The crystal structure of anthranilic acid

Abstract

The crystal structure of the form of anthranilic acid stable at room temperature has been determined from three-dimensional X -ray diffraction data. 1416 structure amplitudes were used in refining the positional and anisotropic thermal parameters, resulting in a discrepancy index R = 7.0% , and e. s. d. of 0.0045 Å in the atomic coordinates. There are two non-equivalent molecules per lattice point in the space group P 2 1 cn , and the analysis shows these two molecules to have considerably different bond lengths. This evidence, taken together with the hydrogen-bonding system, indicates that one molecule is neutral, while the other is a zwitterion.