The planar <three-radialene> structure has a threefold axis normal to the plane, three in-plane twofold axes and the molecular plane as a horizontal mirror. Therefore its <molecular point group> is \b[$D_{3h}$], the <D3h molecular point group>. Its threefold connectivity does not supply a sixfold axis.

Solution

Past exam of the chemistry course of the year 3 of the natural sciences course of the University of Cambridge / 2022 / Paper 2B / Section A / 32 / d / Solution

 Solution (source code)