1,2,3,4,5,6,7,8-octahydroanthracene-9,10-dicarbonitrile at 172, 216, 256, and 297 K

Octahydroanthracenedicarbonitrile is monoclinic, space group P2(1)/c, at 17 2 K, a = 4.723(7), b = 8.254(3), c = 16.190(7) Angstrom, beta = 91.76(8)deg rees, Z = 2, V = 630.8(12) Angstrom(3). The molecule, located on a center o f symmetry, is disordered between the two senses of puckering in the alipha tic ring. The structure was also determined at 216, 256, and 297 K. The dis order increases with increasing temperature and can be described by a van't Hoff relationship with Delta H = 5.2(3) kJ mol(-1) and Delta S = 13.8(12)J K-1 mol(-1).