organic compounds
In the title compound, C9H11NO2·C9H12NO2+·C6H2N3O7−, the phenylalanine cation forms a strong O—HO hydrogen bond with a phenylalanine zwitterion and is involved in a DL1 head-to-tail sequence. Each of the phenylalanine residues adopts a folded conformation. In the crystal structure, the hydrophobic double layers are aggregated about the y = 0 plane and sandwiched between hydrophilic layers about the y = plane.
organic compounds
In the title compound, C4H9N2O3+·C6H2N3O7−, the two ions are connected by strong asymmetric O—HO hydrogen bonds. The cation is involved in a Z1 (zigzag) head-to-tail sequence along the b axis. The torsion angle χ21 corresponds to a cis conformation. Hydrophobic layers across z = are sandwiched between hydrophilic layers across the z = 0 plane.
organic compounds
The asymmetric unit of the title compound, C6H13NO2·C6H14NO2+·C6H2N3O7-, contains two unprotonated leucine residues, two protonated leucinium cations and two picrate anions. The leucine residues show a class II hydrogen-bonding scheme and the leucinium residues show a class I hydrogen-bonding scheme. The leucine and leucinium residues form infinite hydrogen-bonded chains running along the a axis.
organic compounds
The title compound, C4H9N2O3+·NO3-, crystallizes with two asparaginium cations and two nitrate anions in the asymmetric unit. In both asparaginium residues, protonation take place at the carboxyl O atom cis to the amine group. Cation I exists in a trans conformation, whereas cation II exhibits a gauche I conformation. A straight head-to-tail sequence is observed for one of the asparaginium cations. The crystal structure is stabilized by inter- and intramolecular hydrogen bonding.
organic compounds
In the title complex, C6H6NO2+·H2PO4-, the nicotinium cations are sandwiched between layers of dihydrogenphosphate anions. The structure is held together by extensive hydrogen bonding between the O and N atoms of nicotinium cations and the O atoms of the phosphate anions, and between the O atoms of the phosphate anions themselves. The nicotinium cations are packed in layers, with an interlayer distance of 3.116 (5) Å.
organic compounds
The title compound, C6H6NO2+·C6H2N3O7-, is the picrate salt of the nicotinium cation. In the picrate anion, the ortho nitro groups are twisted out of the plane of the ring, whereas the para nitro group lies approximately in the ring plane. Hydrogen bonds from the nicotinate cation link two different picrate anions, forming a straight chain along the b axis. The picrate anions are stacked in columns along [010].