M. R. Stetzer, P. A. Heiney, P. W. Stephens, R. E. Dinnebier, Q. Zhu, A. R. McGhie, R. M. Strongin, B. Brandt, A. B. Smith, III, Phys. Rev. B 62, 9305-9316 (2000)
We have used x-ray powder diffraction and differential scanning calorimetry to study the crystalline structures and thermal behavior of the 6,6-cyclopropane isomer of C61H2. At room temperature, the C61H2 cyclopropane molecules, like those of the 6,5-annulene isomer and C60O epoxide, are orientationally disordered and crystallize on a face-centered cubic lattice such that their methylene groups are statistically disordered among the octahedral voids. Unlike 6,5-C61H2 and C60O, the low temperature structure is not Pa-3bar, but rather a low-symmetry orthorhombic lattice in which a is approximately equal to b , which is less than c. The orientational melting takes place via a two-step transition centered around 198-213 K.
GO TO PAUL HEINEY'S PERSONAL WEB PAGE