First linear alignment of five C–Se...O...Se–C atoms in anthraquinone and 9-(methoxy)anthracene bearing phenylselanyl groups at 1,8-positions

Five Ci–Se...O...Se–Ci atoms in anthraquinone and 9-(methoxy)anthracene bearing phenylselanyl groups at 1,8-positions align linearly, the origin of which is shown to be a non-bonded 5c–6e interaction of the five atoms.