2-[(1H-Benzimidazol-1-yl)meth­yl]phenol benzene hemisolvate

In the title solvate, C₁₄H₁₂N₂O·0.5C₆H₆, the complete benzene molecule is generated by a crystallographic inversion centre. The dihedral angle between the planes of the benzimidazole moiety and the phenol substituent is 75.28 (3)°. In the crystal, O—H...N hydrogen bonds link the mol­ecules into parallel chains propagating along [100]. The mol­ecules are further connected by C—H...π inter­actions.

6,6′-Dimethyl-2,2′-[imidazolidine-1,3-diyl­bis(methyl­ene)]diphenol

In the title compound, C₁₉H₂₄N₂O₂, a di-Mannich base derived from 2-methyl­phenol and 1,3,6,8-tetra­aza­tri­cyclo­[4.4.1.1^3,8]dodecane, the imidazolidine ring adopts a twist conformation, with a twist about the ring N—C bond [C—N—C—C torsion angle = −44.34 (14)°]. The two 2-hy­droxy-3-methyl­benzyl groups are located in trans positions with respect to the imidazolidine fragment. The structure displays two intra­molecular O—H...N hydrogen bonds, which each form an S(6) ring motif. In the crystal, the mol­ecules are linked by weak C—H...O inter­actions with a bifurcated acceptor, forming a three-dimensional network.

Redetermination of 1,3,6,8-tetra­aza­tri­cyclo­[4.4.1.1^3,8]dodeca­ne

The structure of the title compound, C₈H₁₆N₄, which consists of four fused seven-membered rings, has been redetermined at 173 K. This redetermination corrects the orientation of two H atoms, which were located at unrealistic positions in the original room-temperature study [Murray-Rust (1974). J. Chem. Soc. Perkin Trans. 2, pp. 1136-1141]. The complete mol­ecule is generated by -42m symmetry, with one quarter of a mol­ecule [one N atom (site symmetry m), two C atoms (one with site symmetry m and the other with site symmetry 2) and two H atoms] in the asymmetric unit. No directional inter­actions beyond van der Waals contacts are apparent in the crystal structure.

1,3-Bis(3-tert-butyl-2-hy­droxy-5-meth­oxy­benz­yl)hexa­hydro­pyrimidin-5-ol monohydrate

The asymmetric unit of the title compound, C₂₈H₄₂N₂O₅·H₂O, consists of one half of the organic mol­ecule and one half-mol­ecule of water, both of which are located on a mirror plane which passes through the central C atoms and the hydroxyl group of the heterocyclic system. The hydroxyl group at the central ring is disordered over two equally occupied positions. The six-membered ring adopts a chair conformation, and the 2-hy­droxy­benzyl substituents occupy the sterically preferred equatorial positions. The aromatic rings make dihedral angles of 75.57 (9)° with the mean plane of the heterocyclic ring. The dihedral angle between the two aromatic rings is 19.18 (10)°. The mol­ecular structure features two intra­molecular phenolic O—H...N hydrogen bonds with graph-set motif S(6). In the crystal, mol­ecules are connected via O—H...O hydrogen bonds into zigzag chains running along the a-axis direction.