An X-ray determination of the structure of N-benzyl-o- methoxybenzothiohydroxamic acid (1a) shows the compound to have the Z-configuration with an intramolecular OH⋯S hydrogen bond [2.822(3) Å]. The nitrogen centre is planar, and the C-aryl group is orthogonal to the CNOH plane. 1H and 13C n.m.r. studies suggest that in non-polar solvents o-substituted N-benzylbenzothiohydroxamic acids retain the Z-configuration, whereas in polar solvents such as dimethyl sulphoxide or methanol the E-isomer is also present. The activation parameters for rotation about the aryl to (thio)carbonyl C-C single bond have been measured by a variable-temperature lineshape analysis of the 1H AB quartets due to the diastereoisotopic N-benzylic methylene protons. The results are compared with those of MNDO SCF-MO calculations.
|Number of pages||6|
|Journal||Journal of the Chemical Society, Perkin Transactions 2|
|Publication status||Published - 1 Jan 1984|