STRUCTURE OF THE GAMMA-1 PHASE OF ERUCIC-ACID

cis-13-Docosenoic acid, C22H42O2, M(r) = 338.57, triclinic, P1BAR, a = 5.462 (1), b = 5.197 (1), c = 44.16 (1) angstrom, alpha = 91.20 (1), beta = 90.85 (2), gamma = 117.32 (2)-degrees, V = 1113.0 (5) angstrom 3, Z = 2, D(x) = 1.01 g cm-3, lambda(Cu K-alpha) = 1.5418 angstrom, mu = 4.4 cm-1, F(000) = 380, T = 266 K, R(F) = 0.054, wR(F) = 0.074 for 2387 unique reflections with F > 3-sigma(F). Polymethylene segments form a triclinic subcell with parallel skeletal planes. The chains are inclined towards the interface of dimer layers by 42-degrees for the methyl-terminal chain and by 43-degrees for the carboxyl-terminal chain. The torsion angles of the C-C = C-C cis-olefin group are 98, 2, 95-degrees from the carboxyl side.