The low-temperature crystal structure of RS-camphor

The crystal structure of the low-temperature phase of RS-camphor (1,7,7-trimethylbicyclo [2,2,1]heptan-2-one, C10H16O) has been solved at 100 K by high-resolution powder X-ray diffraction using synchrotron radiation. The structure is orthorhombic, space group Cmcm, with a = 6.8341(2) Angstrom, b = 11.6584(3) Angstrom, c = 11.5000(3) Angstrom, and Z = 4. The structure has four-fold disorder of the molecules, Left-handed and right-handed molecules are situated on the same crystallographic site, with an additional two-fold rotational disorder of the molecules, The structure was obtained from a combination of auto indexing, direct methods, and a grid search of molecular orientations. (C) 1997 Academic Press.