STRUCTURAL INVESTIGATION OF 1-AMINO-2,4,6-TRINITROBENZENES IN THE SOLID-STATE AND IN SOLUTION

The crystal structure of 1-pyrrolidino-2,4,6-trinitrobenzene 3, 1-morp holino-2,4,6-trinitrobenzene 4 and 1-piperidino-2,4,6-trinitrobenzene 5 have been determined by single-crystal X-ray diffraction data and th e structure in solution was investigated by UV-visible spectrophotomet ry and C-13 nmr. The three compounds are monoclinic, space group P2(1) /n. Unit cell dimensions are a = 6.660(1), b = 8.612(1), c = 20.696(3) Angstrom, beta = 90.73(1)degrees, and D-c = 1.58 g cm(-3) for compoun d 3; a = 7.090(2), b = 21.493(9), c = 8.298(3) Angstrom, beta = 101.27 (1)degrees, and D-c 1.60 g cm(-3) for compound 4 and a = 10.426(1), b = 10.038(1), c = 12.291(1) Angstrom, beta = 90.04(1)degrees with D-c = 1.53 g cm(-3) for compound 5 for Z = 4. In the solid state, differenc es regarding the planarity of the aromatic ring in the three substrate s were found. Rotation of the orthonitro groups and of the amino group out of the aromatic plane was observed both in the solid state and in the solution. Greater coplanarity of the two rings was found in 3 tha n in 4 and 5.