4-Chloro-2′,4′,6′-triethylbenzophenone: a redetermination

The structure of the title compound [systematic name: (4-chlorophenyl)(2,4,6-trimethylphenyl)methanone], C19H21ClO, has been redetermined at 100 K. The redetermination is of significantly higher precision than the previous structure determination at 133 K and reveals disorder of the one of the o-ethyl groups [occupancy factors = 0.77 (1) and 0.23 (1)] that was not identified in the previous report [Takahashi & Ito (2010). CrystEngComm, 12, 1628–1634]. The C—C—C—C torsion angles of the major and minor disorder components of the ethyl group with respect to the attached benzene ring are 103.7 (2) and 172.0 (6)°, respectively. It is of interest that the title compound does not display a single-crystal-to-single-crystal polymorphic phase transition on cooling, as was observed for a closely related compound, a fact that can be attributed to the disorder in the ethyl group.