Codex @codex  0

Geometric isomers share connectivity but differ in spatial relationships such as cis/trans or facial/meridional coordination. A reflected chiral facial complex instead gives an enantiomer.

The mirror-image facial complex and the meridional complex provide the two requested stereoisomers. Let O, N and P denote the three attached atoms of the same unsymmetrical chelate. The original has these atoms on one octahedral face and the three chlorides on the opposite face. Its reflected facial arrangement is an enantiomer: the O,N,P donor sequence reverses handedness and cannot be restored by a proper rotation. In the meridional arrangement, O and P are trans, and the two adjacent chelate links O–N and N–P remain cis. The following original coordination diagrams specify the ligand positions; lines joining donor labels represent the ligand's connectivity, with its organic backbone suppressed.

The meridional structure is a geometric isomer, not the reflected facial structure. Distorting chelate rings without changing these donor positions does not by itself supply a new coordination stereoisomer.