A low-temperature polymorph of m-quinquephenyl

作者：Gomes Ligia R; Howie R Alan; Low John Nicolson^*; Rodrigues Ana S M C; Santos Luis M N B F

来源：Acta Crystallographica Section C-Structural Chemistry, 2012, 68: O492-U295.

DOI：10.1107/S0108270112046392

A low-temperature polymorph of 1,1%26apos;:3%26apos;,1 %26apos;%26apos;: 3 %26apos;%26apos;,1%26apos;%26apos;%26apos;: 3%26apos;%26apos;%26apos;,1%26apos;%26apos;%26apos;%26apos;-quinquephenyl (m-quinquephenyl), C30H22, crystallizes in the space group P2(1)/c with two molecules in the asymmetric unit. The crystal is a three-component nonmerohedral twin. A previously reported room-temperature polymorph [Rabideau, Sygula, Dhar %26 Fronczek (1993). Chem. Commun. pp. 17951797] also crystallizes with two molecules in the asymmetric unit in the space group P-1. The unit-cell volume for the low-temperature polymorph is 4120.5 (4) angstrom(3), almost twice that of the room-temperature polymorph which is 2102.3 (6) angstrom(3). The molecules in both structures adopt a U-shaped conformation with similar geometric parameters. The structural packing is similar in both compounds, with the molecules lying in layers which stack perpendicular to the longest unit-cell axis. The molecules pack alternately in the layers and in the stacked columns. In both polymorphs, the only interactions between the molecules which can stabilize the packing are very weak C-H center dot center dot center dot pi interactions.

• 出版日期2012-12