1) have been reported. IR, ¹H NMR, and EI mass spectral analysis were used for its spectral identification. The structure of 1 was confirmed by X-ray crystallographic studies. Intramolecular hydrogen bond occurs between the imidazole nitrogen and one of hydrogen of the florobenzene. The crystal packing is governed by C–HN intermolecular hydrogen bonds. The molecular structure observed in crystal and the optimised geometries at the HF level by doing semi-empirical and ab initio calculations were compared.     

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.     

Structure of 2-{2-[3-methyl-3-(2,4,6-trimethylphenyl) cyclobutyl]-2-oxoethyl}isoindole-1,3-dione

2-{2-[3-Methyl-3-(2,4,6-trimethylphenyl)cyclobutyl]-2-oxoethyl}isoindole-1,3-dione (C₂₄ H₂₅NO₃) was synthesized, and its crystal structure was determined by X-ray crystallographic techniques. The compound crystallizes in the triclinic space group P-1, with unit cell parameters: a = 14.109(9) Å, b = 14.130(8) Å, c = 12.152(6) Å, = 105.62(5)°, = 113.75(4)°, = 98.78(5)°, V = 2039.8(19) ų, D _c= 1.223 g/cm³, and Z = 4. The crystal structure has two crystallographically independent molecules, I and II. These molecules are held together by weak intermolecular C—H···O interactions, forming a continuous chain. The dihedral angles between the N-substituted phthalimide moiety and cyclobutane ring in molecules I and II are 60.37(14) and 68.18(18)°, respectively.     

Synthesis and structural study of 1-(N,N-diethylamino)-2,2-bis(2-nitrophenylthio)ethene

The synthesis, variable temperature NMR spectra, and crystal structures of two crystalline forms, 2a and 2b, of the enamine 1-(N,N-diethylamino)-2,2-bis(2-nitrophenylthio)ethene have been obtained. Both forms crystallize in the monoclinic space group P2₁/a. The two phases have similar molecular structures but possess different intermolecular C–H······O hydrogen bonding interactions. Both forms exhibit disorder within the NEt₂ fragment at 298 K: sufficient disorder persisted with 2a (orange needles) down to 100 K to make the geometric parameters pertaining to the enamine fragment unreliable. The disorder was effectively eliminated on cooling 2b down (red colored blocks) to 150 K. Cell dimensions for the 2a-phase are at 100 K: a = 11.1030(4) Å, b = 15.1325(7) Å, c = 12.4504(7) Å, β = 114.606(3)°, while for the 2b-phase at 150 K, a = 15.5206(4) Å, b = 7.6958(2) Å, c = 15.7137(3) Å, β = 92.580(7)°. The C–N bond length in the β-form at 150 K of 1.335(3) Å indicates considerable double bond character: the rotational barrier of the C–N bond in CDCl₃ was calculated to be 52.4 kJ mol^?1.     

Synthesis and Crystal Structure of 3-[(Naphthalen-2-yl)methyl]Isocoumarin

Abstract 3-[(Naphthalen-2-yl) methyl]isocoumarin was synthesized by the reaction of homophthalic acid with 2-(naphthalen-2-yl)acetyl chloride at elevated temperature and its crystal structure has been determined (C₂₀H₁₄O₂), Mr = 286.31, a = 13.704(3), b = 7.356(4), c = 7.042(7) ?, β = 99.21(3)°, space group Pc, Z = 2, and V = 700.7(8) ?³. The isocoumarin and the naphthalene ring systems are individually planar and the dihedral angle between the mean planes of these two ring systems is 70.05(8)°. Graphical Abstract Synthesis and crystal structure of 3-[(Naphthalen-2-yl)methyl]isocoumarin Aamer Saeed, Junmei Liang, Masood Parvez The synthesis and crystal structure of a novel isocoumarin, 3-[(naphthalen-2-yl)methyl]isocoumarin has been presented.      

4-(2-Methylphenyl)-1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-dione (I) and 4-(4chlorophenyl)-1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-dione (II)

The crystal and molecular structures of the title compounds have been determined by x-ray structure analysis. The compounds (I) and (II) crystallize in space groups P2₁2₁2₁ and 12/a respectively. The structures were solved by direct methods and refined to R = 0.058 and R = 0.046. The saturated pyrimidine-2-one ring in both structures deviates from the planarity. There are two intermolecular hydrogen bonds in (I) and (II). The configuration at C4 in (I) is S.     

Metal complexes of chiral pyridine ligands. X-ray structure of nitratobis {2-(2S)-2-pyrrolidinyl]pyridine} copper (II) nitrate

Cobalt(II), nickel(II), and copper(II) complexes of 2-[(2S)-2-pyrrolidinyllpyridine (L) have been synthesized and characterized. The crystal structure of the complex [Cu(L)₂(NO₃)]NO₃ has been determined by X-ray diffraction. Crystals are monoclinic, space groupP2+, witha=10.766(3).b=7.525(2),c=13.447(4) Å. =104.64(2)°. and Z=2. The structure consists of [Cu(L)₂(NO₃)]⁺ cations and NO ₃ ^t- anions. The copper atom has a distorted trigonal bipyramidal coordination geometry with the two pyrrolidine nitrogens and one nitrate oxygen occupying the equatorial positions and the two pyridine nitrogens at the apices. The crystalline cohesion is ensured by a network of hydrogen bonds involving the pyrrolidine groups as donors and both coordinate and uncoordinate nitrates as acceptors.     

Low temperature photoluminescence studies on semiorganic tris thiourea copper (I) chloride single crystal

Semiorganic tris thiourea copper (I) chloride (TTCC) single crystals have been synthesized from copper (II) chloride via slow evaporation technique. The stoichiometry of the grown anhydrous complex crystal has been confirmed by elemental CHNS (C, H, N and S) and atomic absorption spectrophotometric (AAS) analysis. The crystal structure with space group has been confirmed by single crystal and powder X‐ray diffraction (XRD) studies. The FTIR study assigned the presence of functional groups and confirmed the co‐ordination of metal ions with thiourea. It also confirmed the transition from Cu²⁺ to Cu⁺ when thiourea combined with Copper (II) chloride. The optical transparency of the crystal has been studied by UV‐Vis spectrum and deduced the energy gap. The room temperature Photoluminescence (PL) spectrum reported maximum emission line at 410.92 nm and Stokes shift has been determined as 75 nm or 16.5 eV. Low temperature luminescence study from 300 K to 77 K exhibited three blue emission peaks and one green emission peak. The green emission band has been assigned to recombination of an electron in a shallow trap and Cu²⁺. Blue emission has been attributed to S^2‐ vacancies. The interesting hysteresis loop has been exhibited by the variation of energy gap with low temperature. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Polymorphic single crystal ↔ single crystal transformations in Rb0.975Cs0.025NO3

The crystal growth morphology of modifications IV, III, II, and I during the IV ↔ III ↔ II ↔ I polymorphic transformations in Rb_0.975Cs_0.025NO₃ has been investigated by optical microscopy. The equilibrium temperatures between phases IV and III (T ₀ = 393 ± 0.5 K), III and II (T ₀ = 421 ± 0.5 K), and II and I (T ₀ = 497 ± 0.5 K) of the crystal studied have been determined. It is established that these transformations are of the single crystal ↔ single crystal type and occur with the formation and growth of new-crystal nuclei in crystalline matrices.     

Synthesis,crystal structure,HF and DFT calculations of 1-(2-chlorobenzyl)-N-(1-(2-chlorobenzyl)-4,5-dihydro-1H-imidazol-2-yl)-1H-benzimidazol-2-amine

The titled compound (1), has been synthesized and characterized by IR and ¹H-NMR spectroscopy, and single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P-1. The crystal structure is stabilized by C-H…π and aromatic π-π interactions. There are also intramolecular N-H…N and C-H…N hydrogen bonds in the molecule. The use of quantum chemical calculations to characterise and optimise the choice of material is illustrated by ab initio treatments. Vibrational frequencies and LUMO-HOMO energy difference of 1 have also been investigated by Density functional theory (DFT) and Hartree-Fock (HF) calculations. Calculated frequencies are in good agreement with the corresponding experimental data.     

Crystal Structure of N-(tert-Butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)cyclohexane Carboxamide

Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been determined. The title compound crystallized in the orthorhombic space group pbca with cell parameters, a = 10.6556(6) ?, b = 18.0132(11) ?, c = 19.5513(12) ?, v = 3752.7(4) ?³, Z = 8, D _cal = 1.269 Mg/m³ at T = 120 K. The structure refined by full-matrix least-squares procedures to find R ₁ = 0.0463 and wR ₂ = 0.0937 for 3059 reflections. The soxazole ring isn’t coplanar with the phenyl ring. Index Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been studied.      

New oxygen-and lead-deficient lead borate Pb 0.9 (I) Pb 0.6 (II) [BO2.25]2 = 2Pb0.75[BO2.25] and its relation to aragonite and calcite structures

Anhydrous oxygen-and lead-deficient lead borate of the composition Pb _0.9 ^(I) Pb _0.6 ^(II) [BO_2.25]₂ = 2Pb_0.75[BO_2.25] (sp. gr. P312) has been obtained by the hydrothermal synthesis. New acentric borate possesses optical nonlinearity comparable with the optical nonlinearity of α-quartz. The crystal structure of new borate is determined and refined by two X-ray diffraction methods—the single crystal diffractometry and the full-profile analysis. All the positions in the structure, except for those of the boron atom in the triangular coordination, are occupied only partly; one of the two lead positions is split. It is established that new borate is closely related to calcium carbonates—aragonite, calcite, and paralstonite. With an increase of the temperature, new borate undergoes the reversible phase transition into the centrosymmetric, most probably, aragonite-like phase.     

Study of optical and transport properties of K2CuCl4 · 2H2O single crystal

Optical absorption, transport properties and EPR of K₂CuCl₄ · 2H₂O single crystals have been studied. The optical absorption in UV, and visible region are characterized by a charge transfer band, and in the near infrared region at 3998, 4336, and 4480 cm⁻¹ are attributed to transitions between the stark levels of copper(II) ion in an extended octahedral crystal field. An anisotrophic ‘g’ value was observed with g_∥ = 2.12 and g_∥ = 2.24 by EPR method. The spin orbit coupling constant is found to be 500 cm₋₁. D.C. electrical conductivity measurements with temperature reveal an anisotropy characteristic of a two-dimensional layered structure and exhibit a first order irreversible structural phase-transition at 377 K, i.e. from tetragonal to monoclinic crystal system. X-ray diffraction studies and density calculations from the crystal structure data in both the phases suggest that the first order irreversible transition occurs following the loss of the two water molecules of hydration.     

2-(4-Phenyl-5-pyridin-2-yl-4H-1,2,4-triazol-3-yl)cyclohexanecarboxylic Acid and Its DMSO Solvate: Synthesis, Crystal Structure and Biological Activity

Abstract  

A new 1,2,4-triazole derivative, 2-(4-phenyl-5-pyridin-2-yl-4H-1,2,4-triazol-3-yl)cyclohexanecarboxylic acid, C₂₀H₂₀N₄O₂ (I), and its dimethyl sulfoxide solvate 1:1 (II) have been synthesized and their crystal structure was established. Compound (I) was screened for its antiproliferative and antiinflammatory activity. Structural analysis indicated the substantial difference between two symmetry independent molecules in (I) and this in (II), it manifests in the relative orientation of pyridine/phenyl and triazole rings, as well as in the orientation of carboxyl group with respect to cyclohexane ring. The molecules A and B in the crystal (I) form two hydrogen-bonded chains through O–H_carboxyl and N_triazole atoms, giving separate catemers of symmetry independent molecules. The catemer of (IA) running along the 2₁ axis is homochiral, while the catemer (IB) is racemic—formed about the c glide plane. In the crystalline solvate (II) complexation of (I) with DMSO induced enantiomeric self-resolution. Obtained crystals are racemic twins, in which each part is built of one enantiomer of (I) having the relative configuration 11S,12R or 11R,12S. A pair of host–guest molecules is linked by the O–H_carboxyl⋯O_DMSO hydrogen bond.     

Thermal and Laser Properties of Nd:YVO4 Crystal

Nd:YVO₄ crystal has been grown by Czochralski method. The data of thermal expansion and specific heat have been measured. The thermal expansion coefficients along a- and c-axis are a₁ = 2.2 x 10^-6 /K, and a₃ = 8.4 x 10^-6 /K respectively. The specific heat is 24.6 cal/mol x K at 330 K. The large anisotropy along c- and a-axis of thermal expansion coefficients is explained by the structure of YVO₄ crystal. 921 mW output laser at 1.06 mikrom has been obtained with a 3 mm x 3 mm x 1mm crystal sample when pumped by 1840 mW cw laser diode, and the slope efficiency is 55.5%.     

Synthesis and crystal structure characterization of (E)-2,2,2-Trifluoro-N-[2-(2-nitrovinyl)phenyl]acetamide

The title compound, (E)-2,2,2-trifluoro-N-[2-(2-nitrovinyl)phenyl]acetamide, was synthesized and characterized by ¹H and ¹³C NMR and HRMS spectroscopy. Its molecular configuration was investigated by X-ray crystallography. The crystal structure analysis revealed that the structure exhibits intermolecular hydrogen bonds of the type N–H…O and intermolecular hydrogen bonds of the type N–H…F, and molecules are linked by weak C–H…O contacts. Furthermore, the two oxygen atoms of nitro group are disordered over two positions, respectively, with site occupancy factors of 0.8:0.2 and 0.6:0.4. Three fluorine atoms are also disordered over two positions, respectively, one fluorine atom with site occupancy factors of 0.6:0.4 and the other two fluorine atoms with site occupancy factors of 0.5:0.5.     

Synthesis and crystal structure of 4-(p-methoxyphenyl)-3, 5-bis(4-pyridyl)-1,2,4-triazole

The 4-(p-methoxyphenyl)-3,5-bis(4-pyridyl)-1,2,4-triazole has been synthesized and its crystal structure has been determined by X-ray diffraction methods. It crystallizes in the monoclinic space group P2₁/n, with a = 12.5832(6) Å, b = 7.0512(5) Å, c = 18.4669(12) Å, = 96.826(1)°, and D_calc = 1.345 g cm^–1 for Z = 4. In the structure, two pyridyl rings, phenyl ring, and triazole ring do not share a common plane. The most favored orientation of the pyridyl rings in the crystal is that their planes are inclined toward opposite directions with respect to the triazole ring.     

Spectroscopic and Transport Properties of (NH4)2CuCl4 · 2 H2O Single Crystal

Electron paramagnetic resonance (EPR), Optical absorption and Transport properties of (NH₄)₂CuCl₄ 2 H₂O single crystals have been studied. An anisotropic g tensor was observed with gl = 2.241 and g∥ = 2.081 by EPR method. The spin orbit coupling constant is found to be 540 cm⁻¹. The optical absorption in UV region are characterized by charge transfer band, in the visible and near infrared region at 13,333, 4,480, 4,336, and 3,998 cm⁻¹ attributed to the transitions between the (d-d) stark energy levels of the copper (II) ion in an extended octahedral crystal field. Dc electrical conductivity measurements with temperature reveal an anisotropic characteristic of a two-dimensional layered structure, and exhibits two first order structural phase transitions at about 383 K and 413 K. These transitions are attributed to loss of the two water inolecules of hydration and free rotation of NH⁺₄ ion from a state of torsional oscillation.     

Crystal and molecular structure of bis(tetramethylammonium) di(π-(1)-2-thiollyl)iron(II)

The crystal and molecular structure of bis(tetramethylammonium)di(-(1)-2-thiollyl)iron(II), C₈H₄₄B₂₀FeN₂S₂, has been determined from three-dimensional X-ray data collected by counter techniques. The material crystallizes in the orthorhombic system: space groupIbam, z=4, a=15·585(5), b=12·324(4), and c=14·806(6) Å. The B₁₀H₁₀S^2– moiety is an icosahedron with the sulphur atom and four boron atoms forming that part of the cage which is within bonding distance of the iron. The sulphur atom and one boron atom are disordered. The structure was solved by standard techniques and the least squares refinement, using 969 independent reflexions for whichF ₀ ² 3(F ₀ ²), converged to a conventionalR factor (onF) of 4·2%.No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission of Plenum Publishing Company Limited.National Lending Library Supplementary Publication No. 60063 contains 2 pages of structure tables on 1 microfiche.     

Crystallographic and Conformational Analysis of [(Z)-2-ethoxy-6-[(2-hydroxyphenylamino)methylene]cyclohexa-2,4-dienone]

Abstract  The single crystal X-ray diffraction analysis of the title compound, C₁₅H₁₅NO₃, shows that the structure is adopted to its NH tautomeric form and crystallizes in the orthorhombic space group P bcn with a = 21.2424(15) ?, b = 12.7696(9) ?, c = 9.3605(10) ?, Z = 8, V = 2539.1(4) ?³, D _c  = 1.346 g/cm³. The molecular conformation in the crystal is stabilized by an intramolecular H-bond and the crystal structure is stabilized by the bifurcated O–H···O type intermolecular H-bonds. In order to understand the effects on conformational flexibility of the title molecule, molecular energy profile was calculated as a function of the selected torsion angle by means of AM1 semi-empirical method. Index Abstract  Molecular and crystal structure of [(Z)-2-ethoxy-6-[(2-hydroxyphenylamino)methylene]cyclohexa-2,4-dienone], C₁₅H₁₅NO₃, have been determined by single crystal X-ray diffraction study, and conformational analysis of the title molecule with respect to the selected torsion angle has been achieved by AM1 semi-empirical calculations.