1-Formyl-c-3,t-3-dimethyl-r-2,c-6-di-phenyl-piperidin-4-one

In the title compound, C(20)H(21)NO(2), the piperidine ring adopts a distorted boat conformation. The phenyl rings substituted at the 2- and 6-positions of the piperidine ring subtend angles of 86.0 (1) and 67.3 (1)° with the mean plane of the piperidine ring (all six non-H atoms). The crystal packing features C-H⋯O inter-actions.

2-(6-Methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)propanedinitrile

In the title compound, C₁₆H₁₃N₃, the cyclo­hexene ring adopts a sofa conformation. An intra­molecular N—H⋯N hydrogen bond generates an S(7) ring motif. In the crystal, the mol­ecules are linked by pairs of N—H⋯N inter­actions, forming centrosymmetric dimers with an R₂²(14) motif.

6-Bromo-2-(3-phenyl-allyl-idene)-2,3,4,9-tetra-hydro-1H-carbazol-1-one

Mol­ecules of the title compound, C₂₁H₁₆BrNO, are linked through pairs of N—H⋯O inter­molecular hydrogen bonds into centrosymmetric R₂²(10) dimers. One of the C atoms of the cyclohex-2-enone ring is disordered with refined occupancies of 0.61 (2) and 0.39 (2).

6-Bromo-2-[(E)-thio-phen-2-yl-methyl-idene]-2,3,4,9-tetra-hydro-1H-carbazol-1-one

In the title compound, C(17)H(12)BrNOS, the cyclo-hexene ring deviates only slightly from planarity (r.m.s. deviation for non-H atoms = 0.047 Å). In the crystal, the mol-ecules are linked into centro-symmetric R(2) (2)(10) dimers via pairs of N-H⋯O hydrogen bonds. The thio-phene ring is disordered over two positions rotated by 180° and with a site-occupation factor of 0.843 (4) for the major occupied site.

2-(6-Chloro-2,3,4,9-tetra-hydro-1H-carbazol-1-yl-idene)propane-dinitrile

The mol­ecular conformation of the title compound, C₁₅H₁₀ClN₃, is stabilized by an intra­molecular N—H⋯N hydrogen bond with an S(7) ring motif. The crystal packing is controlled by N—H⋯N and C—H⋯N inter­molecular inter­actions. One of the methyl­ene groups of the cyclo­hexene ring is disordered over two positions with refined occupancies of 0.457 (12) and 0.543 (12).

N′-[(E)-2-Chlorobenzylidene]-2-[(1,3,4-thiadiazol-2-yl)sulfanyl]acetohydrazide

In the title compound, C₁₁H₉ClN₄OS₂, the thia­diazole and chloro­phenyl rings are oriented at an angle of 43.1 (1)°. The sum of the bond angles around the amide N atom (359.8°) of the acetohydrazide group is in accordance with a model of sp² hybridization. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R₂²(8) loops. Weak C—H⋯π inter­actions also occur.

2-(1,2,3,4-Tetra-hydro-9H-carbazol-1-yl-idene)propane-dinitrile

In the title compound, C(15)H(11)N(3), the cyclo-hexene ring adopts a sofa conformation. An intra-molecular N-H⋯N hydrogen bond generates an S(7) ring motif. In the crystal, mol-ecules are linked by inter-molecular N-H⋯N, C-H⋯N and C-H⋯π inter-actions into a three-dimensional network.

2-Meth-oxy-quinoline-3-carbaldehyde

In the title compound, C(11)H(9)NO(2), the quinoline ring system is essentially planar (r.m.s. deviation = 0.005 Å) and the meth-oxy and aldehyde groups are almost coplanar with it [N-C-O-C = 6.24 (19) and O-C-C-C = 0.3 (2)°]. In the crystal, mol-ecules are linked by pairs of C-H⋯O hydrogen bonds, forming centrosymmetric R(2) (2)(10) dimers. The dimers are linked via π-π inter-actions involving the pyridine and benzene rings [centroid-centroid distance = 3.639 (1) Å].

8-Methoxy-3,3,5-trimethyl-3,11-dihydropyrano[3,2-a]carbazole

In the title compound, C₁₉H₁₉NO₂, commonly called koenimbine, the pyran ring adopts a sofa conformation. The carbazole ring system is planar [r.m.s. deviation = 0.063 (1) Å]. A C(10) zigzag chain running along the b axis is formed through inter­molecular C—H⋯O hydrogen bonds. The chains are linked via weak C—H⋯π and N—H⋯π inter­actions.

2-Amino-pyridinium picrate

In the title compound, C(5)H(7)N(2) (+)·C(6)H(2)N(3)O(7) (-), there are two crystallographically independent cations and anions (A and B) in the asymmetric unit. In both picrate anions, one of the nitro groups lies in the plane of the benzene ring [r.m.s. deviations = 0.014 (2) and 0.014 (2) Å for anions A and B, respectively] and the other two are twisted away by 39.0 (2) and 18.8 (2)° in A, and 18.2 (1) and 2.5 (2)° in B. In the crystal, the cations and anions are linked by inter-molecular N-H⋯O and C-H⋯O hydrogen bonds, forming a two-dimensional network.

Benzamide-picric acid (1/1)

In the title compound, C(7)H(7)NO·C(6)H(3)N(3)O(7), one of the nitro groups of the picric acid mol-ecule lies in the plane of the attached benzene ring [dihedral angle = 1.4 (1)°] while the other two are twisted away by 9.9 (1) and 30.3 (1)°. In the benzamide mol-ecule, the amide group is almost coplanar with the benzene ring [dihedral angle = 4.4 (1)°]. An intra-molecular O-H⋯O hydrogen bond generates an S6 ring motif. In the crystal, mol-ecules are linked into a ribbon-like structure along the b axis by O-H⋯O and N-H⋯O inter-molecular hydrogen bonds. In addition, C-H⋯O hydrogen bonds and short O⋯O contacts [2.828 (2) Å] are observed.

1-Formyl-t-3,t-5-dimethyl-r-2,c-6-diphenyl-piperidin-4-one

In the title compound, C₂₀H₂₁NO₂, the piperidine ring adopts a distorted boat conformation. The dihedral angle between the two phenyl rings is 61.33 (18)°. In the crystal, inter­molecular C—H⋯O inter­actions link the mol­ecules into zigzag C(5) chains running parallel to [100].

1-Chloro-acetyl-2,6-bis-(2-chloro-phen-yl)-3,5-dimethyl-piperidin-4-one oxime

In the title compound, C(21)H(21)Cl(3)N(2)O(2), the piperidine ring adopts a distorted boat conformation. One of the chloro-phenyl rings is almost perpendicular to the best plane through piperidine ring, making a dihedral angle of 88.7 (1)°, whereas the other ring is twisted by 71.8 (1)°. The crystal packing is stabilized by inter-molecular C-H⋯O, C-H⋯Cl and O-H⋯O inter-actions.

Ultrastructural evaluation of in vitro mineralized calcium phosphate phase on surface phosphorylated poly(hydroxy ethyl methacrylate-co-methyl methacrylate)

The in vitro functionality of surface phosphorylated poly(hydroxy ethyl methacrylate-co-methyl methacrylate), poly(HEMA-co-MMA) to induce bioinspired mineralization of calcium phosphate phase is evaluated. The primary nucleation of calcium phosphate on the surface phosphorylated copolymer occurs within 3 days of immersion when immersed in 1.5x simulated body fluid and the degree of mineralization is proportional to the hydroxy ethyl methacrylate content in the copolymer. The calcium phosphate phase is identified as hydroxyapatite by X-Ray diffraction analysis. The transmission electron microscopic evaluation combined with selected area diffraction pattern and energy dispersive analysis exemplified that the primary nuclei of amorphous calcium phosphate transforms to crystalline needle like calcium rich apatite, within a period of 3 days immersion in simulated body fluid. The atomic force microscopic results corroborate the c-axis growth of the crystals within 3 days immersion in SBF.

4-tert-Butyl-pyridinium picrate

In the title compound, C(9)H(14)N(+)·C(6)H(2)N(3)O(7) (-), the three nitro groups of the picrate anion are twisted out of the plane of the attached benzene ring; the dihedral angles are 32.8 (2), 10.5 (4) and 12.3 (4)°. The pyridinium cations and picrate anions are linked via bifurcated N-H⋯(O,O) hydrogen bonds. The ionic pairs are linked into a ribbon-like structure along [101] by C-H⋯O hydrogen bonds.

4-Amino-pyridinium picrate

In the title compound, C₅H₇N₂⁺·C₆H₂N₃O₇⁻, the 4-amino­pyridinium cation is essentially planar (r.m.s. deviation = 0.002 Å). The three nitro groups in the picrate anion are twisted away from the attached benzene ring [dihedral angles = 24.1 (1), 9.3 (3) and 21.4 (1)°]. In the crystal structure, the ions are linked into a three-dimensional network by N—H⋯O and C—H⋯O hydrogen bonds.

1-{[(Cyclo-hexyl-oxy)carbon-yl]-oxy}ethyl 3-{[2'-(2-ethyl-2H-tetra-zol-5-yl)biphenyl-4-yl]meth-yl}-2-oxo-2,3-dihydro-1H-benzimidazole-4-carboxyl-ate

In the title compound, C(33)H(34)N(6)O(6), the dihydro-benzimidazol-2-one ring system is essentially planar (r.m.s. deviation = 0.021 Å). The cyclo-hexane ring adopts a chair conformation. In the 5-(biphenyl-2-yl)-2H-tetra-zole fragment, the tetra-zole ring is twisted away from the attached benzene ring by 35.73 (11)° and the two benzene rings form a dihedral angle of 68.00 (9)°. An intra-molecular C-H⋯O inter-action is observed. In the crystal, the mol-ecules are linked into a zigzag chain running along the b axis by inter-molecular N-H⋯O hydrogen bonds.

4-Hydr-oxy-3-(1'-methyl-2-oxo-4'-phenyl-spiro-[indoline-3,2'-pyrrolidine]-3'-yl-carbon-yl)quinolin-2(1H)-one

In the title compound, C₂₈H₂₃N₃O₄, the dihedral angle between the quinoline and indole ring systems is 29.30 (5)°. The pyrrolidine ring adopts a twist conformation. An intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. A weak intra­molecular C3—H3⋯O3 inter­action is also observed. In the crystal, mol­ecules are linked by two sets of N—H⋯O hydrogen bonds, forming centrosymmetric dimers containing two R₂²(8) ring motifs. The dimers are linked via C—H⋯π inter­actions.