An intramolecular 1,5-chalcogen bond on the conformational preference of carbonyl thiocarbamate species

Two closely related carbamothioates were prepared by the reaction of benzoyl isothiocyanates and methanol. The crystal structures show the occurrence of 1,5-O⋯O intramolecular short distance that determines the conformational preference.

Dipole Moments of meta and para Substituted Benzoyl Isothiocyanates

For a series of meta and para substituted benzoyl isothiocyanates, the dipole moments were determined experimentally and calculated by vector addition of the bond and group dipole moments. Confirmation analysis revealed the preference of the synclinal conformation (τ ∀ 60°), which emerges from the rotation about the C(7)-N bond. MNDO calculations were also performed for the compounds, and the dipole moments obtained were compared with those from the above procedure.

A study of structure of meta and para substituted phenyl and benzoyl isothiocyanates by the MNDO method

On the basis of the optimized MNDO calculations of a selected series of meta and para substituted phenyl and benzoyl isothiocyanates it has been found that the –NCS group is non-linear in both the cases (the deviation from linearity is about 9°). For the phenyl isothiocyanates the values of CNC angles are in the region of 146.1° - 149.0°, and for the benzoyl isothiocyanates the respective regions for the CNC and OCN angles are 146.4° - 152.1° and 117.1° - 118.5°. In the meta substituted benzoyl isothiocyanates the –CONCS group is perpendicular to the phenyl residue. The results are discussed from the point of view of the electron distribution and dipole moments of the compounds studied.