Crystal structures of bis(quaternaryammonium bromide) surfactants, ethanediyl-1,2-bis(butyldimethylammonium bromide) dihydrate and propanediyl-1,3-bis(butyldimethylammonium bromide)

摘要

The crystal structures of two bis(quaternaryammonium bromide) surfacrants, CH3(CH2)(3)N+(CH3)(2)-(CH2)(ns)-N+(CH3)(2)(CH2)(3)CH3. 2Br(-) (n(s) = 2, 3), have been determined by single-crystal X-ray diffraction. The surfactant n(s) = 2 (dihydrate, C14N34N2Br2. 2H(2)O, M-r = 426.28) crystallizes in the monoclinic space group P2(1) with unit cell dimensions a = 8.1627(5), b = 8.1627(5), c = 12.5964(8) Angstrom and beta = 99.203(5)degrees. The crystal of surfactant n(s) = 3 (C15H36N2Br2, M-r = 404.27) has an orthorhombic space group Pbcn with unit cell dimensions a = 13.947(2), b = 16.924(1) and c = 17.145(2) Angstrom. The two n-butyl chains for n(s) = 2 are in the trans configuration with respect to the N-(CH2)(ns)-N skeleton, while those for n(s) = 3 are in the cis configuration. The (CH2)(3) segments of the two n-butyl chains are in the extended form, while the terminal methyl groups are disordered. (C) 1998 Elsevier Science B.V. All rights reserved. [References: 21]