1,3,5-Tri-p-tolyl-pentane-1,5-diol

In the title compound, C₂₆H₃₀O₂, the central benzene ring forms dihedral angles of 14.85 (15) and 28.17 (14)° with the terminal benzene rings. The dihedral angle between the terminal benzene rings is 32.14 (13)°. The crystal packing exhibits two strong inter­molecular O—H⋯O hydrogen bonds, forming directed four-membered co-operative rings. A region of disordered electron density, most probably disordered ethyl acetate solvent mol­ecules, occupying voids of ca 519 ų for an electron count of 59, was treated using the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155]. Their formula mass and unit-cell characteristics were not taken into account during refinement. The structure was refined as an inversion twin [absolute structure parameter = −0.3 (4)].

1,5-Bis(4-chloro-phen-yl)-3-(4-methyl-phen-yl)pentane-1,5-dione

In the title mol­ecule, C₂₄H₂₀Cl₂O₂, the central methyl­benzene ring forms dihedral angles of 42.47 (10) and 34.34 (10)° with the terminal 4-chloro­phenyl fragments. The dihedral angle between the chloro­benzene rings is 34.45 (11)°. A weak intra­molecular C—H⋯O inter­action generates an S(6) ring motif. The crystal packing exhibits weak C—H⋯O hydrogen bonds and C—H⋯π inter­actions.

4-(2-Hydroxyphenyl)-3,5-dithiaheptanedioic acid

In the crystal of the title compound, C₁₁H₁₂O₅S₂, mol­ecules are linked by O—H⋯O hydrogen bonds and C—H⋯O inter­actions, forming a three-dimensional network.

(E)-3-(4-Meth-oxy-phen-yl)-3-[3-(4-meth-oxy-phen-yl)-1H-pyrazol-1-yl]prop-2-enal

In the title mol-ecule, C20H18N2O3, the pyrazole ring forms a dihedral angle of 2.2 (1)° with its meth-oxy-phenyl substituent and a dihedral angle of 67.2 (1)° with the benzene substituent on the propenal unit. In the crystal, mol-ecules are connected by weak C-H⋯O hydrogen bonds, forming R 2 (2)(26) and R 2 (2)(28) cyclic dimers that lie about crystallographic inversion centres. These dimers are further linked through C-H⋯O and C-H⋯N hydrogen bonds, forming C(8), C(9), C(10) and C(16) chain motifs. These primary motifs are further linked to form secondary C 2 (2)(15) chains and R 2 (2)(18) rings.

1-(2,4-Dinitro-phen-yl)-3-phenyl-4-phenyl-sulfanyl-1H-pyrazole

In the title mol­ecule, C₂₁H₁₄N₄O₄S, the pyrazole ring forms dihedral angles of 45.6 (1), 87.7 (1) and 27.4 (1)° with the phenyl, sulfur-substituted benzene and nitro-substituted benzene rings, respectively. In the crystal, mol­ecules are connected by weak C—H⋯O and C—H⋯N hydrogen bonds into layers parallel to (010).

5-(2-Nitro-1-phenyl-but-yl)-4-phenyl-1,2,3-selenadiazole

In the title compound, C(18)H(17)N(3)O(2)Se, the selenadiazole ring is planar [maximum deviation = 0.012 (2) Å for the ring C atom bearing the phenyl substituent]. The dihedral angle between the selenadiazole ring and the attached benzene ring is 46.5 (1)°. There is one short intra-molecular C-H⋯Se contact.

Ethyl 2-phenyl-3-(4-phenyl-1,2,3-selenadiazol-5-yl)-3-p-tolyl-propano-ate

In the title compound, C(26)H(24)N(2)O(2)Se, the selenadiazole ring is essentially planar [maximum deviation = 0.004 (3) Å]. The dihedral angle between the selenadiazole ring and the attached benzene ring is 50.17 (1)°. The crystal packing is stabilized by inter-molecular C-H⋯N inter-actions.

1-(2-Naphth-yl)-3-phenyl-3-(4,5,6,7-tetra-hydro-1,2,3-benzoselenadiazol-4-yl)propan-1-one

In the title compound, C(25)H(22)N(2)OSe, the fused six-membered cyclo-hexene ring of the 4,5,6,7-tetra-hydro-1,2,3-benzoselenadiazole group adopts a near half-chair conformation and the five-membered 1,2,3-selenadiazole ring is essentially planar (r.m.s. deviation = 0.004 Å). There are weak inter-molecular C-H⋯O and C-H⋯π inter-actions in the crystal structure. Inter-molecular π-π stacking is also observed between the naphthyl units, with a centroid-centroid distance of 3.529 (15) Å.

3-(4-Methyl-phen-yl)-1-phenyl-3-(4,5,6,7-tetra-hydro-1,2,3-benzoselenadiazol-4-yl)propan-1-one

In the title compound, C(22)H(22)N(2)OSe, the fused six-membered ring of the 4,5,6,7-tetra-hydro-benzo[d][1,2,3] selenadiazole group adopts a near to envelope (E form) conformation and the five-membered 1,2,3-selenadiazole ring is essentially planar (r.m.s. deviation = 0.0059 Å). In the crystal, adjacent mol-ecules are inter-linked through weak inter-molecular C-H⋯π inter-actions.

4-{(4-Chloro-phen-yl)[4-(4-methyl-phen-yl)-1,2,3-selenadiazol-5-yl]meth-yl}-4,5,6,7-tetra-hydro-1,2,3-benzoselenadiazole

In the title compound, C(22)H(19)ClN(4)Se(2), the mean plane of the non-fused selenadiazole ring forms dihedral angles of 54.20 (16)° and 70.48 (11)°, respectively, with the essentially planar [maximum deviations of 0.025 (5) and 0.009 (2) Å, respectively] methyl-phenyl and chloro-phenyl substituents. The tetra-hydro-1,2,3-benzoselenadiazole group is disordered over two sets of sites with a refined occupancy ratio of 0.802 (5):0.198 (5). In the crystal, weak inter-molecular C-H⋯N inter-actions are observed.

Spectral Analysis and Crystal Structures of 4-(4-Methylphenyl)-6-Phenyl-2,3,3a, 4-Tetrahydro-1H-Pyrido[3,2,1-jk]Carbazole and 4-(4-Methoxyphenyl)-6-Phenyl-2,3,3a, 4-Tetrahydro-1H-Pyrido[3,2,1-jk]Carbazole

The crystal structures of 4-(4-methylphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIa) and 4-(4-methoxyphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIb) were elucidated by single crystal X-ray diffraction. Compound (IIa), C₂₈H₂₅N, crystallizes in the triclinic system, space group P-1, with a = 8.936(2) Å, b = 10.490(1) Å, c = 11.801(1) Å, α = 102.69(5)^°,  β = 103.27(3)^°, γ = 93.80(1)^°, and Z = 2. The compound (IIb), C₂₈H₂₅NO, crystallizes in the monoclinic system, space group P2₁/a, with a = 11.376(5) Å, b = 14.139(3) Å, c = 13.237(4) Å, β = 97.41(3)^°, and Z = 4. In both the structures, the pyrido ring adopts a twist boat conformation and the carbazole molecule has the twisted envelope structure with C3 and C13 at the flap. No classical hydrogen bonds are observed in the crystal structures. Details of the preparation, structures, and spectroscopic properties of the new compounds are discussed.

(E)-3-(4-Chloro-phen-yl)-3-[3-(4-chloro-phen-yl)-1H-pyrazol-1-yl]prop-2-enal

In the title compound, C₁₈H₁₂Cl₂N₂O, the pyrazole ring is almost planar [r.m.s. deviation = 0.002 Å] while the two chloro­phenyl rings are twisted out from the plane of the pyrazole ring, making dihedral angles of 5.3 (1) and 65.34 (4)°. In the crystal, centrosymmetric R₂²(24) dimers are formed about crystallographic inversion centres through a pair of C—H⋯Cl inter­actions. These dimers are further linked through a C—H⋯O hydrogen bond, forming a C(8) chain extending along the a axis. C—H⋯π inter­actions are also observed.

(E)-3-Phenyl-3-(3-phenyl-1H-1-pyrazolyl)-2-propenal

In the title compound C₁₈H₁₄N₂O, the pendant rings make dihedral angles of 66.1 (1)° and 13.9 (1) with the central ring. In the crystal, two mol­ecules form a cyclic centrosymmetric R₂²(22) dimer through pairs of C—H⋯O bonds. These dimers are further connected into zigzag chains extending along the b axis through C—H⋯π and C—H⋯O inter­actions.

(E)-3-(4-Bromo-phen-yl)-3-[3-(4-bromo-phen-yl)-1H-pyrazol-1-yl]prop-2-enal

There are two crystallographically independent mol­ecules in the asymmetric unit of the title compound, C₁₈H₁₂Br₂N₂O. In each mol­ecule, one of the bromo­phenyl rings lies almost in the plane of pyrazole unit [dihedral angles of 5.8 (3)° in the first mol­ecule and and 5.1 (3)° in the second] while the other ring is approximately perpendicular to it [dihedral angles of 80.3 (3) and 76.5 (3)°]. The crystal packing shows inter­molecular C—H⋯O inter­actions. The crystal studied was a racemic twin.

3-(4-Chlorophenyl)-1-[(E)-1-(4-chlorophenyl)-2-(4-methylphenylsulfanyl)ethenyl]-4-(4-methylphenylsulfanyl)-1H-pyrazole

In the title compound, C₃₁H₂₄Cl₂N₂S₂, the pyrazole ring adopts planar conformation with a maximum deviation of 0.002 (2) Å. The chloro­phenyl rings are twisted out of the plane of the pyrazole ring by 75.1 (1) and 39.5 (1)°. The crystal packing is controlled by weak intermolecular C—H⋯π interactions.

(E)-3-(4-Methylphenyl)-3-[3-(4-methylphenyl)-1H-pyrazol-1-yl]-2-propenal

In the title compound, C₂₀H₁₈N₂O, the pyrazole ring adopts a planar conformation. The C—N bond lengths in the pyrazole ring are shorter than a standard C—N single bond (1.443 Å), but longer than a standard double bond (1.269 Å), indicating electron delocalization. The propenal group assumes an extended conformation. Inter­molecular C—H⋯O hydrogen bonds connect mol­ecules into cyclic centrosymmetric R₂²(26) dimers, which are cross-linked via C—H⋯π inter­actions.

4-(Cyclo-hexyl-sulfan-yl)-1-[(E)-2-(cyclo-hexyl-sulfan-yl)-1-phenyl-ethen-yl]-3-phenyl-1H-pyrazole

In the title compound, C₂₉H₃₄N₂S₂, the pyrazole ring is planar and both cyclo­hexane rings adopt chair conformations. The dihedral angles between the pyrazole ring and the two benzene rings are 59.9 (2) and 19.8 (2)°. The conformation and packing of the mol­ecules in the unit cell are stabilized by a weak intra­molecular C—H⋯S and C—H⋯N interactions, in addition to van der Waals forces.

1-[(E)-2-Formyl-1-(4-methylphenyl)ethenyl]-3-(4-methylphenyl)pyrazole-4-carbaldehyde

In the crystal structure of the title compound, C₂₁H₁₈N₂O₂, mol­ecules are linked through C—H⋯O inter­actions. Two symmetry-related mol­ecules form a cyclic centrosymmetric R₂²(20) dimer. These dimers are further connected into chains running along the b axis.

3-Cyclohexylsulfanyl-2-(4-methylphenyl)-5,7-dinitro-1H-indole

In the title compound, C₂₁H₂₁N₃O₄S, the cyclo­hexane ring adopts a chair conformation. The nitro and methyl­phenyl groups are all coplanar with the indole ring system. Intra­molecular N—H⋯O and C—H⋯S hydrogen bonds generate S(6) ring motifs. The mol­ecules form R₂²(20) centrosymmetric dimers via inter­molecular C—H⋯O hydrogen bonds. A short O⋯O contact [2.842 (2) Å] is observed in the dimer.

1-(2,4-Dinitro-phenyl)-3-(4-methyl-phenyl)-4-phenyl-sulfanyl-1H-pyrazole

In the title compound, C₂₂H₁₆N₄O₄S, the dihedral angles between the pyrazole ring and the pendant aromatic rings are 26.2 (1), 41.1 (1) and 89.5 (1)°. In the crystal structure, an intermolecular C—H⋯N bond helps to establish the packing. A short C⋯C contact of 3.110 (12) Å is observed between the C atom of the pyrazole CH group and one of the α-C atoms of the 4-methyl­phenyl ring.

4-(4-Chloro-phenyl-sulfan-yl)-1-[(E)-2-(4-chloro-phenyl-sulfan-yl)-1-phenyl-ethen-yl]-3-phenyl-1H-pyrazole

In the title compound, C₂₉H₂₀Cl₂N₂S₂, the pyrazole ring adopts a planar conformation. The chlorophenyl rings are twisted from the pyrazole ring at angles of 52.74 (14) and 29.92 (13)°, respectively. The crystal structure is stabilized by C—H⋯N and C—H⋯π inter­actions.

Diethyl 2-[(4-nitro-phen-yl)(4-phenyl-1,2,3-selenadiazol-5-yl)meth-yl]malonate

In the title compound, C(22)H(21)N(3)O(6)Se, the heterocyclic ring makes dihedral angles of 50.03 (11) and 67.75 (11)°, respectively, with the benzene and phenyl rings. The terminal C atoms of the ester groups are disordered over two positions: the site occupancies for the C atoms are 0.62 (3)/0.38 (3) and 0.48 (3)/0.52 (3). In the crystal structure, weak intra- and inter-molecular C-H⋯O inter-actions are observed.

4-(4-Chloro-phen-yl)-5-[1-(4-chloro-phenyl)-2-methyl-2-nitro-prop-yl]-1,2,3-selenadiazole

In the title compound, C₁₈H₁₅Cl₂N₃O₂Se, the selenadiazole ring makes dihedral angles of 49.87 (3) and 55.70 (3)° with the two benzene rings. The dihedral angle between the two benzene rings is 11.90 (5)°. In the crystal structure, intra­molecular C—H⋯O and C—H⋯Se inter­actions and inter­molecular C—H⋯O, C—H⋯Cl and C—H⋯N inter­actions are observed.

NMR investigation of hydrogen bonding and 1,3-tautomerism in 2-(2-hydroxy-5-substituted-aryl) benzimidazoles

The 1,3-tautomerism associated with 2-(2-hydroxy-5-substituted-aryl)benzimidazoles was studied in different solvents. The effect of hydrogen bonding involving the hydroxyl group of the 2-aryl ring on the tautomerism was investigated using NMR spectroscopy. The influence of the solvent concentration on 2-(2-hydroxy-5-chloroaryl)benzimidazole was studied in acetone-d6 and DMSO-d6.

Synthesis, characterization and antimicrobial studies of metal(II) bis-chelates and mixed-ligand complexes of alpha-(2-hydroxyphenyl)-N-(1-phenyl-2-nitroethyl)nitrone

This paper describes the synthesis of complexes of the type MB2. 2H2O and CuBL.2H2O where BH = alpha-(2-hydroxyphenyl)-N-(1-phenyl-2-nitroethyl)-nitrone, M = copper(II)/cobalt(II)/nickel(II) and LH = salicylaldehyde/salicylaldoxime/8-hydroxyquinoline/2-hydroxypyridine. The magnetic moment, ligand field spectra, thermal and ESR studies reveals that these dihydrates possess octahedral geometry. The antimicrobial studies of these complexes against several microorganisms such as Staphylococcus aureus, Escherichia coli, Klebsiella aerogenes, Salmonella typhi and Pseudomonas sp. have been tested and reported in comparison with ceftazidime standard.