Molecular compounds and complexes. VI. The crystal structure of 3/2 pyrene:picryl bromide

Abstract

Pyrene:picryl bromide, (Cx6H10)3/2:C6H2(NO2)3Br, is monoclinic with a=8.189 (2), b=21.070(6), c= 14.607 (4) A, fl= 91.7 (1) °, space group P21/c, Z= 4. Intensities of 2893 reflexions were measured on a Stoe Weissenberg diffractometer with graphite-monochromated Cu Kct radiation. The structure was solved by Patterson and Fourier methods and refined by block-diagonal least-squares calculations to a final R of 0-103. All the atoms have fairly large Debye-Waller factors, suggesting the occurrence of large in-plane librations and/or disorder. The crystal structure can be described in terms of mixed stacks along [001] and interstitial pyrene molecules whose centres lie at (0,0,-~-) and (0, 1⁄2, 0). The donor: acceptor arrangement within the stacks is similar to that in anthracene: 1,3,5-trinitrobenzene [Brown, Wallwork & Wilson (1964). Acta Cryst. 17, 168-176].