Herbicides. Part I. Crystal structure of 2,4-D (2,4-dichlorophenoxyacetic acid)

The crystal structure of 2,4-D has been determined by the symbolic addition procedure from 1 635 reflections collected by diffractometer. Crystals are triclinic, space group P with Z= 2 in a cell of dimensions: a= 913.1 (2), b= 782.7(2), c= 725.2(2) pm, α= 111.39(3)°, β= 105.79(3)°, and γ= 90.87(3)°. The structure was refined by least-squares to R 0.046. The two molecules are hydrogen bonded [263.2(6) pm] through their carboxylic acid groups to form a dimer about a centre of symmetry at ½,0,½.