B. S. Palakshamurthy

4-[4-(Hept­yloxy)benzo­yloxy]phenyl 2-oxo-7-tri­fluoro­methyl-2H-chromene-3-carboxyl­ate

The title compound, C31H27F3O7, is a liquid crystal and exhibits enantiotropic SmA and nematic phase transitions. In the crystal, the the 2H-chromene ring system makes dihedral angles of 54.46 (17) and 7.79 (16)°, respectively, with the central benzene ring and 4-(heptyloxy)benzene ring. The three F atoms of the –CF3 group are disordered over two sets of sites, with an occupancy ratio of 0.62 (3):0.38 (3). The crystal structre features two pairs of C—H⋯O hydrogen bonds, which form inversion dimers and generate R 2 2(10) and R 2 2(30) ring patterns. C—H⋯O interactions along [100] and C—H⋯π interactions futher consolidate the packing, leading to a three-dimensional network.

4-(Oct­yloxy)phenyl 2-oxo-2H-chromene-3-carboxyl­ate

In the title compound, C24H26O5, the 2H-chromene ring system is essentially planar, with a maximum deviation of 0.029 (2) Å from the best-fit mean plane incorporating both rings. The dihedral angle between the 2H-chromene ring system and the benzene ring is 21.00 (1)°. In the crystal, pairs of C—H⋯O hydrogen bonds generate an R 2 2(8) ring pattern. These contacts are bolstered by weaker bifurcated C—H⋯O hydrogen bonds.

Methyl 4-benz­yloxy-2-hy­droxy­benzoate

In the title compound, C15H14O4, the dihedral angle between the benzene rings is 67.18 (8)°. The Ca—Cm—O—Ca (a = aromatic and m = methylene) torsion angle is 172.6 (3)° and an intramolecular O—H⋯O hydrogen bond generates an S(6) ring. In the crystal, molecules are linked by C—H⋯O hydrogen bonds into zigzag chains propagating in [001] and C—H⋯π interactions also occur.

4-Decyl-phenyl 4-benz-yloxy-3-methyl-benzoate.

In the title compound, C31H38O3, the central benzene ring makes dihedral angles of 66.06 (9) and 65.21 (8)°, respectively, with the benzyl and 4-decylphenyl rings.

Crystal structure of bis­(4-meth­oxy­phenyl) malonate

The complete molecule of the title compound, C17H16O6, is generated by crystallographic twofold symmetry, with the central methylene C atom lying on the rotation axis. The carbonyl O atom is disordered over two adjacent positions in a 0.63 (3):0.37 (3) ratio and the dihedral angle between the benzene rings in the two halves of the molecule is 79.31 (12)°. In the crystal, molecules are connected by C—H⋯O hydrogen bonds, generating (110) sheets. Very weak intrasheet C—H⋯π interactions are also observed.

Crystal structure of 4-bromo­phenyl-2-oxo-2H-chromene-3-carboxyl­ate

In the title compound, C16H9BrO4, the coumarin ring system is approximately planar, with an r.m.s deviation of the ten fitted non-H atoms of 0.031 Å, and forms a dihedral angle of 25.85 (10)° with the bromobenzene ring. The carbonyl atoms are syn. In the crystal, molecules are connected along [001] via C—H⋯O interactions, forming C(6) chains. Neighbouring C(6) chains are connected via several π–π interactions [range of centroid–centroid distances = 3.7254 (15)–3.7716 (16) Å], leading to sheets propagating in the bc plane.

tert-Butyl 2-{[5-(4-cyano-phen-yl)pyridin-3-yl]sulfon-yl}acetate.

In the title compound, C18H18N2O4S, the dihedral angle between the aromatic rings is 33.71 (9)° and an intramolecular C—H⋯O hydrogen bond closes an S(6) ring. In the crystal, molecules are linked by C—H⋯O and C—H⋯N hydrogen bonds to generate a three-dimensional network. A very weak aromatic π–π stacking interction is also observed [centroid–centroid separation = 3.9524 (10) Å].

6-(4-Fluoro-phen-yl)-3-phenyl-7H-1,2,4-tri-azolo[3,4-b][1,3,4]thia-diazine.

In the title compound, C16H11FN4S, the dihedral angles between the triazole ring and the phenyl and fluorobenzene rings are 23.22 (17) and 18.06 (17)°, respectively. The six-membered heterocyclic ring adopts a distorted envelope conformation, with the methylene C atom as the flap. In the crystal, the molecules are linked by two C—H⋯N and C—H⋯F interactions along [010], forming C(5), C(8) and C(13) chains repectively. C—H⋯π interactions involving the phenyl ring and π–π interactions [centroid–centroid separation for triazole rings = 3.5660 (18) Å] are also observed.

4-(Dec-yloxy)phenyl 2-oxo-7-trifluoro-methyl-2H-chromene-3-carboxyl-ate.

The title compound, C27H29F3O5, is a liquid crystal (LC) and exhibits enantiotropic SmA phase transitions. In the crystal, the dihedral angle between the 2H-chromene ring system and the benzene ring is 62.97 (2)°. The three F atoms of the –CF3 group are disordered over two sets of sites with occupancy factors 0.71 (4):0.29 (4). In the crystal, pairs of C—H⋯O hydrogen bonds form inversion dimers and generate R 2 2(10) rings. The structure also features C—H⋯F and C—H⋯π interactions along [100] and [010], respectively.

4-Nitro-phenyl 4-hy-droxy-3-methyl-benzoate.

The asymmetric unit of the title compound, C14H11NO5, contains two independent molecules in which the dihedral angles between the benzene rings are 89.27 (16) and 77.14 (12)°. In the crystal, molecules are linked by O—H⋯O hydrogen bonds, generating C(8) chains propagating in [010] for one molecule and [001] C(8) chains for the other. The chains are connected by C—H⋯O hydrogen bonds and π–π interactions [shortest centroid–centroid distance = 3.5908 (12)°], generating a three-dimensional network.