Balancing Conjugational Stabilization and Torsional Strain. The Solid-State Structure of a 2-Thioalkyl-Substituted Pyridine N-Oxide

The solid-state geometry of 2-(1-phenyl-4-penten-1-ylthio)pyridine N-oxide (2) (C₁₆H₁₇NOS) provides an insight into the spatial arrangement of the 2-thioalkyl side chain. The N2-C7-S8 bond angle [112.0 (2)°] shows a significant unprecedented distortion from the expected value of 120° towards the pyridine-N-oxide O atom. The substituents of the thioether are arranged to allow conjugational interaction of the lone pairs on sulfur and the heteroaromatic nucleus on one side and a minimization of conformational strain between the pyridyl and the alkenyl groups on the other side.

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