scholarly journals 2-Hetaryl-1,3-tropolones based on five-membered nitrogen heterocycles: synthesis, structure and properties

2015 ◽  
Vol 11 ◽  
pp. 2179-2188 ◽  
Author(s):  
Yury A Sayapin ◽  
Inna O Tupaeva ◽  
Alexandra A Kolodina ◽  
Eugeny A Gusakov ◽  
Vitaly N Komissarov ◽  
...  
Keyword(s):  
Density Functional ◽  
Acetic Acid Solution ◽  
Intramolecular Proton Transfer ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Dft Methods ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography ◽  
Derivatives Of

A series of derivatives of 2-hetaryl-1,3-tropolone (β-tropolone) was prepared by the acid-catalyzed reaction of 2-methylbenzoxazoles, 2-methylbenzothiazoles and 2,3,3-trimethylindoline with 3,4,5,6-tetrachloro-1,2-benzoquinone. The molecular structures of the three representative compounds were determined by X-ray crystallography. In crystal and (as shown by the DFT PBE0/6-311+G** calculations) in solution, 2-hetaryl-4,5,6,7-tetrachloro- and 2-hetaryl-5,6,7-trichloro-1,3-tropolones exist in the NH-tautomeric form with a strong resonance-assisted intramolecular N–H···O hydrogen bond. The mechanism of the formation of 1,3-tropolones in the reaction of methylene-active five-membered heterocycles with o-chloranil in acetic acid solution has been studied using density functional theory (DFT) methods. The reaction of 2-(2-benzoxa(thia)zolyl)-5,6,7-trichloro(4,5,6,7-tetrachloro)-1,3-tropolones with alcohols leads to the contraction of the seven-membered tropone ring with the formation of 2-(2-benzoxa(thia)zolyl)-6-alkoxycarbonylphenols. The molecular structure of 2-(2-ethoxycarbonyl-6-hydroxy-3,4,5-trichlorophenyl)benzoxazole has been determined by X-ray diffraction. 2-(2-Benzoxa(thia)zolyl)-6-alkoxycarbonylphenols display intense green fluorescence with anomalous Stokes shifts caused by the excited state intramolecular proton transfer (ESIPT) effects.

scholarly journals Synthesis, X-Ray Crystallography, Thermal Analysis, and DFT Studies of Ni(II) Complex with 1-Vinylimidazole Ligand

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fatih Şen ◽  
Ramazan Şahin ◽  
Muharrem Dinçer ◽  
Ömer Andaç ◽  
Murat Taş
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Basis Sets ◽  
Mulliken Charge ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Dft Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Density Functional Theory

The paper presents a combined experimental and computational study of hexa(1-vinylimidazole)Ni(II) perchlorate complex. The complex was prepared in the laboratory and crystallized in the monoclinic space group P21/n with a=8.442(5), b=13.686(8), c=16.041(9) Å, α=γ=90, β=96.638(5), and Z=1. The complex has been characterized structurally (by single-crystal X-Ray diffraction) and its molecular structure in the ground state has been calculated using the density functional theory (DFT) methods with 6-31G(d) and LanL2DZ basis sets. Thermal behaviour and stability of the complex were studied by TGA/DTA analyses. Besides, the nonlinear optical effects (NLO), molecular electrostatic potential (MEP), frontier molecular orbitals (FMO), and the Mulliken charge distribution were investigated theoretically.

Functionalisation of Imidazolin-2-imine to Corresponding Phosphinamine, Chalcogenide (O, S, Se, Te), and Borane Compounds

2015 ◽  
Vol 68 (1) ◽  
pp. 127 ◽  
Author(s):  
Kishor Naktode ◽  
Sayak Das Gupta ◽  
Abhinanda Kundu ◽  
Salil K. Jana ◽  
Hari Pada Nayek ◽  
...  
Keyword(s):  
Good Yield ◽  
Density Functional ◽  
Elemental Sulfur ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Tert Butyl ◽  
Imine Ligands ◽  
Orbital Analysis

1,3-Di-tert-butyl-imidazolin-2-ylidine-1,1-diphenylphosphinamine (2) was prepared from 1,3-di-tert-butyl-imidazolin-2-imine (1) and chlorodiphenylphosphine. Compound 2 was treated further with elemental sulfur, selenium, and tellurium to afford the corresponding chalcogenide derivatives, 1,3-di-tert-butyl-imidazolin-2-ylidine-P,P-diphenyl-phosphinothioicamide (4), 1,3-di-tert-butyl-imidazolin-2-ylidine-P,P-diphenyl-phosphinoselenoicamide (5), and 1,3-di-tert-butyl-imidazolin-2-ylidine-P,P-diphenyl-phosphinotelluroicamide (6) in good yield. 1,3-Di-tert-butyl-imidazolin-2-ylidine-P,P-diphenylphosphinicamide (3) was obtained by dissolving compound 2 in hydrochloric acid solution in THF. The corresponding borane adduct, 1,3-di-tert-butyl-imidazolin-2-ylidine-P,P-diphenyl-phosphinaminoborane (7) was isolated by the reaction of compound 2 and sodium borohydride in good yield. The molecular structures of compounds 2 and 4–7 were established by X-ray diffraction analyses. To analyse the electronic structure of chalcogenides of imidazolin-2-imine ligands, the protonation energies of the oxygen, sulfur, and selenide derivative of ligand 2 were calculated by means of density functional theory. Finally, the charge distribution in compounds 3, 4, and 5 were determined using natural bond orbital analysis.

Comparison of different theory models and basis sets for the calculation of FbC-M10Iso-Bn geometry and geometries of chlorin-imide and chlorin-isoimide isomeric pairs

2013 ◽  
Vol 17 (05) ◽  
pp. 376-383 ◽  
Author(s):  
Jong-Kil Park ◽  
Sang Joon Choe
Keyword(s):  
Density Functional ◽  
Molecular Geometry ◽  
Basis Sets ◽  
Normal Coordinate ◽  
Dft Methods ◽  
Functional Theory ◽  
X Ray ◽  
Bond Lengths ◽  
X Ray Crystallography ◽  
Isomeric Pairs

Various density functional theory (DFT) methods with different basis sets to predict the molecular geometry of FbC-M10Iso-Bn macrocycle, a chlorin-isoimide, are compared in this study. DFT methods, including M06-2X, B3LYP, LSDA, B3PW91, PBEPBE, and BPV86, are examined. Different basis sets, such as 6-31G*, 6-31+G (d, p), 6-311+G (d, p), 6-311++G (d, p), cc-PVDZ, cc-PVTZ, and cc-PVQZ are also considered. The examined hybrid DFT methods are in agreement with the geometry of X-ray crystallography available for comparison. B3LYP/cc-PVDZ level is particularly consistent with available X-ray crystallography in terms of predicting the geometries of FbC-M10Iso-Bn. Geometries of chlorin-imide and chlorin-isoimide isomeric pairs are described through B3LYP/cc-PVDZ method. The bond lengths of chlorin-isoimide, specifically C13–C14, C14–C15, and C2–C3, increase as bond overlap index decreases because of charge transfer. β-β bond lengths (C2–C3 bond lengths) with a three-substituent benzylcarbamoyl group also increase as bond overlap index decreases compared with other molecules. The bond lengths of chlorin-imide are smaller than those of chlorin-isoimide. Angles with β-β bond lengths, specifically C2–C3–C4 in ring A, also decrease with a three-substituent benzylcarbamoyl group; however, the angles in C1–C2–C3 increase. Potential energy on the surfaces of the chlorin-imide and chlorin-isoimide isomeric pairs is optimized by calculating the total and relative energies at B3LYP/cc-PVDZ level. Results indicate that chlorin-imides are more stable than chlorin-isoimides. Normal-coordinate structural decomposition shows that chlorin-imides exhibit greater deformation than chlorin-isoimides except for FbC-M10Iso-Ph.

π-Electron delocalization in 2-benzoyl-5-phenylpyrazolidin-3-one

2018 ◽  
Vol 73 (8) ◽  
pp. 577-582
Author(s):  
Monika Olesiejuk ◽  
Agnieszka Kudelko ◽  
Katarzyna Gajda ◽  
Błażej Dziuk ◽  
Krzysztof Ejsmont
Keyword(s):  
Hydrogen Bonds ◽  
Density Functional ◽  
Heterocyclic Ring ◽  
Molecular Structures ◽  
Electron Delocalization ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Benzene Rings ◽  
Subsequent Cyclization

AbstractThe crystal and molecular structures of 2-benzoyl-5-phenylpyrazolidin-3-one have been characterized by X-ray diffraction along with density functional theory studies. Cinnamic acid chloride was reacted with benzhydrazide, yielding 2-benzoyl-5-phenylpyrazolidin-3-one. This product was formed in the transformation comprising the nucleophilic addition of benzhydrazide to the styryl fragment of the α,β-unsaturated arrangement and subsequent cyclization. The molecule contains two benzene rings and one five-membered heterocyclic ring with an N–N single bond. The five-membered ring is composed of three atoms of sp3 hybridization and two atoms of sp2 hybridization, which cause the flattening of the heterocyclic ring. The Harmonic Oscillator Model of Aromaticity and Nucleus-Independent Chemical Shift indexes, calculated for the benzene rings, demonstrate that there are no substantial interactions between the regions of π-electron delocalization in the molecule. In the crystal structure, there are N–H···O hydrogen bonds that link the molecules along the crystallographic c axis and weak intermolecular C–H···O hydrogen bonds.

scholarly journals 2-{[Bis(propan-2-yl)carbamothioyl]sulfanyl}acetic acid

Molbank ◽  
10.3390/m1082 ◽  
2019 ◽  
Vol 2019 (4) ◽  
pp. M1082
Author(s):  
Lee ◽  
Azizan ◽  
Lo ◽  
Tan ◽  
Tiekink
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Acetic Acid ◽  
Density Functional ◽  
2D Nmr ◽  
Dft Methods ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography ◽  
Orthogonal Relationship

The title compound, (iPr)2NC(=S)SCH2C(=O)OH (1), was synthesized by conventional methods and its X-ray crystal structure was determined by X-ray crystallography. The compound was further characterized by analytical, IR, UV, 1D NMR (1H and 13C{1H}), and 2D NMR (DEPT-135) spectroscopy, and density functional theory (DFT) methods. X-ray crystallography on 1 confirms the formulation and reveals a nearly orthogonal relationship between the planar NCS2 and C2O2 residues. In the crystal, hydroxyl-O–H⋯O(carbonyl) hydrogen bonds lead dimers via an eight-membered {⋯OCOH}2 ring.

On the transferability of QTAIMC descriptors derived from X-ray diffraction data and DFT calculations: substituted hydropyrimidine derivatives

2011 ◽  
Vol 67 (5) ◽  
pp. 425-436 ◽  
Author(s):  
A. A. Rykounov ◽  
A. I. Stash ◽  
V. V. Zhurov ◽  
E. A. Zhurova ◽  
A. A. Pinkerton ◽  
...  
Keyword(s):  
Electron Density ◽  
Density Functional ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Covalent Bonds ◽  
Functional Theory ◽  
X Ray ◽  
Biginelli Compounds ◽  
Empirical Corrections

The combined study of electron-density features in three substituted hydropyrimidines of the Biginelli compound family has been fulfilled. Results of the low-temperature X-ray diffraction measurements and density functional theory (DFT) B3LYP/6-311++G** calculations of these compounds are described. The experimentally derived atomic and bonding characteristics determined within the quantum-topological theory of atoms in molecules and crystals (QTAIMC) were demonstrated to be fully transferable within chemically similar structures such as the Biginelli compounds. However, for certain covalent bonds they differ significantly from the theoretical results because of insufficient flexibility of the atom-centered multipole electron density model. It was concluded that currently analysis of the theoretical electron density provides a more reliable basis for the determination of the transferability of QTAIMC descriptors for molecular structures. Empirical corrections making the experimentally derived QTAIMC bond descriptors more transferable are proposed.

Synthesis and X-ray Studies of Novel Azaphenanthrenes

2018 ◽  
Vol 42 (2) ◽  
pp. 90-95 ◽  
Author(s):  
Adel S. Girgis ◽  
Marian N. Aziz ◽  
ElSayed M. Shalaby ◽  
Fahmy M. Asaad ◽  
I.S. Ahmed Farag
Keyword(s):  
Density Functional ◽  
Computational Studies ◽  
Stacking Interactions ◽  
Mean Square ◽  
Dft Methods ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography ◽  
Mean Square Errors ◽  
Ring Interaction

Two azaphenanthrenes were synthesised by a facile synthetic pathway and characterised by X-ray crystallography. Molecular packing of 4-(2,4-dichlorophenyl)-2-methoxy-5,6-dihydrobenzo[ h]quinoline-3-carbonitrile exhibits C–H…N and C–H…Cl hydrogen bonds in addition to intermolecular C–H…π, Cl…π and π…π (π-ring) stacking interactions. However, molecules of the 2-ethoxy derivative are linked into chains by one hydrogen bond of the C–H…N type and the crystal structure reveals an intermolecular C–H…π (π-ring) interaction. Computational studies by AM1, PM3, and density functional theory (DFT) techniques provide good approximations to the experimental X-ray data. The root mean square errors between the experimental and calculated bond lengths using AM1, PM3 and DFT methods for the 2-methoxy and 2-ethoxy derivatives are 0.0187, 0.0193, 0.0120 and 0.0197, 0.0195 and 0.0116 respectively.

Synthesis and structure of, and bonding in some derivatives of 2,6,9,10-tetraoxatricyclo[3.3.1.13,8]decane

2001 ◽  
Vol 57 (1) ◽  
pp. 63-71 ◽  
Author(s):  
J. Simons ◽  
H. G. Thomas ◽  
S. R. Hall ◽  
G. Raabe
Keyword(s):  
Density Functional ◽  
Correlation Energy ◽  
Single Point ◽  
Molecular Structures ◽  
Electrostatic Model ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Hartree Fock ◽  
Computational Quantum Chemistry ◽  
Derivatives Of

Five derivatives of 2,6,9,10-tetraoxatricyclo[3.3.1.13,8]decane were synthesized and their molecular structures in the solid state were determined by means of X-ray diffraction analysis. In addition, the structures of all the molecules were optimized at different levels of computational quantum chemistry (HF/6-31G*, B3LYP/6-31G*). Experimentally determined bond lengths were compared with their calculated counterparts, and striking differences between the Hartree–Fock (HF) results and the experimental data could be traced back to the lack of correlation energy in the geometry optimizations. Two of the compounds under consideration are diastereomers and their relative stability was not only calculated with a conventional ab initio method (ZPE+MP2/6-31G*//HF/6-31G*), but also within the framework of density functional theory (B3LYP/6-31G*). In some of the calculations the influence of the solvent was included in single point calculations by means of an electrostatic model. Moreover, combining experimental as well as computational results, the exclusive axial orientation of a Cl atom in one of the compounds could be explained by an interplay of kinetic and energetic effects.

Triclinic conformational polymorph of N,N,N′,N′-tetrakis(2-cyanoethyl)-1,2-ethylenediamine (TCED)

2018 ◽  
Vol 73 (5) ◽  
pp. 305-309
Author(s):  
Bartłomiej Bereska ◽  
Krystyna Czaja ◽  
Błażej Dziuk ◽  
Bartosz Zarychta ◽  
Krzysztof Ejsmont ◽  
...  
Keyword(s):  
Density Functional ◽  
Crystalline State ◽  
Polymeric Materials ◽  
Molecular Geometry ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Homologous Compounds

AbstractThe crystal and molecular structures of two polymorphs of N,N,N′,N′-tetrakis(2-cyanoethyl)-1,2-ethylenediamine have been characterized by X-ray diffraction along with density functional theory (DFT) studies. The molecules differ from each other by conformation. N,N,N′,N′-tetrakis(2-cyanoethyl)-1,2-ethylenediamine has been synthesized by cyanoethylation of ethylenediamine. Cyanoethylation of vicinal diamines is important for the synthesis of hyperbranched polymeric materials applied as catalysts, surfactants and encapsulating agents in drug delivery systems. The molecular geometry of N,N,N′,N′-tetracyanoethyl-1,2-ethylenediamine is similar to that of homologous compounds. DFT calculations were performed to analyze the differences in the molecular geometry of the studied compounds in a crystalline state and for an isolated molecule.

Highly Electron-Deficient Pyridinium-Nitrones for Rapid and Tunable Inverse-Electron-Demand Strain-Promoted Alkyne-Nitrone Cycloaddition to Bicyclo[6.1.0]nonyne

2019 ◽  
Author(s):  
Praveen Gunawardene ◽  
Wilson Luo ◽  
Alexander M. Polgar ◽  
John F. Corrigan ◽  
Mark Workentin
Keyword(s):  
Density Functional Theory ◽  
Reaction Kinetics ◽  
Density Functional ◽  
Functional Theory ◽  
X Ray ◽  
Inverse Electron Demand ◽  
X Ray Crystallography ◽  
Electron Demand

<div> <div> <p>Highly accelerated inverse-electron-demand strain-promoted alkyne-nitrone cycloaddition (IED SPANC) between a sta- ble cyclooctyne (bicyclo[6.1.0]nonyne (BCN)) and nitrones delocalized into a Cα-pyridinium functionality is reported, with the most electron-deficient “pyridinium-nitrone” displaying among the most rapid cycloadditions to BCN that is currently reported. Density functional theory (DFT) and X-ray crystallography are explored to rationalize the effects of N- and Cα-substituent modifications at the nitrone on IED SPANC reaction kinetics and the overall rapid reactivity of pyridinium-delocalized nitrones.</p> </div> </div>

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