Density functional theory studies on the external OH ^{?? ‐induced barrierless proton dissociation mechanism for the forced hydrolysis reaction of Al 3+3+ (aq)}

摘要

> The forced hydrolysis reaction of aqueous aluminum ion (Al 3+ ) is of critical importance in Al chemistry, but its microscopic mechanism has long been neglected. Herein, density functional calculations reveal an external OH ? ‐induced barrierless proton dissociation mechanism for the forced hydrolysis of Al 3+ (aq). Dynamic reaction pathway modeling results show that the barrierless deprotonations induced by the second‐ or third‐shell external OH ? proceed via the concerted proton transfer through H‐bond wires connected to the coordinated waters, and the inducing ability of the external OH ? decreases with increasing hydration layers between Al(H ₂ O) ₆ 3+ and the external OH ? . The OH ? ‐induced forced hydrolysis mechanism of Al 3+ (aq) is quite different from its self‐hydrolysis mechanism without OH ? . The inducing ability is a unique characteristic of OH ? , rather than other anions such as F ? or Cl ? .