The Crystal Structure of Acifluorfen {5-[2-Chloro-4-(trifluoromethyl)-phenoxy]-2-nitrobenzoic Acid}

Abstract

The crystal structure of the herbicide acifluorfen (5-[(2-chloro-4-trifluoromethyl)]phenoxy-2- nitrobenzoic acid] has been determined by X-ray diffraction and refined to a residual of 0.051for 1124 observed reflections. Crystals are monoclinic, space group C2/c with cell dimensions a 26.848(7), b 8 .O29(2), c 19 .Ol4(6) Å, ,R l34.72(2)º and Z 8. The molecules form centrosymmetric hydrogen-bonded cyclic dimers [O---0, 2.637(7) Å] with the carboxylic acid group and the phenoxy group synclinally related to the first phenyl ring while the nitro substituent isessentially coplanar with the ring.