Crystal structure of fluroxypyr

Abstract

In the title pyridine herbicide {systematic name: 2-[(4-amino-3,5-dichloro-6-fluoropyridin-2-yl)oxy]acetic acid}, C7H5Cl2FN2O3, the mean plane of the carboxylic acid substituent and the pyridyl ring plane subtend a dihedral angle of 77.5(1)°. In the crystal, pairs of O - H?O hydrogen bonds form inversion dimers with R 2 2(8) ring motifs. These are extended into chains along [011] by N - H?F hydrogen bonds. In addition, intermolecular N - H?O hydrogen bonds and weak π-π interactions [ring centroid separation = 3.4602(9)?] connect these chains into a three-dimensional network.