Single crystal structure determination of cetylpyridiniumammonium bromide and Rietveld structure determination of cetylquinuclidinium bromide

The structures of cetylpyridiniumammonium bromide (CPyB) and cetylquinuclidinium bromide (CQB), two tetraalkylammonium bromide surfactants, are reported. In particular, whereas the structure solution of CPyB was carried out through conventional single-crystal diffractometry, the structure of CQB has been determined by means of powder diffractometry. CPyB crystallizes in P (1) over bar space group with cell parameters a = 7.618(2) Angstrom, b = 5.554(1) Angstrom, c = 27.474(7) Angstrom, alpha = 95.03(2)degrees, beta = 95.65(2)degrees, gamma = 100.89(2)degrees, V = 1129.2(5) Angstrom(3) (R = 0.066, wR = 0.054): CQB also in P (1) over bar with cell parameters a = 8.1395(8) Angstrom, b = 6.4475(7) Angstrom, c = 25.237(2) Angstrom, alpha = 99.921(6)degrees, beta = 93.123(9)degrees, gamma = 111.956(9)degrees, V = 1222.9(2) Angstrom(3) (R-p = 0.097, wR(p) = 0.128, R-exp = 0.078, and R(F-2) = 0.127).