Sulfenamides have been characterized by X-ray crystallography.  The S-N bond in sulfenamides is a chiral axis that leads to formation of diastereomeric compounds.  The existence of these distinct stereoisomers is due to the formation of a partial double bond between either sulfur or nitrogen’s lone pair and the other atom's antibonding orbitals.  Additionally bulky substituent groups and lone pair repulsion can contribute resistance to interconversion.  The resulting torsional barriers can be quite large and vary from 12-20 kcal/mol. The interactions are thought to be dependent on the torsional preferences (also known as the gauche effect). The nitrogen atom is usually pyramidal, but cyclic and strongly steric hindered acyclic sulfenamides can display a planar arrangement of bonds around the nitrogen atom.