Crystal and electronic structure of heteromolecular complexes of 3,6-bis(3,5-dymethylpyrazole-1-yl)-1,2,4,5-tetrazine with azoles

X-ray crystallography is used to investigate heteromolecular crystals of 3,6-bis(3,5-dimethylpyrazole-1-yl)-1,2,4,5-tetrazine with NH-donating azole derivatives. The effect is studied of the structure of azole on molecular packing in the crystal and the characteristics of covalent bonds in the molecule of 3,6-disubstituted tetrazine. The distribution of electron density critical points inside crystal cells is analyzed to identify and quantitatively describe the intermolecular interactions underlying the formation of lateral and stacking motifs.     

Crystal and molecular structure of the complex of 2-(1-silatranylmethylthio)-4,5-benzo-1,3-thiazole with CoCl2 and MeCN

The crystal and molecular structure of the complex of 2-(1-silatranylmethylthio)-4,5-benzo-1,3-thiazole with CoCl₂ and MeCN (I) is determined by single crystal X-ray diffraction. The geometry of the silatranylmethyl moiety in complex I is compared to the geometry of 1-(2′-benzthiazolylthiomethyl) silatrane. Molecular packing in the crystal is analyzed.     

Crystal and molecular structure of 3,4,4,5-tetramethyl-1-(p-methoxybenzoyl)-5-(p-methoxybenzoylazo)-2-pyrazoline

The crystal and molecular structure of the title compound, derived by lead tetraacetate oxidation of the bis-p-methoxybenzoylhydrazone of 3,3-dimethylpentane-2,4-dione, is studied by an X-ray crystallographic analysis.     

Synthesis,crystal structure,and density functional theory study of a new compound 4-(2-chlorobenzyl)-1-(5-fluoro-2-hydroxy-3-(thiomorpholinomethyl)phenyl [1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one

In this paper, a novel SHP244 derivative 4-(2-chlorobenzyl)-1- (5-fluoro-2-hydroxy-3- [thiomorph-olinomethyl] phenyl)- [1,2,4]triazolo [4,3-a] quinazolin-5(4H)-one was synthesized through five steps. The single crystals were grown in a suitable solvent system (dichloromethane and methanol). Its structure was confirmed by ¹H NMR, ¹³C NMR spectroscopy, ESI-MS, m/z: 534.12[M-H] (MS), FT-IR, and X-ray single crystal diffraction. The crystal structure of the title compound was optimized by density functional theory (DFT) calculation. The crystal structure after X-ray single crystal diffraction was compared with the structure optimized by DFT calculation, and the result shows that the two structures are consistent. In order to explore certain physical and chemical properties, the frontier molecular orbital and molecular electrostatic potential of the title compound were analyzed. In addition, the docking of the title compound to the target protein was studied to understand the docking effect of the compound with the target protein.     

Protolytic Properties and Molecular Structure of 2,8,14,20-Tetramethyl-5,11,17,23-tetrakis(N-morpholino)- methylcalix[4]resorcinolarene

The protolytic properties of 2,8,14,20-tetramethyl-5,11,17,23-tetrakis(N-morpholino)methylcalix[4]resorcinolarene were studied by pH-potentiometric titration. Its crystal and molecular structure was determined by single crystal X-ray diffraction and UV spectroscopy. In solution the macrocycle exists as a zwitter-ion. In the crystal, the calixresorcinolarene molecule is in the cone conformation; two pairs of the opposite morpholine substituents are oriented inside and outside the macrocycle cavity and therefore show different acid properties.     

Synthesis and structural study of N′-(4,6-diphenylpyrimidin-2-yl)-2-methylpropanoic hydrazide

Reaction of 1-(4-methoxyphenyl)-3-isopropyl-5-(4,6-diphenylpyrimidin-2-yl)formazan with nickel nitrate in acid medium yields N′-(4,6-diphenylpyrimidin-2-yl)-2-methylpropanoic hydrazide. Its crystal and molecular structure is studied by single crystal X-ray diffraction.     

Monomeric cis-isothiocyanato complexes. Crystal and molecular structure of [Mn(mep)2(NCS)2] (mep=4-methoxy-2-(5-methoxy- 3-methyl-1H-pyrazol-1-yl)-6-methylpyrimidine)

The crystal and molecular structures of [Mn(mep)2- (NCS)2] ({ {mep}}=4-methoxy-2-(5-methoxy-3-methyl-1H-pyrazol-1-yl)-6-methylpyrimidine) have been determined by X-ray crystallography. The crystal structure of the title compound is built up of isolated [Mn(mep)2(NCS)2] molecules with the stereochemistry of a distorted octahedron for the MnN6 chromophore. The e.p.r. (Q-band) data are in agreement with the structural data.     

Vibrational spectra and normal coordinate analysis of a weak ligand complex, Co(p-DMABA)2Cl2 x 2H2O.

The complex Co(p-DMABA)2Cl2 x 2H2O (p-dimethylaminobenzaldehyde, p-DMABA) was prepared from the solid-state reaction of a weak ligand p-DMABA and CoCl2 x 6H2O at lower heating temperature (60 degrees C). It is very difficult to obtain the title complex using solution reaction method, less than isolating single crystals. In order to determine the crystal structure of the title compound, we have to rely on the X-ray powder diffraction data. That is, the crystal structure can be solved directly from powder data, which crucial step is to constitute the structure model. Indirect spectroscopic methods, such as infrared and Raman spectroscopes, and further vibrational assignments made with the aid of normal coordinate calculations by using a modified Urey-Bradley force field, were analyzed to proposed molecular structure. One hundred and fifty-seven internal coordinates were established and 129 theoretical vibrational frequencies were calculated. An appropriate set of internal coordinates and force constants in the course of calculation were introduced, so that the calculated vibration frequencies are good agreement with the observed values. The average difference and the maximum deviation between theoretic and experimental frequencies are 2.44 and 8.0 cm(-1), respectively. Thus the normal coordinate analysis is a powerful tool to the molecular structure. Other structural and spectral properties are also discussed in this paper. The purpose of the present paper is to obtain a good structural model. This model was used as starting model for crystal structure determination from powder X-ray diffraction (XRD) data.     

Crystal and Molecular Structure of 2H- and 2-(p-Tolylamino)-5,6-dimethylthieno[2,3-d]pyrimidin-4-ones

The crystal and molecular structure of 2H- and 2-(p-tolylamino)-5,6-dimethylthieno[2,3-d]pyrimidin-4-ones was investigated by X-ray diffraction. In crystals, the tautomeric form with a localized N(1)=C(2) bond is realized. A comparative analysis of the two structures using the literature data is given to examine the conjugation effect on the geometrical parameters of a pseudoaromatic pyrimidine system.     

Synthesis of enantiomeric menthol derivatives for forming and probing chiral surfaces. X-ray crystal and molecular structures of (+)-(1S,2R,5S)-1-(2-tricyanovinyl-1H-pyrrol-1-yl-methoxy)-2-isopropyl-5-methylcyclohexane

Two enantiomeric pairs of menthol derivatives, the menthol ester with 10-undecynoic acid and the 2-tricyanovinyl-pyrrole derivative of the methoxy-menthol, have been synthesized and their pure enantiomers obtained. The X-ray crystal and molecular structure of the (+)-enantiomer of the latter compound is reported.     

2-(2′-苯基丙烯基)苯并噁唑类化合物的合成及晶体结构

合成了11种2-(2′-苯基丙烯基)苯并噁唑类和9种2-(2′-苯基丙烯基)-5-甲基苯并噁唑类化合物。测定了它们的熔点、元素分析、红外光谱及个别衍生物的核磁共振谱和X射线单晶分析,确证了这类化合物的分子结构。     

Synthesis and Structure of Some N-[3-(Het)aryl-2-propenylidene]trifluoromethylanilines

The reactions of 4-nitrocinnamaldehyde with trifluoromethylanilines in the presence of molecular sieves were studied, and a series of new aromatic and heterocyclic aldimines were synthesized. The molecular and crystal structure of some of them were determined by X-ray crystallographic analysis.     

PM3 semiempirical study and its comparison with X-ray crystal structure of 2-methyl-4-(4-methoxyphenylazo)phenol

The crystal and molecular structure of 2-methyl-4-(4-methoxyphenylazo)phenol have been determined by X-ray single crystal diffraction technique. The compound crystallizes in the monoclinic space group P2₁/c with a=9.7763(8) Å, b=11.3966(8) Å, c=11.9531(8) Å and β=108.752(6)°. In addition to the molecular geometry from X-ray experiment, its optimized molecular structure has been obtained with the aid of PM3 semiempirical quantum mechanical method, and then the corresponding geometric parameters were compared with those of X-ray crystallography. To determine conformational flexibility and crystal packing effects on the molecules, molecular energy profile of the title compound was obtained with respect to two selected degrees of torsional freedom, which were varied from ?180° to +180° in steps of 10°. Crystal structure of the title compound is a fibroid structure constructed by C–H···O and O–H···N type intermolecular hydrogen bonds. The most favorable conformer of the title compound has been determined by the crystal packing effects and there is no steric hindrance during rotation around the selected torsion angles.     

Crystal structure and DFT calculations of methanol {E-N′-(2-hydroxybenzlidene)benzohydrazido}dioxidomolybdenum (VI) complex

The crystal and molecular structure of methanol {E-N′-(2-hydroxybenzlidene)benzohydrazido}dioxidomolybdenum (VI) was determined by single crystal X-ray diffraction. B3LYP/DZP basis set theoretical calculations nicely reproduce the X-ray experimental geometry. The obtained results are discussed in connection with the electronic and structural properties of the compound.     

Crystal structure of copper(II) 2-methyl-3-{[3-methyl-5-oxo-1-phenylpyrazole-4-ylidene-methyl]amino}-quinazoline-4-onate

The crystal and molecular structure of a copper(II) complex based on 2-methyl-3-{[3-methyl-5-oxo-1-phenylpyrazole-4-ylidene-methyl]amino}-quinazoline-4-one is studied by single crystal X-ray diffraction. The chelate core is demonstrated to have a pyramidal structure.     

Synthesis and Alkylation of 4-(2-Chlorophenyl)-3-cyano-6-hydroxy-5-(2-thienoyl)-6-trifluoromethylpiperidin-2-thione

4-(2-Chlorophenyl)-3-cyano-6-hydroxy-5-(2-thienoyl)-6-trifluoromethylpiperidin-2-thione, which was used for the synthesis of 2-allylthio-4-(2-chlorophenyl)-3-cyano-6-hydroxy-5-(2-thienoyl)-6-trifluoromethyl-1,4,5,6-tetrahydropyridine, was obtained by the reaction of 2-thienoyltrifluoroacetone with 2-chlorophenylphenylmethylenecyanothioacetamide or with a mixture of 2-chlorobenzaldehyde and cyanothioacetamide in the presence of N-methylmorpholine. The molecular and crystal structure of the piperidinthione have been established by X-ray crystallography.     

Enantioselective Copper-Catalyzed 1,4-Addition of Grignard Reagents to α,β-Unsaturated Carbonyl Compounds

The enantioselective copper-catalyzed 1,4-addition of Grignard reagents to α,β-unsaturated carbonyl compounds was studied with the following Cu^I compounds as catalyst precursor and 1,2:5,6-di-O-isopropylidene-3-thio-α-D -glucofuranose (Hsiig) as chiral ligand: CuI, iodo[bis(dibutylsulfide)]copper(I), [Cu(siig)], [Cu(siig)(pp)] (pp =1,2-bis)(diphenylphosphinoethene), and tetrakis[iodo(tributylphosphine)]copper(I). The addition of BuMg halides to cyclohex-2-en-1-one was tested under several reaction conditions. The chemical yields and regioselectivities for this reaction were, in all cases, larger than 90 and 98%, respectively, and independent of the experimental conditions. The enantioselectivity was strongly dependent on the reaction conditions and reached a maximum of 60%. Several other substrates were also tested in the above reaction. The X-ray crystal structure for [Cu(siig)(pp)] was determined by X-ray crystallography.     

Effect of Substituents on the Supramolecular Structure and Stability of Crystals of Dialkylaminomethylated Calix[4]resorcinolarenes

The crystal and molecular structure of previously unknown dimethyl- and diethylaminomethylated calix[4]resorcinolarenes was determined by X-ray diffraction. The calixarene molecules occur in the crystal in the coneform, stabilized by the system of hydrogen bonds at the upper rim of the macrocycle. The crystal structure of the dimethylaminomethylated derivative includes 4.5 benzene molecules and an ethanol molecule per calixarene molecule. No solvent molecules are located inside the macrocycle cavity. In the structure of the diethylaminomethylated derivative there is one benzene molecule per calixarene molecule. The benzene molecule is located in the macrocycle cavity. The supramolecular structure of crystals is analyzed.