Fig. 2. Hydration of the OH and NH2 substituents.
a Partial radial distribution functions gH-Ow(r) (solid line) and gO-Hw (r) (dashed line) of phenol hydroxyl group OH and water (orange). b gH-Ow(r) (solid line) and gN-Hw (r) (dashed line) of aniline’s amino group NH2 and water (blue); and c gH-Ow(r) (solid line) and gO-Hw (r) (dashed line) of p-nitrophenol hydroxyl group OH and water (green). Note that the amino group is a less strong hydrogen bonding donor than the OH group. d O-H···OW angle map for phenol; e N-H···OW angle map for aniline; and f O-H···OW angle map for p-nitrophenol, highlighting their role as hydrogen bonding donors. The sharp peak at ≈ 180° indicates that the hydrogen bonding is linear; g O···HW-OW angle map for phenol; h N···HW-OW angle map for aniline; and i O···HW-OW angle map for p-nitrophenol, highlighting their role as hydrogen bonding acceptors. j–l SDFs showing the 15% more likely position of water hydrogen (blue) and oxygen (orange) around the hydroxyl and amine groups. Note that the XH···X is linear in all three cases. Source data are provided as a Source Data file.