High-pressure polymorphism of cyclopentanol (C5H10O): the structure of cyclopentanol phase-V at 1.5 GPa.

The fully ordered high-pressure crystal structure of cyclopentanol (C5H10O) has been solved using single-crystal X-ray diffraction techniques on station 9.8 at the SRS Daresbury Laboratory. At pressures above 1.5 GPa, cyclopentanol crystallizes in the monoclinic P2(1)/c space group with a=17.882 (3), b=5.4573 (3), c=9.6817 (14) A, beta=104.699 (8) degrees and Z'=2. The crystal structure is characterized by the formation of hydrogen-bonded molecular chains, denoted C_2;2(4) in graph set notation, which lie parallel to the crystallographic c-axis, with the molecules adopting a pseudo fourfold arrangement around the central core of hydrogen bonds.