1-Hexyl-1,3,6,8-tetra­aza­tricyclo­[4.3.1.1^3,8]undecan-1-ium iodide

In the title compound, C₁₃H₂₇N₄⁺·I⁻, the ethyl­ene bridge is distorted from the ideal D_2d symmetry wherein an N—C—C—N planar bridge, around whose C—C bond the C—N and C—H bonds are exactly eclipsed, is disordered over two sites with equal occupancies. In both disorder components, the hexyl chain adopts an ideal all-trans conformation. In the crystal, adjacent ions are connected by C—H...I hydrogen bonds, forming ionic pairs that are further linked into chains along [101] via a second C—H...I inter­action.

Tris(2-carbamoylguanidinium) hydrogen fluoro­phospho­nate fluoro­phospho­nate monohydrate

The title structure, 3C₂H₇N₄O⁺·HFPO₃⁻·FPO₃²⁻·H₂O, contains three independent 2-carbamoylguanidinium cations, one fluoro­phospho­nate, one hydrogen fluoro­phospho­nate and one water mol­ecule. There are three different layers in the structure that are nearly perpendicular to the c axis. Each layer contains a cation and the layers differ by the respective presence of the water mol­ecule, the hydrogen fluoro­phospho­nate and fluoro­phospho­nate anions. N—H...O hydrogen bonds between the guanylurea mol­ecules that inter­connect the mol­ecules within each layer are strong. The layers are inter­connected by strong and weak O—H...O hydrogen bonds between the anions and water mol­ecules, respectively. Inter­estingly, the configuration of the layers is quite similar to that observed in 2-carbamoylguanidinium hydrogen fluoro­phospho­nate [Fábry et al. (2012). Acta Cryst. C68, o76–o83]. There is also present a N—H...F hydrogen bond in the structure which occurs quite rarely.

3,3′-(Ethane-1,2-di­yl)bis­(3,4-dihydro-2H-1,3-benzoxazine)

The title compound, C₁₈H₂₀N₂O₂, was prepared by Mannich-type reaction of phenol, ethane-1,2-diamine and formaldehyde. The heterocyclic rings adopt half-chair conformations. The acyclic methyl­ene groups attached to the N atoms are in an axial position. In the crystal, weak C—H...O hydrogen bonds link the mol­ecules into dimers. These dimers are further connected via C—H...π contacts.

2,2′-[Imidazolidine-1,3-diylbis(methyl­ene)]diphenol

In the title mol­ecule, C₁₇H₂₀N₂O₂, the imidazolidine ring adopts a twist conformation. The mean plane through the five atoms of the imidazolidine ring makes dihedral angles of 70.18 (4) and 74.14 (4)° with the planes of the two aromatic rings. The dihedral angle between the benzene rings is 53.11 (5)°. Both phenol –OH groups form intra­molecular hydrogen bonds to the N atoms, with graph-set motif S(6). In the crystal, pairs of O—H...O hydrogen bonds link the mol­ecules into dimers with R₄⁴(18) ring motifs. The crystal packing is further stabilized by C—H...O and weak C—H...π inter­actions.

6,6′-Di-tert-butyl-4,4′-dimeth­oxy-2,2′-[1,3-diazinane-1,3-diylbis(methyl­ene)]diphenol 0.19-hydrate

In the title hexa­hydro­pyrimidine derivative, C₂₈H₄₂N₂O₄·0.19H₂O, the 1,3-diazinane ring has a chair conformation with a diequatorial substitution. The asymmetric unit contains one half-organic mol­ecule and a solvent water mol­ecule with occupany 0.095. The mol­ecule lies on a mirror plane perpendicular to [010] which passes through the C atoms at the 2- and 5-positions of the heterocyclic system. The partially occupied water mol­ecule is also located on this mirror plane. The dihedral angle between the planes of the aromatic rings is 17.71 (3)°. Two intra­molecular O—H...N hydrogen bonds with graph-set motif S(6) are present. No remarkable inter­molecular contacts exist in the crystal structure.