In dilute aqueous solution, AlIII exists almost entirely as the octahedral Al(H2O)63+ ion at pH 7, while in the biochemically and geochemically critical pH range 4.3-7.0 other hydrolytic species such as AlOH(aq)2+exist that are traditionally assumed to be hexacoordinate. We show, however, from the kinetics of proton- and water exchange on aqueous AlIII, supported by Car-Parrinello simulations, that a five-coordinate Al(H2O)4OH2+ ion is important under ambient conditions. In water, AlIII differs strikingly from other trivalent metal ions.
Revised: May 19, 2011 |
Published: June 3, 2005
Citation
Swaddle T.W., J. Rosenquist, P. Yu, E.J. Bylaska, B.L. Phillips, and W.H. Casey. 2005.Kinetic Evidence for Five-Coordination in AlOH(aq)2+ Ion.Science 308, no. 5727:1450-1453.PNNL-SA-45039.