((CH2)6N4.CH2CHCH2)+Br- is an orthogonal ionic crystal. The crystal data are: Pmnb, a = 6.602(2)A, b = 12.184(4)A, c = 14.499(6)A, V = 1166A3, Mr = 261.2, Z = 4, Dc = 1.49Mgm*-3, F(000) = 536. The N(1) of HMT Directly bonds to the C(5) of (CH2CHCH2)+ with δ donoracceptor bond. The four C-N distances connected with N(1) are longer than the normal C-N single bond length. C(7) is disordered over two sites and both siteoccupation factors of C(7) and C(7)' are 0.5. The relation of the disorder structure with the molecular packing and the molecular conformation was discussed.

Key words: CRYSTAL STRUCTURE DETERMINATION, AMINES, METHYL GROUP, BROMOHYDROCARBON, PROPENE P