The crystal structures of the isomorphous compounds 1,3-diammoniumpropyl dibromide and diiodide are reported. The structure was found to be: monoclinic, C42h − P2/n, Z = 4. The lattice constants of [H3N(CH2)3NH3]2+. 2Br− are a = 1343.8 pm, b = 457.9 pm, c = 1347.1 pm and β = 109.14°; those for [H3N(CH2)3NH3]2+. 2I− are a = 1421.3 pm, b = 478.0 pm, c = 1419.6 pm and β = 110.10°. The diammoniumpropyl cations are centrosymmetric and there are two formula units in the asymmetric unit. Hydrogen bonds NH ... X− (X = Br or I) were observed. The discrepancy in the 79Br and 127I NQR spectra which showed no isomorphism, is removed by reinvestigation of the 79,81Br NQR spectra. At 77 K, ν1 (79Br) = 24.432 MHz and ν2 (79Br) = 14.042 MHz. The structures and the NQR spectra are compared and discussed. © 1995, All rights reserved.
Dou, S. qi, Paulus, H., & Weiss, A. (1995). Crystal structure and halogen NQR of diammoniumalkane halides. Journal of Molecular Structure, 345, 1–10. https://doi.org/10.1016/0022-2860(94)08376-S