Structural investigation of the crystallized 2-nitropropane compound (C(3)H(7)NO(2)) was performed by X-ray powder diffraction at low temperature. A first crystalline phase, called phase alpha, is observed below 172 K. This form exhibits a triclinic symmetry with P-1 space group (a = 1.03.13(3) nm, b = 0.5873(2) nm, c = 1.6146(4) nm, alpha = 90.17(2)degrees, beta = 92.17(2)degrees and gamma = 90.09(2)degrees), and Z = 8). At T(t)= 172 K, a structural transition is observed which brings to another phase, called phase beta (above T(t)). This one contains four molecules per unit cell and shows a Pc2(1)n symmetry (a = 1.0141(3) nm, b = 0.5855(2) nm, and c = 0.8319(4) nm). In addition to the doubling of the c-axis, structural networks differ by the different conformations of NO(2) nitro groups and by the orientation of the propyl group in the unit cell. Both crystal structures can be described using infinite zigzag chains of C(3)H(7) NO(2) molecules showing a regular alternation along the c-axis. Two orientations of these ribbons, called A and B, are observed. The crystal structures are then built with different distribution of these ribbons within the crystalline network.