A comparison of the crystal structures of some quaternary trimethylammonium salts related to dopamine and noradrenaline with those of the corresponding amines: a comment on their nicotine-like biological activities.

The crystal structures of seven substituted phenethylammonium salts and one (phenylpropyl)-ammonium salt have been determined. (I) Trimethyl(phenethyl)ammonium iodide, C11H18N+.I-, Mr = 291.2, orthorhombic, P2(1)2(1)2(1) (No. 19), a = 6.040 (2), b = 7.689 (2), c = 26.528 (9) A, V = 1232 (1) A3, Z = 4, Dx = 1.56 g cm-3, Mo K alpha radiation (lambda = 0.71073 A), mu = 25.33 cm-1, F(000) = 576, T = 298 K, R (wR) = 0.0302 (0.0305) for 1991 reflections with I greater than 3 sigma (I). (II) (p-Hydroxyphenethyl)trimethylammonium iodide, C11H18NO+.I-, Mr = 307.2, triclinic, P1 (No. 2), a = 9.619 (1), b = 9.926 (1), c = 14.179 (2) A, alpha = 95.24 (1), beta = 97.50 (1), gamma = 98.97 (1) degrees, V = 1317.2 (3) A3, Z = 4, Dx = 1.55 g cm-3, Mo K alpha radiation (lambda = 0.71073 A), mu = 23.79 cm-1, F(000) = 608, T = 298 K, R (wR) = 0.0351 (0.0373) for 4320 reflections with I greater than 3 sigma (I). (III) (m-Hydroxyphenethyl)trimethylammonium iodide hemihydrate, C11H18NO+.I-.1/2H2O, Mr = 316.2, monoclinic, P2(1)/n (non-standard, No. 14), a = 8.048 (2), b = 9.782 (3), c = 17.447 (7) A, beta = 90.15 (1) degrees, V = 1374 (2) A3, Z = 4, Dx = 1.53 g cm-3, Mo K alpha radiation (lambda = 0.71073 A), mu = 22.86 cm-1, F(000) = 628, T = 298 K, R (wR) = 0.0719 (0.0655) for 1006 reflections with I greater than 1 sigma (I).(ABSTRACT TRUNCATED AT 250 WORDS)