MOLECULAR AND CRYSTAL-STRUCTURE OF 1-(8-CARBOXYOCTYL)-1,3,5,7-TETRAAZAADAMANTAN-1-IUM BROMIDE AND 1-(6-BROMOHEXYL)-1,3,5,7-TETRAAZAADAMANTAN-1-IUM BROMIDE

The molecular and crystal structures of a pair of quarternised bromide derivatives of hexamethylenetetramine have been determined. 1-(8-Carb oxyoctyl)-1,3,5,7-tetraazaadamantan-1-ium bromide, 1, C14H27N4O2Br, M( r) = 363.31, triclinic, P (1) over bar, a = 9.759(5), b = 12.699(7), c = 14.125(6) Angstrom, alpha = 96.45(3), beta = 99.17(3), gamma = 104. 74(3)degrees, V = 1649.7(14) Angstrom(3), Z = 4, D-c = 1.463 g cm(-3), lambda(MoK alpha) = 0.7107 Angstrom, mu = 2.503 cm(-1), F(000) = 760, R (on F) = 0.058, R(W) (on I) = 0.162 for 3625 unique reflections wit h [I > 2 sigma(I)]. There are two symmetry independent sets of ions, e ach set being linked with strong O...Br interactions to form linear ar rays. The symmetry independent arrays are in turn connected with C-H.. .O interactions to form a layer. 1-(6-Bromohexyl)-1,3,5,7-tetraazaadam antan-1-ium bromide, 2, C12H29N4Br2, M(r) = 384.17, monoclinic, P2(1)/ n, a = 8.976(4), b = 15.743(8), c = 11.329(6) Angstrom, beta = 103.70( 2)degrees, V = 1555.3(13) Angstrom(3), Z = 4, D-c = 1.641 g cm(-3), la mbda(MoK alpha) = 0.7107 Angstrom, mu = 5.203 cm(-1), F(000) = 776, R (on F) = 0.066, R(W) (on I) = 0.168 for 1310 unique non-zero reflectio ns with [I > 2 sigma(I)]. Two Br- anions are located between two catio ns resulting in the formation of a cyclic centrosymmetric dimer. Each dimer is surrounded by six similar dimers and is connected to them wit h C-H...N hydrogen bonds to form corrugated molecular sheets. The symm etrical bond lengths of the hexamethylenetetramine skeleton are distor ted by quarternisation in both 1 and 2.