Mesomorphic Properties of the 4-(4-n-Alkoxybenzoyloxy)-Benzylidene-4-n-Alkoxyanilines and 4-(4-n-Alkoxybenzoyloxy)-3-Methoxy-Benzylidene-4-n-Alkoxyanilines

Transition temperatures, transition enthalpies and X-ray results are reported for 4-(4-n-heptyloxybenzoyloxy)-benzylidene-4-n-alkoxyanilines, 4-(4-n-nonoxybenzoyloxy)-benzylidene-4-n-alkoxyanilines and their 3-methoxy-benzylidene substituted derivatives.     

Conformational polymorphism of N-(4-butoxyphenyl)-4-(4′-nitrophenyl)-2-thiazolamine

Crystallography Reports - The molecular and crystal structures of three concomitant polymorphic modifications of N-(4-butoxyphenyl)-4-(4′-nitrophenyl)-2-thiazolamine are investigated by X-ray...     

Synthesis and X-ray structure of 3-(4-methyl phenyl)-2-(4-biphenyl)-1,3-thiazolidin-4-one

The title compound (C₂₂H₁₉NOS) was synthesized, characterized and structure was determined by X-ray diffraction method. It crystallizes in the monoclinic space group P2₁/c with cell parameters a = 22.181(2) Å, b = 6.0760(4) Å, c = 13.349(3) Å, = 95.615(3)^, and {Z = 4}. The final residual factor is 0.0625 for 1724 reflections with I > 2(I). 4-thiazolidinone ring moiety shows twisted conformation.     

4-(1,4-Dimethoxy-2-naphthyl)-4- hydroxycyclohexanone and its ethylene ketal

Intramolecular hydrogen bonding in the solid state is reported for the title compound and its ethylene ketal. The title compound crystallizes in the triclinic space group, with a = 9.590(3), b = 9.620(3), c = 9.844(2) Å, = 97.67(2), = 105.25(2), = 115.47(2), and Z=2. The ethylene ketal crystallizes in the monoclinic space group, P2₁/c, with a = 7.230(2), b = 22.639(3), c = 10.839(2) Å, = 101.47(2), and Z = 4. The intramolecular hydrogen bond length of 1.79 Å is the same for the ketone and ketal, but the O—H---O valence angle is 144° for the ketone and 165° for the ketal.     

Calorimetric investigations of 2-[4-n-alkylphenyl]-5-[4-n-alkyloxyphenyl]-pyrimidines

We investigated temperatures and enthalpies of the phase transitions by means of the calorimeter DSC-2. The kinetics of polymorphic transitions in the solid state, the pretransitional behaviour in the liquid crystalline phases and the transition enthalpies, ranging from 3 J/mol up to 50 kJ/mol, in relation to the occurrence of the liquid crystalline phase types S_G, S_F, S_C, S_A, and N are points of discussion.     

Synthesis and Molecular Structure of 2-(4-Chlorophenyl)-3-(phenyl-amino)-5-(thiophen-2-ylmethylidene)-3,5-dihydro-4H-imidazol-4-one

Crystallography Reports - 2-(4-Chlorophenyl)-3-(phenylamino)-5-(thiophen-2-ylmethylidene)-3,5-dihydro-4H-imidazol-4-one, C20H14N3OSCl was synthesized and its crystal structure was determined by...     

4- and 5-nitroindane

Mononitration of indane produces a mixture of 4- and 5- nitroindanes. Crystallization from mixtures occurs after distillation improves composition of a major component to above 80%. 4-Nitroindane: triclinic, space group (#2),a=7.332(4) Å,b=8.304(4) Å,c=8.358(4) Å, =61.43(4)°, =67.60(4)°, =70.15(4)°,V=405.4(4) ų,Z=2. Non-H-atoms are nearly planar, aliphatic H's are eclipsed. 5-Nitroindane: monoclinic, space groupP2₁/c (#14),a=10.946(8) Å,b=15.643(10) Å,c=9.415(6) Å, =92.34(5)°,V=1611(2) ų,Z=8. Non-H-atoms in the two molecules differ in torsion of the nitro group with respect to indane and fold of the nonbenzylic methylene group. Semiempirical calculations (PM3) suggest that distorsion from planarity may be associated with the two lowest energy vibrational modes. Uv, ir, ms, proton, and¹³C-nmr spectra are correlated with the solid state structures.     

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.     

The structure of ethyl allyl 1,4-dihydro-2,6-dimethyl-4-[4-(4H-4-oxo-1-benzopyran-2-yl)phenyl]-3,5-pyridine dicarboxylate

The crystal and molecular structure of the title compound has been determined by direct methods, and refined to a finalR of 0.070 for 1466 observed reflections. The compound crystallizes in space group P2_l/n with cell dimensionsa=10.706(8),b=21.127(11),c=12.038(10) Å, Z=4.1,4-dihydropyridine ring adopts a boat shaped conformation. The flavon molecule is planar and it's phenyl ring is almost perpendicular to the 1,4-DHP. The C36 atom of the allyl group shows disorder.     

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.     

X-ray structure of isomeric 3-chloro-4-(methylthio)- and 4-chloro-3-(methylthio)quinolines

The crystal and molecular structures of two isomeric 3,4- and 4,3-chloro-(methylthio)quinolines have been determined. For 3-chloro-4-(methylthio)-quinoline (3-Cl–4-MeS–Q); triclinic, space group ,a=7.199(3),b=7.919(3),c=8.921(3) Å, =89.74(3), =74.29(3), =78.55(3)°. For 4-chloro-3-(methylthio)quinoline (4-Cl–3-MeS–Q): monoclinic, space group P2₁/n,a=12.860(4),b=5.424(2),c=13.434(4) Å, =90.84(3)°. The values of the Cl...S distance as well as those for the Cl–C–C(S) and (Cl)C–C–S angles indicate the attractive interaction between ortho-situated heteroatoms in isomer 4-Cl–3-MeS–Q contrary to the effects observed in the case of 3-Cl–4-MeS–Q. The conclusions were confirmed by calculations of atomic charges withab initio method 4-31G basis set, which show positively charged sulfur atom in 4-Cl–3-MeS–Q and negatively charged sulfur in 3-Cl–4-MeS–Q.Part XXX in the series of Azinyl Sulfides.     

Mesomorphic Properties of Di- (4 - Alkoxyphenyl) and Di- (4 - Alkanoyloxyphenyl) Tetrathiafulvalenes

The polymorphism of the di- (4 - alkoxyphenyl) and di- (4 - alkanoyloxyphenyl) tetrathiafulvalenes (TTF) is investigated. In the dialkoxy series, the short chain derivative exhibits a smectic G phase and a nematic phase. The latter phase disappears in the long chain derivative. The dialkanoyloxy derivatives exhibit a smectic G phase (for short chains) and a smectic C phase (for long chains). A plot of the mesormorphic-isotropic transition temperatures against the number of carbon atoms of the substituent shows the usual odd-even effect. Some tetra (alkoxyphenyl) tetrathiafulvalenes are described, unfortunately they have no mesomorphic properties.     

Synthesis and Crystal Structure of [2-(4-chlorobenzoyloxy)-5-methylphenyl]-(4-methylphenyl)methanone

[2-(4-Chlorobenzoyloxy)-5-methylphenyl]-(4-methylphenyl)methanone was synthesized and characterized by spectroscopic and X-ray diffraction methods. The molecule crystallizes in the monoclinic space group P2₁/c with cell parameters a = 13.7530(19) Å, b = 10.0560(19) Å, c = 13.469(3) Å, β = 100.630(7)° and Z = 4. There is a large discrepancy between the carbonyl group bond lengths of ketone and the ester. The structure exhibits intermolecular hydrogen bonds of the type C–H···O.     

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.     

X-ray structure analysis of 1-(4-bromophenyl)-3-(4-chlorophenyl)-prop-2-en-1-one

The title compound crystallizes in the monoclinic space group P2₁/c with unit cell parameters a = 15.6239(15) ?, b = 14.0537(14) ?, c = 5.8396(5) ?, β = 92.666(3)°, V = 1280.8 (2) ?³, and Z = 4. The final reliability index is 0.0538 for 2921 observed reflections. Two phenyl rings of the title molecule are not coplanar, with a dihedral angle of 46.3(0)°. The molecular planarity of this substituted chalcone is strongly affected by the 4′-bromo group. The crystal cohesion is accentuated by π···π, C–H···Br interactions and R₃ ¹ (11) hydrogen bond.     

Crystal Structure of 1,7-Bis(4-chlorophenyl)-4-(1,3-dithiolan-2-ylidene)-1,6-heptadiene-3,5-dione

Abstract  The synthesis and crystal structure of 1,7-bis(4-chlorophenyl)-4-(1,3-dithiolan-2-ylidene)-1,6-heptadiene-3,5-dione is described. This compound is a curcuminoid analogue, configurationally symmetric about the C4–C5 atoms and also retains the two fold axis in the crystal phase. This compound crystallizes in the space group C2/c with unit cell parameters a = 19.203(1) ?, b = 13.147(1) ?, c = 8.801(1) ?, β = 112.99(1)°, with half a molecule in the asymmetric unit. The ketenedithioacetal functionality present between the carbonyl groups prevents the possibility of keto-enol tautomerization in this compound. The push-pull nature of the ketenedithioacetal functionality organizes the cinnamoyl groups parallel to each other. Index Abstract  The details regarding synthesis and crystal structure of the title compound which is a curcuminoid analogue is reported in this paper.      

Crystal Structure and Computational Study of 5-Ethyl-4-(4-Methoxyphenethyl)-4,5-Dihydro-3H-1,2,4-Triazol-3-One and 4-(4-Methoxyphenethyl)-5-Propyl-4,5-Dihydro-3H-1,2,4-Triazol-3-One

Crystallography Reports - Molecular structures of compounds 5-ethyl-4-(4-methoxyphenethyl)-4,5-dihydro-3H-1,2,4-triazol-3-one, (C13H17N3O2) (I) and...