(5-Meth­oxy-1H-indol-3-yl)acetonitrile

In the title compound, C₁₁H₁₀N₂O, the O atom and the C atom of the methyl­ene group deviate only slightly [0.029 (3) and 0.055 (3) Å, respectively] from the approximately planar ring system (r.m.s. deviation = 0.013 Å). In the crystal, N—H...O hydrogen bonds link the mol­ecules into zigzag chains running along the b axis.

6-[(E)-2-Phenyl­vin­yl]-1H-indole

The title compound, C₁₆H₁₃N, is essentially planar [maximum deviation from the least-squares plane = 0.081 (3) Å], with a dihedral angle of 1.65 (13)° between the planes of the indole and benzene rings. In the crystal, there are no significant inter­molecular π–π inter­actions [minimum ring centroid–centroid separation = 4.217 (5) Å].

2-(7-Methyl-1H-indol-3-yl)acetonitrile

In the title compound, C₁₁H₁₀N₂, the carbonitrile group is twisted away from the indole plane [C_cy—C_me—C_ar—C_ar = 66.6 (2)°; cy = cyanide, me = methyl­ene and ar = aromatic]. In the crystal, N—H...N hydrogen bonds link the mol­ecules into C(7) chains propagating in the [001] direction.

2-(4-Meth­oxy-1H-indol-3-yl)acetonitrile

In the title compound, C₁₁H₁₀N₂O, the cyanide group is twisted away from the indole-ring plane [C_cy—C_me—C_ar—C_ar = 70.7 (2)°; cy = cyanide, me = methyl­ene, ar = aromatic], whereas the meth­oxy C atom is almost coplanar with the ring system [displacement = 0.014 (5) Å]. In the crystal, N—H...N hydrogen bonds link the mol­ecules into C(7) chains propagating in [100].

2-(6-Chloro-1H-indol-3-yl)acetonitrile

In the title compound, C₁₀H₇ClN₂, the carbonitrile group is twisted away from the plane of the indole ring system [C_cy—C_me—C_ar—C_ar = −44.7 (8)°; cy = cyanide, me = methyl­ene and ar = aromatic]. In the crystal, N—H...N hydrogen bonds link the mol­ecules into C(7) chains propagating in [010]. Aromatic π–π stacking inter­actions [minimum centroid–centroid separation = 3.663 (3) Å] are also observed.

5-Chloro-1H-indole-3-carb­oxy­lic acid

In the title compound, C₉H₆ClNO₂, the carboxyl group is twisted from the indole ring system by 9.00 (8)°. In the crystal, inversion dimers linked by pairs of O—H...O hydrogen bonds generate R₂²(8) loops and N—H...O hydrogen bonds link the dimers into (001) sheets. Aromatic π–π stacking inter­actions [centroid–centroid distance = 3.7185 (12) A °] are also observed.

5-Fluoro-1H-indole-3-carb­oxy­lic acid

In the title compound, C₉H₆FNO₂, the carboxyl group is twisted slightly away from the indole-ring plane [dihedral angle = 7.39 (10)°]. In the crystal, carboxyl inversion dimers linked by pairs of O—H...O hydrogen bonds generate R₂²(8) loops and N—H...O hydrogen bonds connect the dimers into (10) sheets.

6-Chloro­quinolin-2(1H)-one

In the title compound, C₉H₆ClNO, the Cl atom deviates by 0.142 (1) Å from the quinoline ring mean plane (r.m.s. deviation = 0.013 Å). In the crystal, N—H...O hydrogen bonds link the mol­ecules into [010] C(4) chains. Aromatic π–π stacking inter­actions [shortest centroid...centroid distance = 3.685 (3) Å] are also observed.

2-(4-Chloro-1H-indol-3-yl)acetonitrile

The title compound, C₁₀H₇ClN₂, contains two approximately planar mol­ecules, A and B (r.m.s. deviations = 0.039 and 0.064 Å, respectively) in the asymmetric unit. In the crystal, N—H...N hydrogen bonds link the mol­ecules into C(7) chains of alternating A and B mol­ecules propagating along the a-axis direction. The crystal used for the data collection was found to be a racemic twin.

4-Nitro­isophthalic acid

In the crystal structure of the title compound, C₈H₅NO₆, both carboxyl groups are involved in inter­molecular centrosymmetric cyclic O—H...O hydrogen-bonding associations, which give a zigzag chain structure extending along (21). Weak π–π stacking inter­actions are also present [minimum ring centroid separation = 3.893 (4) Å].

3-[(E)-2-Phenyl­ethen­yl]-1H-indole-6-carbonitrile

In the title compound, C₁₇H₁₂N₂, the inter­planar angle between the indole mean plane [max.deviation 0.030 (1) Å] and the phenyl ring is 24.32 (7)°. In the crystal, inter­molecular N—H...N[triple bond]C hydrogen bonds form zigzag chains in the a-axis direction augmented by weak C—H...N[triple bond]C contacts.

6-Fluoro-1H-indole-3-carb­oxy­lic acid

In the title compound, C₉H₆FNO₂, all the non-H atoms are approximately coplanar, the carb­oxy O atoms deviating by 0.0809 and −0.1279 Å from the indole plane. In the crystal, O—H...O hydrogen bonds link the mol­ecules into dimers which are linked via N—H...O hydrogen bonds and π–π inter­actions [centroid–centroid distance = 3.680 (2) Å]

Paliperidonium nitrate

In the title mol­ecular salt (systematic name: 3-{2-[4-(6-fluoro-1,2-benzoxazol-3-yl)piperidin-1-yl]eth­yl}-9-hy­droxy-2-methyl-1,6,7,8,9,9a-hexa­hydro­pyrido[1,2-a]pyrimidin-4-one nitrate), C₂₃H₂₉FN₄O₃⁺·NO₃⁻, the piperidine ring displays a chair conformation and its N atom is protonated; the N—H bond is in an axial orientation. The ring bearing the hy­droxy group exhibits a half-chair conformation. The hy­droxy group as well as the adjacent methyl­ene group are disordered over two sets of sites in a 0.823 (5):0.177 (5) ratio. In the crystal, O—H...N, O—H...O, N—H...O and N—H...N hydrogen bonds connect the components into a three-dimensional network.