A combination of X-ray single-crystal diffraction and Monte Carlo structure solution from X-ray powder diffraction data in a structural investigation of 5-bromonicotinic acid and solvates thereof

The crystal structures of 5-bromonicotinic acid ethylacetate 1, 5-bromonicotinic acid acetonitrile 2, and 5-bromonicotinic acid methanol 3 (all of which were obtained from single-crystal data) and of 5-bromonicotinic acid 4 (solved from powder diffraction data using a direct-space method based on the Monte Carlo technique) are presented; in 1-3, heteromeric N-H...O/C-H...O hydrogen-bonds lead to infinite polar chains of 5-bromonicotinic acid, whereas in 4, the principal noncovalent connector (head-to-head acid...acid hydrogen bonds) generates centrosymmetric dimers.