Conformational consequences of intramolecular hydrogen bonding by OH to the directional lone-pair of sulfur in derivatives of methyl phenyl sulfide, diphenyl sulfide, and diphenyl disulfide

Abstract

Complete spectral parameters for the 1H nmr spectra of 2-hydroxyphenyl methyl sulfide, 2, 2-hydroxyphenyl phenyl sulfide, 3, bis(2-hydroxy-3-tert-butyl-5-methylphenyl) sulfide, 4, and bis(2-hydroxyphenyl) disulfide, 5, are reported for CCl4 solutions at 305 K. For 2 the parameters are consistent only with a conformation in which the C—S—C plane is roughly perpendicular to the aromatic plane. The conformational determinant is the [Formula: see text] hydrogen bond which forces the mainly 3p orbital on sulfur into the benzene plane. In 3 a similar arrangement is found about the sulfur atom, with the phenyl group lying in the C—S—C plane and therefore perpendicular to the hydroxyphenyl plane (skew conformation). In 4 two [Formula: see text] hydrogen bonds exist, yielding a gable (twist) conformation. Compound 5 exists in the axial conformation with probable C2 symmetry, the CSSC dihedral angle and the CCSS torsion angles all being near 90°. For none of the compounds is there any evidence for [Formula: see text] interactions.