4-(Dec­yloxy)phenyl 2-oxo-7-trifluoro­methyl-2H-chromene-3-carboxyl­ate

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 R₂²(10) rings. The structure also features C—H...F and C—H...π inter­actions along [100] and [010], respectively.

4-(4-Methyl­phenyl­sulfon­yl)piperazin-1-ium tri­fluoro­acetate

In the title salt, C₁₁H₁₇N₂O₂S⁺·CF₃COO⁻, the cation is protonated at the secondary piperazine N atom. The dihedral angle between the benzene ring and the piperazine mean plane is 85.54 (10)°. In the crystal, cations and anions are connected by two types of strong N—H...O hydrogen bonds into chains extending along [101]. The chains are further assembled into (10-1) layers via stacking inter­actions between benzene rings of the cations [centroid–centroid distance = 3.7319 (13) Å] and a C—H...O inter­action involving a piperazine C—H group and a sulfonyl O atom. Another C—H...O inter­action between the piperazine ring and the sulfonyl group connects the ions into a three-dimensional network.

N′-Hy­droxy­pyridine-2-carboximidamide

The title mol­ecule, C₆H₇N₃O, is almost planar (r.m.s. deviation = 0.0068 Å) and adopts an E conformation about the C=N double bond. In the crystal, mol­ecules are linked by pairs of strong N—H...N hydrogen bonds, forming inversion dimers with R₂²(10) motifs. The dimers are further linked into C(3) chains through O—H...N hydrogen bonds.

6-Chloro-N-(pyridin-4-ylmeth­yl)pyridine-3-sulfonamide

In the title sulfonamide derivative, C₁₁H₁₀ClN₃O₂S, the dihedral angle between the pyridine rings is 46.85 (12)°. The N atom of the chloro­pyridine ring is anti to the N—H bond. In the crystal, mol­ecules are linked through N—H...N hydrogen bonds into zigzag chains parallel to [001] with a C(7) graph-set motif.