[Bis(2,4-dimethyl-6- tert .butyl-phenyl)ketone]chromium tricarbonyl—Stable torsional isomers

Complexation of bis(2,4-dimethyl-6-tert.butyl)ketone with chromium hexacarbonyl yields a mixture of two diastereomeric mono complexes in a ratio of 5 : 1. They can be separated by chromatography on silica gel at room temperature thus representing stable torsional isomers (isolable residual diastereomers).