(R,R)-1-Acetyl-1'-(2,4,6-trinitro-phen-yl)-2,2'-bipyrrolidine.

The structure of the title mol-ecule, C16H19N5O7, is mainly determined by the steric effect of a bulky 2,4,6-trinitro-phenyl group attached to the N atom of a pyrrolidine ring. Both pyrrolidine rings adopt an envelope conformation, with one of the methylene C atoms as the flap in each case, and the N-C-C-N torsion angle along the bond connecting the two pyrrolidine rings is -174.9 (2)°. The benzene ring of the 2,3,5-trinitro-phenyl substituent is deformed and the r.m.s. deviation of its six atoms from the best plane is 0.026 Å. The N atoms of the two nitro groups in the ortho positions deviate from the best plane of the benzene ring by -0.033 (5) and 0.385 (5) Å. These groups, as well as the pyrrolidine ring, are twisted relative to the aromatic ring in the same direction, their best planes forming dihedral angles of 30.2 (2), 64.8 (1) and 46.6 (2)°, respectively, with the ring. An intra-molecular C-H⋯O hydrogen bond occurs. In the crystal, there is a short [O⋯C = 3.019 (4) Å] contact between a nitro O atom and a C atom of the benzene ring bearing the nitro group and a C-H⋯O inter-action between a methyl H atom and another nitro O atom.