Catriona A. Morrison

42 salt forms of tyramine: structural comparison and the occurrence of hydrate formation.

The single-crystal diffraction structures of 38 salt forms of the base tyramine (4-hydroxyphenethylamine) are reported for the first time. Together with literature examples, these structures are discussed with respect to cation conformation, cation packing, hydrogen bonding and hydrate formation. It is found that isostructural cation packing can occur even with structurally different anions, with different hydration states and with different hydrogen bonding. Hydrate formation is found to be more likely both (i) when there is an increase in the total number of potential hydrogen bond acceptor and donor atoms; and (ii) when the ratio of potential hydrogen bond donor to acceptor atoms is low.

2,4,6-Trinitrophenyl benzoate

In the title mol-ecule, C13H7N3O8, the phenyl and benzene rings are rotated from the mean plane of the central ester group by 18.41 (9) and 81.80 (5)°, respectively. The dihedral angle between the rings is 80.12 (14)°. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions, forming helical chains along [010].

Supramolecular study, Hirshfeld analysis and theoretical study of 6-methoxyquinoline N-oxide dihydrate

In the crystal structure of 6-methoxyquinoline N-oxide dihydrate, C10H9NO2·2H2O, (I), the presence of two-dimensional water networks is analysed. The water molecules form unusual water channels, as well as two intersecting mutually perpendicular columns. In one of these channels, the O atom of the N-oxide group acts as a bridge between the water molecules. The other channel is formed exclusively by water molecules. Confirmation of the molecular packing was performed through the analysis of Hirshfeld surfaces, and (I) is compared with other similar isoquinoline systems. Calculations of bond lengths and angles by the Hartree-Fock method or by density functional theory B3LYP, both with 6-311++G(d,p) basis sets, are reported, together with the results of additional IR, UV-Vis and theoretical studies.

5,7,7,12,14,14-Hexamethyl-4,8-diaza-1,11-diazo-niocyclotetra-deca-4,11-diene diiodide dihydrate.

The asymmetric unit of the title compound, C16H34N4 2+·2I−·2H2O, contains one half-cation, one iodide anion and one water molecule. The cation has crystallographically imposed centrosymmetric symmetry. Despite some differences in the unit-cell dimensions, packing analysis on a cluster of 15 cations and a comparison of the hydrogen bonding suggests that this compound is isostructural with its bromide analogue. Intermolecular hydrogen bonding forms eight-membered [H—O—H⋯I]2 and [H—N—H⋯I]2 rings and creates a sheet structure.

Disodium (2rs, 3sr)-tartrate

The asymmetric unit of the anhydrous title compound, 2Na+·C4H4O6 2−, contains two sodium cations and one tartrate anion. Each sodium ion is six coordinate, with bonding to six O atoms from both the carboxylate and hydroxyl groups of the anion. A three-dimensional coordination network is formed with sodium ions stacking in layers along the c-axis direction. This network is supported by additional O—H⋯O hydrogen bonds.

(E)-Benzaldehyde O-{[3-(pyridin-3-yl)isoxazol-5-yl]meth-yl}oxime

The asymmetric unit of the title compound, C16H13N3O2, contains two independent molecules in which the pyridine and benzene rings form dihedral angles of 81.7 (2) and 79.8 (2)°, indicating the twist in the molecules. In the crystal, weak C—H⋯N interactions link molecules into chains along [100].

1-Benzylpiperidin-4-oneO-(2-bromobenzyl)oxime

In the title molecule, C19H21BrN2O, the piperidone ring adopts a chair conformation with a total puckering amplitude Q T of 0.554 (2) Å. The dihedral angle between the benzene rings is 64.10 (7)°. There are no significant intermolecular interactions.

1-Benzyl-piperidin-4-one O-(2-bromo-benz-yl)oxime.

In the title molecule, C19H21BrN2O, the piperidone ring adopts a chair conformation with a total puckering amplitude Q T of 0.554 (2) Å. The dihedral angle between the benzene rings is 64.10 (7)°. There are no significant intermolecular interactions.

1-Benzylpiperidin-4-one O-(2-bromobenzyl)oxime

In the title molecule, C19H21BrN2O, the piperidone ring adopts a chair conformation with a total puckering amplitude Q T of 0.554 (2) Å. The dihedral angle between the benzene rings is 64.10 (7)°. There are no significant intermolecular interactions.

(R,R)-Disynephrine ether bis­(hydrogen sulfate)

The asymmetric unit of the title compound [systematic name: (R,R)-2,4-bis(4-hydroxyphenyl)-N,N′-dimethyl-3-oxapentane-1,5-diammonium bis(hydrogen sulfate)], C18H26N2O3 2+·2HSO4 −, contains one half-cation and one hydrogen sulfate anion. The cation has crystallographically imposed twofold symmetry with the rotation axis passing through the central ether O atom. Hydrogen bonds between the hydroxy group and amine H atoms of the cation to two hydrogen sulfate anions link the three ions in a ring motif. A three-dimensional network is accomplished by additional O—H⋯O hydrogen bonds between the anions and by N—H⋯O hydrogen bonds between the cations. Disorder with equally occupied sites affects the H-atom position in the anion.