THE CRYSTAL-STRUCTURE AND DISORDER IN TETRAPROPYLAMMONIUM TETRAFLUOROBORATE, (N-C3H7)(4)NBF4

M-r = 273.164, orthorhombic, P2(1)2(1)2(1), a = 12.075(2) Angstrom, b = 13.694(2) Angstrom, c = 9.610(1) Angstrom, V = 1589(3) Angstrom(3), Z = 4, D-x = 1.141, D-m = 1.115 g cm(-3), lambda(MoKa) = 0.7107 Angstr om, mu = 0.91 cm(-1), F(000) = 592, R = 0.049 for 717 unique reflectio ns with I > 2 sigma(I). The interaction compound is formed by the tetr apropylammonium cation and the tetrafluoroborate anion. The remarkable features of this crystal at room temperature are: i) the non centrosy mmetric structure; ii) the ordered distribution of the fluoroborate te trahedra, also confirmed by NMR measurements, iii) the partial disorde r of the n-propylammonium cations, which are statistically arranged in two orientations symmetrical to a mirror plane.