Term used by some authorities to refer to
stereoisomerism resulting from the arrangement of out-of-plane groups with respect to a plane
(
chiralityplane ). It is exemplified by the
atropisomerism of (
E)-cyclooctene (
chiral plane = double bond and attached atoms) or monosubstituted paracyclophane (
chiral plane = substituted ring). The configuration of molecular entities possessing planar
chirality is specified by the stereodescriptors

and

(or

and
).
Source:
PAC, 1996, 68, 2193
(Basic terminology of stereochemistry (IUPAC Recommendations 1996))
on page 2213