Structure of antischistosome compounds. V 1,6-Hexanediylbis(triphenylphosphonium) dibromide

C42H42P2(2+).2Br-, Mr = 768.6, triclinic, P1, a = 13.328 (2), b = 23.110 (3), c = 9.417 (1) A, alpha = 90.75 (1), beta = 109.62 (1), gamma = 91.23 (1) degrees, V = 2730.86 A3, Z = 3, Dx = 1.402 g cm3, graphite-monochromatized Cu K alpha radiation, lambda = 1.5418 A, mu = 52.0 cm-1, F(000) = 1182, T = 292 K. Final R = 0.051 for 5225 reflections with I greater than 3 sigma (I). Structure solved by Patterson methods and delta F syntheses. One molecule is located at the center of symmetry of the unit cell. The hexane moieties of all three molecules are in the trans extended conformation. However, one of the P-C-C-C torsion angles in the complete molecule in the asymmetric unit is 118.4 (6) degrees, the corresponding P-C-C-C torsion angle about the other P atom being 178.7 (5) degrees. This creates a conformational asymmetry in an otherwise symmetric molecule. This conformation permits the formation of a nearly square, planar, noncovalent interaction involving this P atom with one of the Br- ions and a symmetry-related Br--P interaction. The remaining P atoms and Br- ions are noncovalently linked to this square, approximately along the alpha axis. This noncovalent network is nearly parallel to the [011] plane, but does not extend beyond the [020] and [020] planes. The half-molecule in the asymmetric unit is approximately 45 degrees to the whole molecule, with two of its phenyl rings directed toward and perpendicular to one of the phenyl rings of the asymmetric triphenylphosphonium group of the whole molecule.(ABSTRACT TRUNCATED AT 250 WORDS)