Crystal structure of cis-benzocyclobutene-1,2-diol dinitrate

Abstract

Crystals of cis-benzocyclobutene-1,2-diol dinitrate, C₈H₆N₂O₆, are monoclinic, space group P2₁/n, a= 7·438(1)b= 15·733(2), c= 8·136(2)Å, β= 98·01(2)°, Z= 4. The structure was determined by direct methods, with Cu-K_α diffractometer data. Full-matrix least-squares refinement reduced R to 0·048 for 1110 observed data. The mean planes through the two rings make an angle of 4·3° and the four-membered ring is slightly puckered, the mean dihedral fold angle being 3·0°. Both nitrate groups are planar and make an angle of 78·6° with each other. There are differences in the valence angles at C(1) and C(2), which minimize intramolecular non-bonded repulsions.