The preparation of N-(p-ethylphenyl) thiobenzohydroxamic acid and its spectral properties are described in this paper. The preferred conformation of the acid is investigated by both infrared techniques and theoretical calculations at the DFT level. It is found that the acid exists in the cis thione (Z) form, rather than the trans form (E) in the gas phase. Both infrared spectroscopy and theoretical calculations show that this structure is stabilized by ...