ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 9, Number 3
JKCSEZ 9(3)
June 20, 1965 

The crystal structure of p-phenylenediamine dihydrochloride has been determined from X-ray oscillation and Weissenberg photographs. The crystal is triclinic, space group Ci1-P1-, with cell dimensions a = 4.38±0.02, b = 5.90±0.02, c = 8.76±0.03 Å, α = 110±1, β = 96±1 and γ = 101±1°. There is one molecule in the unit cell. The atomic coordinates were found by means of two-dimensional Fourier projection and (Fo-Fc) projection along the a, b and c axes. The structure of p-phenylenediamine dihydrochloride is discussed in relation to the structures of hexamethylenediamine dihydrochloride, hexamethylenediamine dihydroiodide and ethylenediamine dihydrochloride.