Abstract
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 At room temperature, the cyclopropane molecules, like those of the 6,5-annulene isomer and 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 and the low-temperature structure is not but rather a low-symmetry orthorhombic lattice in which The orientational melting takes place via a two-step transition centered around 198–213 K.
- Received 22 May 2000
DOI:https://doi.org/10.1103/PhysRevB.62.9305
©2000 American Physical Society