Effects of H and OH on HO as probed by the 1-propanol probing methodology: differential thermodynamic approach.

We applied what we call the "1-propanol (1P) probing methodology" on the effects of H and OH on liquid HO. We found that H is an amphiphile with a modest hydrophobic and an equally modest hydrophilic contribution. Its hydration number is 2 ± 1, suggesting that the equilibrium hydration structure is like the Zundel type (HO). OH, on the other hand, has a large hydration shell with 12 ± 3 HO molecules and acts as a hydrophobe-like hydration center. In other words, it forms a hydration shell around itself, but as the probing 1P increases and the available HO decreases, it exerts its influence over a longer range and reduces the hydrogen-bond probability of bulk HO away from hydration shells, just as a hydrophobe does to bulk HO.