Crystal Structure Optimization and Semi-Empirical Quantum Chemical Calculations of N-(3,4-Dichlorophenyl)-3-Oxo-Butanamide

2012 ◽  
Vol 620 ◽  
pp. 82-86
Author(s):  
Mukesh M. Jotani
Keyword(s):  
Crystal Structure ◽  
Molecular Electrostatic Potential ◽  
Crystal Packing ◽  
Empirical Method ◽  
Molecular Orbital Calculations ◽  
X Ray ◽  
Semi Empirical ◽  
Packing Interactions ◽  
Optimized Geometries ◽  
Good Agreement

The crystal structure of N-(3,4-Dichlorophenyl)-3-oxobutanamide (I) is optimized by semi-empirical methods using MOPAC2009 program. The optimized geometries from both Austin Model 1 (AM1) and Parametrization Model 6 (PM6) describe the conformational discrepancy and crystal packing. The energy minimized structures from both the models are in good agreement with X-ray crystal data. The intramolecular charge transfer interactions are studied from the molecular orbital calculations. The parametric molecular electrostatic potential (PMEP) calculated by AM1 semi-empirical method shows the involvement of oxygen and chlorine atoms in the crystal packing interactions. The aromaticity of phenyl ring in the structure is determined using HOMED calculations.

Crystal structure and nonlinear optical properties of 7,8-dihydroxyaminoacenaphthalene

2017 ◽  
Vol 26 (01) ◽  
pp. 1750003 ◽  
Author(s):  
Meng-Xiao Niu ◽  
Chao-Zhi Zhang
Keyword(s):  
Crystal Structure ◽  
Optical Materials ◽  
Nonlinear Optical ◽  
Empirical Method ◽  
Nonlinear Optical Materials ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Title Molecule ◽  
Semi Empirical

In this paper, 7,8-dihydroxyaminoacenaphthalene was synthesized by a convenient method. Its crystal structure was determined by X-ray diffraction. The crystal structure shows that the molecules aggregated to monoclinic crystal with space group [Formula: see text]. The semi-empirical method ZINDO was employed to study the static first hyperpolarizabilities of this compound. The static first hyperpolarizability value is [Formula: see text][Formula: see text]esu, which is 6.00 times as much as that of KH2PO4 (KDP) molecule. The results indicate that the title molecule would be potential nonlinear optical materials.

Crystal Structure Optimization and Semi-Empirical Quantum Chemical Calculations of Fused Bicyclic Heterocycles

2015 ◽  
Vol 1087 ◽  
pp. 59-63
Author(s):  
Mukesh M. Jotani
Keyword(s):  
Molecular Orbital ◽  
Crystal Packing ◽  
Linear Regression Analysis ◽  
Empirical Method ◽  
Highest Occupied Molecular Orbital ◽  
Phenyl Rings ◽  
Lowest Unoccupied Molecular Orbital ◽  
Semi Empirical ◽  
Crystal Packing Effects ◽  
Packing Interactions

The crystal structures of two fused pyridine derivatives viz Ethyl 3-amino-6-phenyl-4-tolylfuro[2,3-b]pyridine-2-carboxylate (I) and Ethyl 3-amino-6-phenyl-4-tolylthieno[2,3-b] pyridine-2-carboxylate (II) were optimized by semi-empirical methods using MOPAC2009 program. The geometries optimized for both the structures from Austin Model 1 (AM1) and Parametrization Model 6 (PM6) describe the conformational discrepancy and crystal packing effects. The parametric molecular electrostatic potential (PMEP) calculated by AM1 semi-empirical method describe the involvement of nitrogen and oxygen atoms in the crystal packing interactions in both the structures. The frontier molecular orbitals highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) indicate the intramolecular charge transfer interactions. The HOMED indices computed for the phenyl rings in the structures describe the p-electron delocalization. The linear regression analysis shows good correlation between experimental and theoretical structures.

Study on a Novel Structure of Zn Phenanthroline Malic Acid Hydrate, [Zn (C12H8N2)(C4H4O5)(H2O)](H2O)

2013 ◽  
Vol 739 ◽  
pp. 26-29
Author(s):  
Hai Xing Liu ◽  
Jing Zhong Xiao ◽  
Huan Mei Guo ◽  
Qing Hua Zhang ◽  
Zhang Xue Yu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Malic Acid ◽  
Hydrothermal Reaction ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
Acid Anion ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Novel Structure ◽  
Acid Hydrate

A novel Zn complex [Zn (C12H8N2)(C4H4O5)(H2O)](H2O) has been synthesized from a hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Zn atom is six-coordinated by two phenanthroline N atoms, three O atoms from malic acid anion and one O atom from water. The crystal packing is stabilized by O-H...O hydrogen bonding interactions.

4-(Bromomethyl)benzophenone

2007 ◽  
Vol 63 (3) ◽  
pp. o1188-o1189 ◽  
Author(s):  
Wei-Jian Xu ◽  
Yang-Ling Zang ◽  
Guo-Liang Wu ◽  
Sheng-Pei Su ◽  
De-Yue Qiu
Keyword(s):  
Crystal Structure ◽  
Carbon Tetrachloride ◽  
Dihedral Angle ◽  
Structure Analysis ◽  
Title Compound ◽  
Crystal Packing ◽  
Crystal Structure Analysis ◽  
X Ray ◽  
Compound C ◽  
Phenyl Rings

The title compound, C14H11BrO, was synthesized by the reaction of 4-methylbenzophenone and bromine in carbon tetrachloride. X-ray crystal structure analysis reveals that the benzene and phenyl rings form a dihedral angle of 59.53 (6)°, and the crystal packing is stabilized by intermolecular C—H...π interactions.

scholarly journals Preparation of pyridine-3,4-diols, their crystal packing and their use as precursors for palladium-catalyzed cross-coupling reactions

2010 ◽  
Vol 6 ◽  
Author(s):  
Tilman Lechel ◽  
Irene Brüdgam ◽  
Hans-Ulrich Reissig
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Cross Coupling ◽  
Crystal Structure Analysis ◽  
Coupling Reactions ◽  
X Ray ◽  
Cross Coupling Reactions ◽  
Fluorescence Measurements ◽  
Subsequent Conversion ◽  
Palladium Catalyzed

A series of trifluoromethyl-substituted 3-alkoxypyridinol derivatives has been deprotected to furnish pyridine-3,4-diol derivatives in good yields. The X-ray crystal structure analysis proved that a 1:1 mixture of pyridine-3,4-diols and their pyridin-4-one tautomers exist in the solid state. Subsequent conversion into bis(perfluoroalkanesulfonate)s were smoothly achieved. The obtained compounds were used as substrates for palladium-catalyzed coupling reactions. Fluorescence measurements of the biscoupled products showed a maximum of emission in the violet region of the spectrum.

scholarly journals Surface Engineering of Top7 to Facilitate Structure Determination

2022 ◽  
Vol 23 (2) ◽  
pp. 701
Author(s):  
Yuki Ito ◽  
Takuya Araki ◽  
Shota Shiga ◽  
Hiroyuki Konno ◽  
Koki Makabe
Keyword(s):  
Structure Determination ◽  
Surface Engineering ◽  
De Novo ◽  
Crystal Packing ◽  
Structure Model ◽  
X Ray ◽  
Hexahistidine Tag ◽  
Model Protein ◽  
Β Sheet ◽  
Packing Interactions

Top7 is a de novo designed protein whose amino acid sequence has no evolutional trace. Such a property makes Top7 a suitable scaffold for studying the pure nature of protein and protein engineering applications. To use Top7 as an engineering scaffold, we initially attempted structure determination and found that crystals of our construct, which lacked the terminal hexahistidine tag, showed weak diffraction in X-ray structure determination. Thus, we decided to introduce surface residue mutations to facilitate crystal structure determination. The resulting surface mutants, Top7sm1 and Top7sm2, crystallized easily and diffracted to the resolution around 1.7 Å. Despite the improved data, we could not finalize the structures due to high R values. Although we could not identify the origin of the high R values of the surface mutants, we found that all the structures shared common packing architecture with consecutive intermolecular β-sheet formation aligned in one direction. Thus, we mutated the intermolecular interface to disrupt the intermolecular β-sheet formation, expecting to form a new crystal packing. The resulting mutant, Top7sm2-I68R, formed new crystal packing interactions as intended and diffracted to the resolution of 1.4 Å. The surface mutations contributed to crystal packing and high resolution. We finalized the structure model with the R/Rfree values of 0.20/0.24. Top7sm2-I68R can be a useful model protein due to its convenient structure determination.

Study on Novel Structure of Praseodymium Complex, C5H13O11Pr

2013 ◽  
Vol 834-836 ◽  
pp. 515-518
Author(s):  
Hai Xing Liu ◽  
Qing Liu ◽  
Ting Ting Huang ◽  
Yang Xu ◽  
Lin Tong Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Single Crystal ◽  
Hydrothermal Reaction ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Novel Structure ◽  
Praseodymium Complex

A novel praseodymium complex C5H13O11Pr has been synthesized from hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Pr1 atom is nine coordinated by nine O atoms. The crystal packing is stabilized by O-H...O hydrogen bonding interactions.

Intraionic Structure of HS04- and Alkali Cation Configuration in Molten NaHS04 and KHS04

1994 ◽  
Vol 49 (7-8) ◽  
pp. 785-789 ◽  
Author(s):  
K. Fukushima ◽  
M. Murofushi ◽  
M . Oki ◽  
K. Igarashi ◽  
J. Mochinaga ◽  
...  
Keyword(s):  
Molten Salts ◽  
Molecular Orbital Calculations ◽  
Distorted Tetrahedron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths ◽  
Semi Empirical ◽  
Polyatomic Anion ◽  
Short Range Structure

Abstract The short range structure of molten NaHSO4(I) and KHSO4(II) was estimated by X-ray diffraction. The polyatomic anion, HSO4-, in both molten salts was found to have a distorted tetrahedral structure in which the bond lengths of S-O and S-OH were 1.45 Å and 1.53 Å in (I) and 1.46 Å and 1.56 Å in (II), respectively. The coordination number of the Na+ or K+ around the HSO4- was evaluated to be about unity. The semi-empirical molecular orbital calculations by the MNDO-MOPAC method were applied to the determination of the intraionic structure of the H S 0 4 and the bond lengths of S-O and S -OH were computed to be 1.528 Å and 1.666 Å, respectively, supporting qualitatively that the HSO4- forms a rather distorted tetrahedron.

Darstellung, Schwingungsspektren und Normalkoordinatenanalyse der 10B-und 11B-Isotopomeren von [B2(NCS)6]2- sowie Kristallstruktur von (Ph3P=N=PPh3)2[B2(NCS)6] / Preparation, Vibrational Spectra and Normal Coordinate Analysis of the 10B and 11B Isotopomers of [B2(NCS)6]2- and Crystal Structure of (Ph3P=N=PPh3)2[B2(NCS)6]

1996 ◽  
Vol 51 (4) ◽  
pp. 551-556 ◽  
Author(s):  
W. Preetz ◽  
B. Steuer
Keyword(s):  
Crystal Structure ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Triclinic Space Group ◽  
X Ray ◽  
Fractionated Crystallization ◽  
Good Agreement

Abstract By reaction of [B6H6]2- with a solution of (SCN)2 in dichloromethane in the presence of solid KOH the hexaisothiocyanatodiborate anion [B2(NCS)6]2- is formed and can be isolated by fractionated crystallization. The crystal structure of (PNP)2[B2(NCS)6] has been determined by single crystal X-ray diffraction analysis; triclinic space group P1̄ with a=12,282(5), b=12,416(5), c=14,155(5)Å, a=68,36(5), β=70,59(5), γ=80,93(5)°.The [B2(NCS)6]2- anion reveals a staggered conformation with nearly local D3d symmetry and a B-B bond length of 1,73(2) Å. Using the crystallographic data a normal coordinate analysis has been performed. With a set of 12 force constants (e.g. fd(BB)=3,62, fd(BN)=4,21 mdyn/Å) a good agreement between observed and calculated frequencies for the 10B and 11B isotopomers has been achieved. The potential energy distribution on the force constants reveals strong vibrational couplings within the B2N6 framework.

scholarly journals X-ray Single-Crystal Structural Analysis of a Magnetically Oriented Monoclinic Microcrystal Suspension of α-Glycine

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 561 ◽  
Author(s):  
Tatsuya Tanaka ◽  
Chiaki Tsuboi ◽  
Kazuaki Aburaya ◽  
Fumiko Kimura ◽  
Masataka Maeyama ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Magnetic Energy ◽  
Powder Sample ◽  
Single Crystal Structure ◽  
X Ray ◽  
Crystal Structural ◽  
The Relationship ◽  
Good Agreement

We previously reported on a method for X-ray single-crystal structure determination from a powder sample via a magnetically oriented microcrystal suspension (MOMS). The method was successfully applied to orthorhombic microcrystals (L-alanine, P212121). In this study, we apply this method to monoclinic microcrystals. Unlike most of the orthorhombic MOMSs, monoclinic MOMSs exhibit two or four orientations with the same magnetic energy (we refer to this as twin orientations), making data processing difficult. In this paper, we perform a MOMS experiment for a powder sample of monoclinic microcrystal (α-glycine, P21/n) to show that our method can also be applied to monoclinic crystals. The single-crystal structure determined in this work is in good agreement with the reported one performed on a real single crystal. Furthermore, the relationship between the crystallographic and magnetic susceptibility axes is determined.

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