2-[(1H-Benzimidazol-1-yl)meth-yl]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.

A facile and efficient procedure for the synthesis of new benzimidazole-2-thione derivatives

A series of benzimidazole-2-thione derivatives was synthesized using a reaction between the macrocyclic aminal 16H,13H-5:12,7:14-dimethanedibenzo[d,i]-[1,3,6,8] tetraazecine (DMDBTA, 5) and various nucleophiles in the presence of carbon disulfide. A full chemical characterization using IR, ¹H-, ¹³C-NMR and GC-MS analyses of the new compounds is provided. These compounds were separated from the reaction mixture by column chromatography (CC) in highly pure form in 15%-51.4% yield.

2,9-Dichloro-6H,13H-5:12,7:14-dimethanodibenzo[d,i][1,3,6,8]tetraazecine

The title compound, C₁₆H₁₄Cl₂N₄, is isomorphous with 2,9-dimethyl-6H,13H-5:12,7:14-dimethano­dibenzo[d,i]-[1,3,6,8]tetra­azecine [Rivera et al. (2009 ▶). Acta Cryst. E65, o2553] and has twofold symmetry, with two carbon atoms located on a twofold axis. Only van der Waals forces occur between molecules in the crystal. In the isomorphous compound the crystal structure is stabilized by weak C—H⋯π inter­actions.

1,3-Bis(ethoxy-meth-yl)-1H-benzimidazole-2(3H)-thione

In the structure of the title compound, C₁₃H₁₈N₂O₂S, mol­ecules are linked together by inter­molecular C—H⋯S inter­actions into one-dimensional extended chains along the a axis. The crystal packing is further influenced by weak C—H⋯O inter­actions.

FT-IR and DFT studies of the proton affinity of small aminal cages

The proton affinity scale of small aminal cages was investigated using experimental and theoretical methodologies. The formation constant (K(f)) was determined for 1:1 hydrogen-bonded complexes between p-fluorophenol (PFP) and some aminal cage type (B) in CCl(4) at 298 K using FT-IR spectrometry. Then, the total interaction energy (E(PFF***B)), the energy of protonation (E(HB+)), the HOMO-LUMO GAP values and the Fukui index were calculated using the DFT/B3LYP/6-31 G(d,p) level of theory as theoretical descriptors. The values of the formation constant and energy changes vary with the tetrahedral character of the nitrogen lone pair. Good correlation between experimental and theoretical scales was observed, evidence for the existence of a relationship between the total energy of interaction calculated by structural parameters and the proton affinity in this series.