scholarly journals A Novel ZnII Complex Bearing Two Monodentate (4-Methoxyphenyl)[(1E, 2E)-3-phenylprop-2-en-1-ilidene] Schiff Bases: Crystal Structure and DFT Study

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Giuliano M. Cordeiro ◽  
Emanoel Hottes ◽  
Andressa Esteves-Souza ◽  
Guilherme P. Guedes ◽  
Carlos Maurício R. de Sant’Anna ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Structural Features ◽  
Chloride Ions ◽  
Basis Set ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hybrid Functional ◽  
Schiff Base Ligands ◽  
Tetrahedral Geometry ◽  
H Nmr

A novel ZnII complex bearing two monodentate (4-methoxyphenyl)[(1E, 2E)-3-phenylprop-2-en-1-ilidene] Schiff bases was synthesized and investigated both in the solid state by single-crystal X-ray diffraction, elemental analysis, and FTIR and in solution by 1H NMR spectroscopy. The complex crystallizes in the P21/c monoclinic space group. The asymmetric unit contains one ZnII ion coordinated to two Schiff base ligands and two chloride ions, in a distorted tetrahedral geometry. The title complex was also investigated by DFT, using the hybrid functional B3LYP with basis set 6-31G++, which reproduced the geometry and structural features of the complex in the crystal, and was used to assign the main bands in the FTIR spectrum. In solution, the complex maintains its integrity against decomposition to the parent reagents.

Synthesis and Structure of a Palladium(II) Chloride Complex with 2-(2-Methyl-3-phenyl-isoxazolidin-5-yl)-pyridine

2000 ◽  
Vol 55 (5) ◽  
pp. 373-376 ◽  
Author(s):  
Andrey B. Lysenko ◽  
Oleg V. Shishkin ◽  
Rostislav D. Lampeka
Keyword(s):  
Chelate Ring ◽  
Organic Ligand ◽  
Chloride Complex ◽  
Monoclinic Space Group ◽  
Equatorial Orientation ◽  
X Ray Diffraction ◽  
Methyl Group ◽  
X Ray ◽  
H Nmr ◽  
Square Planar

The 1:1 complex of palladium(II) chloride with 2-(2-methyl-3-phenyl-isoxazolidin-5-yl)- pyridine (L) has been prepared and studied by means of elemental analysis, 1H NMR spectroscopy and X-ray diffraction (monoclinic, space group P21/n with parameters: a = 8.141(2), b = 9.750(2),c = 20.691(6)Å ,β = 95.62(3)°,V = 1634.4(7)Å3 ,Z = 4 ;R1= 0.054 and wR2= 0.144 for 3352 unique reflections). A square-planar coordination polyhedron has been established for the palladium atom both in acetone solution and in the solid state. The organic ligand is coordinated toometal in a bidentate manner via nitrogen atoms of the pyridine substituent (Pd-N(2) 2.125(3) Å) and the isoxazolidine heterocycle (Pd-N(l) 2.102(3) Å). The other two coordination positions of palladium are occupied by chlorine atoms (Pd-Cl(l) 2.321(1) and Pd-Cl(2) 2.333(1) Å). The six-membered chelate ring formed by Pd, N(2), C(4), C(1), 0(1) and N (1) possesses a “twist-tub” conformation. The isoxazolidine cycle has an envelope conformation with an equatorial orientation of the methyl group.

scholarly journals Synthesis and Molecular Structure of 4′,9′,4″,9″-Tetra-tert-butyl-1′,6′,1″,6″-tetramethoxy-2,5-dioxa[3.3]metabiphenylophane

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Tetsuji Moriguchi ◽  
Tatsuya Egami ◽  
Akihiko Tsuge
Keyword(s):  
Molecular Structure ◽  
Condensation Reaction ◽  
Solvent Molecule ◽  
Dihedral Angles ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
H Nmr ◽  
Crystal Space

A large calixarene-like metacyclophane, 4′,9′,4″,9″-tetra-tert-butyl-1′,6′,1″,6″-tetramethoxy-2,5-dioxa[3.3]metabiphenylophane, was synthesized by an intermolecular condensation reaction of its corresponding bischloromethyl-biphenyl and bishydroxymethyl-biphenyl precursors. After molecular characterization by 1H NMR spectroscopy and mass spectrometry, the compound generated single crystals by recrystallization from a dichloromethane/hexane mixture, facilitating an exact conformational determination via X-ray diffraction analysis. The crystal was found to belong to the monoclinic space group P21/n with cell parameters a = 19.908(2) Å, b = 9.7193(11) Å, c = 23.350(3) Å, β = 109.594(1)°, and Dcalc=1.150 g/cm3 at 90 K. The compound adopted quite strained 1,2-alternate-like conformations because its biphenyl parts displayed large dihedral angles and rigidity. The crystal did not incorporate any solvent molecule but its molecular cavity and crystal space were effectively filled by the substituents.

Experimental and theoretical studies of the products of addition–elimination reactions between benzil dihydrazone and three isomeric chlorobenzaldehydes

2015 ◽  
Vol 71 (7) ◽  
pp. 554-563 ◽  
Author(s):  
Yun-Na Liu ◽  
Shuang-Shuang Cheng ◽  
Chao Wang ◽  
Dian-Xiang Xing ◽  
Yun Liu ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Density Functional ◽  
Double Helix ◽  
Structural Features ◽  
Supramolecular Interactions ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Double Helix Structure ◽  
Homo Lumo

A series of mono- and di-Schiff bases formed between benzil dihydrazone {BDH; systematic name: (1Z)-[(2E)-2-hydrazinylidene-1,2-diphenylethylidene]hydrazine} and three isomeric chlorobenzaldehydes were designed and synthesized to be used as model compounds to help to explain the reaction mechanisms for the formation of Schiff bases. These compounds are 1-(2-chlorobenzylidene)-2-{2-[2-(2-chlorobenzylidene)hydrazin-1-ylidene]-1,2-diphenylethylidene}hydrazine (BDHOCB), and the 3-chloro (BDHMCB) and 4-chloro (BDHPCB) analogues, all having the formula C28H20Cl2N4. Surprisingly, only di-Schiff bases were obtained; our attempts to push the reaction in favour of the mono-Schiff bases all failed. Density functional theory (DFT) calculations were performed to explain the trend in the experimental results. In the case of the systems studied, the type of Schiff base produced exhibits a clear dependence on the HOMO–LUMO energy gaps (ΔEHOMO–LUMO),i.e.the product is mainly governed by its stability. The compounds were characterized by single-crystal X-ray diffractometry, elemental analysis, melting point,1H NMR and13C NMR spectroscopy. The structural features of the three new Schiff bases are similar. For instance, they have the same chemical formula, all the molecules have a symmetrical double helix structure, with each Ph—C=N—N=C—Ph arm exhibiting ananticonformation, and their supramolecular interactions include intermolecular π–π and weak C—H...π stacking interactions. The crystal systems are different, however,viz.triclinic (space groupP\overline{1}) for BDHPCB, monoclinic (space groupP21/n) for BDHOCB and orthorhombic (space groupPnna) for BDHMCB.

Preparation and characterization of azaindolyl-azaindole and structure of its halogen-free dicationic cluster containing the µ4-oxotetracopper(II) core

1994 ◽  
Vol 72 (11) ◽  
pp. 2339-2347 ◽  
Author(s):  
Jacques Poitras ◽  
André L. Beauchamp
Keyword(s):  
Chloride Ions ◽  
X Ray Diffraction ◽  
Solid Mixture ◽  
H Nmr ◽  
Disordered Lattice ◽  
Square Planar ◽  
Nitrogen Donor ◽  
Dark Green ◽  
Halogen Free

Refluxing NbCl5 and excess 7-azaindole (Haza) in benzene yielded a solid mixture containing NbCl5(Haza), NbCl4(Haza)2, the azaindolium ion (H2aza)+, and the azaindolyl-azaindolium ion (H2aza-aza)+. The neutral (Haza-aza) molecule was obtained from the hydrolysed mixture and shown by X-ray diffraction (monoclinic, P21/c, a = 10.025, b = 13.758, c = 8.416 Å, β = 102.89°, Z = 4, R = 0.035) to result from the coupling of two azaindole units via N7—C6′. This compound was the only oxidation product detected, but concurrent formation of other niobium- and (or) azaindole-containing products keeps the yield of Haza-aza low. Dark green crystals of [Cu4O(aza-aza)4]Cl2•6.5H2O were obtained from (Haza-aza) and CuCl2 in wet methanol. The crystal structure (monoclinic, C2/c, a = 17.704, b = 25.240, c = 14.457 Å, β = 116.14°, Z = 4, R = 0.051) shows the presence of a tetranuclear dicationic cluster consisting of a µ4-oxide ion surrounded by a tetrahedron of Cu(II) atoms. A distorted square-planar coordination is achieved about each copper atom by (aza-aza)− ligands each bridging two copper atoms and providing a third nitrogen donor to one of them. For each such cation, the unit cell also includes two chloride ions and 6.5 disordered lattice water molecules. The 1H NMR and infrared spectroscopy data are discussed.

scholarly journals A New 3D Coordination Polymer of Bismuth with Nicotinic AcidN-Oxide

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Farzin Marandi ◽  
Ingo Pantenburg ◽  
Gerd Meyer
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Coordination Polymer ◽  
Three Dimensional ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Thermal Stability Of

The new three-dimensional coordination polymer {[Bi(NNO)2(NO3)]·1.5H2O}n(1, NNO−= nicotinateN-oxide) was synthesized and characterized by elemental analysis, IR and1H-NMR spectroscopy, as well as single-crystal X-ray diffraction analysis.1crystallizes in the monoclinic space group C2/c. The crystal structure consists of a rectangular-shaped grid constructed with NNO linkers. Cavities of a diameter of 7.9–8.3 Å2are filled with disordered water molecules. The thermal stability of the compound was evaluated by thermogravimetric analysis.

scholarly journals Theoretical and X-ray diffraction studies of organic photovoltaic compounds

2014 ◽  
Vol 70 (a1) ◽  
pp. C996-C996
Author(s):  
Abdelkader Chouaih ◽  
Salem Yahiaoui ◽  
Nadia Benhalima ◽  
Manel Boulakoud ◽  
Rachida Rahmani ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Organic Semiconductor ◽  
Density Functional ◽  
Energy Gap ◽  
Three Dimensional ◽  
Basis Set ◽  
X Ray Diffraction ◽  
Hybrid Functional ◽  
X Ray ◽  
Lowest Unoccupied Molecular Orbital

The electronic and structural properties of thiazolic ring derivatives were studied using density functional theory (DFT) and X-ray diffraction in terms of their application as organic semiconductor materials in photovoltaic devices. The B3LYP hybrid functional in combination with Pople type 6-31G(d) basis set with a polarization function was used in order to determine the optimized geometries and the electronic properties of the ground state, while transition energies and excited state properties were obtained from DFT with B3LYP/6-31G(d) calculation. The investigation of thiazolic derivatives formed by the arrangement of several monomeric units revealed that three-dimensional (3D) conjugated architectures present the best geometric and electronic characteristics for use as an organic semiconductor material. The highest occupied molecular orbital (HOMO) . lowest unoccupied molecular orbital (LUMO) energy gap was decreased in 3D structures that extend the absorption spectrum toward longer wavelengths, revealing a feasible intramolecular charge transfer process in these systems. All calculations in this work were performed using the Gaussian 03 W software package.

Synthesis and Crystal Structure of (1E,2E)-1,2-Di (-3-Nitrobenzylidene) Hydrazine under Micromave Irradiation

2013 ◽  
Vol 787 ◽  
pp. 205-207
Author(s):  
Hong Yan Zhou
Keyword(s):  
Crystal Structure ◽  
Microwave Irradiation ◽  
Monoclinic Space Group ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
H Nmr ◽  
The Stability ◽  
High Yields

A compound of (1E,2E)-1,2-di (-3-nitrobenzylidene) hydrazine was synthesized under microwave irradiation (500 w), giving high yields of products (93%). Its structure was determined IR, 1H NMR, MS, elemental analysis and X-ray diffraction. The crystal of the compound is Monoclinic, space group P2(1)/n with a = 6.9611(18), b = 7.823(2), c = 12.999(3) Å, α = 90, β = 105.215(4), γ = 90o, V= 683.1(3) Å3, Z=4, Dc=1.450g/cm3,μ=0.110 mm-1, F(000)=308, R=0.0401 and wR = 0.1131 for 1273 observed reflection with I>2σ (I). π-π stacking interactions contribute to the stability of the structure.

Narrowing of the 35Cl NQR Lines of Trichloroacetamide Caused by Its Ferroelectric Phase Transition

1990 ◽  
Vol 45 (3-4) ◽  
pp. 327-333 ◽  
Author(s):  
Masao Hashimoto ◽  
Akiko Shono ◽  
Yoshiyuki Mido ◽  
Haruo Niki ◽  
Hiroshi Hentona ◽  
...  
Keyword(s):  
Phase Transition ◽  
Dielectric Behavior ◽  
High Temperature Phase ◽  
Monoclinic Space Group ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
X Ray ◽  
H Nmr ◽  
35Cl Nqr

Abstract Dielectric measurements on single crystals and DSC of the title compound (monoclinic, space group P21) revealed a ferroelectric transition at ca. 355 K (ΔH ≈ 0.5 kJ mol-1) Powder x-ray diffraction indicated that the high temperature phase is also monoclinic and the change in volume at the transition is very small. A displacement of hydrogen atoms is considered as responsible for the appearance of ferroelectricity. The 35Cl NQR signals at ca. 77 K were considerably broad, but a drastic narrowing took place after the compound had once experienced the phase transition. A tentative assignment of the NQR spectrum was made from a calculation of the NQR frequencies based on the CNDO/2 method. Another phase transition was evidenced by a small drift of the DSC curve and a slight anomaly of the dielectric behavior around 358 K. The present 1H NMR experiments gave no indication of the onset of torsional motion of the NH2 group reported to occur at ca. 210 K.

Synthesis and Crystal Structure of 9,9-Dipropionitrilefluorene

2013 ◽  
Vol 787 ◽  
pp. 208-210 ◽  
Author(s):  
Yuan Fang Hu
Keyword(s):  
Addition Reaction ◽  
High Yield ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
H Nmr ◽  
Fused Ring ◽  
Nucleophilic Addition Reaction ◽  
Fused Ring System

A compound of 9,9-dipropionitrilefluorene (C19H16N2,Mr=272.34) was synthesized via nucleophilic addition reaction under microwave irradiation (500 w) within short reaction time (8 min), giving high yield of product (87%). Its structure was determined IR,1H NMR, MS, elemental analysis and X-ray diffraction. The crystal belongs to monoclinic, space group P2(1)/c witha= 21.8358(16),b= 8.9457(7),c= 15.9895(12) Å, β = 105.078(2)o, V= 3015.8(4) Å3,Z=8,Dc= 1.200 g/cm3,μ=0.071 mm-1,F(000)=1152,R=0.0629 andwR= 0.0881 for 3155 observed reflection with I>2σ (I). X-ray analysis reveals that the three fused rings of the fluorene system are almost coplanar and the two propionitrile groups are completely perpendicular to the fused-ring system, the molecular is symmetrical.

A two-dimensional copper(I) polymer containing both molecular rod and anionic bridges: synthesis and crystal structure of (µ-chloro)-(µ-pyrazine)copper(I)

1995 ◽  
Vol 73 (10) ◽  
pp. 1591-1595 ◽  
Author(s):  
J.M. Moreno ◽  
J. Suarez-Varela ◽  
E. Colacio ◽  
J.C. Avila-Rosón ◽  
M.A. Hidalgo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Heavy Atom ◽  
Electronic Spectroscopy ◽  
Chloride Ions ◽  
Monoclinic Space Group ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
Tetrahedral Environment ◽  
Heavy Atom Method

The crystal structure of bright-red crystals of the bidimensional polynuclear diamagnetic (µ-chloro)(µ-pyrazine)copper(I) complex has been analyzed from X-ray diffraction data. The structure was solved by the heavy-atom method. Full-matrix least-squares refinement based on 673 reflections with F > 4σ(F) converged to a final R = 0.043 and Rw = 0.048. Crystals of this complex are monoclinic, space group P2/c, a = 3.814(1), b = 6.356(1) and c = 11.497(5) Å; β = 96.04(2)°, Z = 2. The structure consists of planes of copper(I) atoms linked by pyrazine and Cl− bridges, each Cu(I) being in a distorted tetrahedral environment formed by two chloride ions and two nitrogen atoms belonging to two pyrazine molecules, with bond distances of Cu—Cl = 2.349(1) and Cu—N = 2.038(4) Å. Vibrational and electronic spectroscopy of the title compound is also reported. Keywords: two-dimensional copper(I)–pyrazine complexes.

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