The synthesis and crystal structure of 2-(chloroselanyl)pyridine 1-oxide: the first monomeric organoselenenyl chloride stabilized by an intramolecular secondary Se...O interaction

Abstract

The title compound, C5H4ClNOSe, is the product of the reaction of sulfuryl chloride and 2-selanyl-1-pyridine 1-oxide in dichloromethane. The molecule has an almost planar geometry (r.m.s. deviation = 0.012 Å), and its molecular structure is stabilized by an intramolecular secondary Se...O interaction of 2.353 (3) Å, closing a four-membered N—C—Se...O ring. The title compound represents the first monomeric organoselenenyl chloride stabilized intramolecularly by an interaction of this type. The non-valent attractive Se...O interaction results in a substantial distortion of the geometry of theipso-carbon atom. Theendo-cyclic N—C—Se [102.1 (3)°] andexo-cyclic C—C—Se [136.9 (3)°] bond angles deviate significantly from the ideal value of 120° for ansp2-hybridized carbon atom, the former bond angle being much smaller than the latter. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming zigzag chains propagating along [010]. The chains, which stack along thea-axis direction, are linked by offset π–π interactions [intercentroid distance = 3.960 (3) Å], forming corrugated sheets parallel to theabplane.