The energetics of isomerisation in Keggin-series aluminate cations

作者:Ohlin C Andre*; Rustad James R; Casey William H
来源:Dalton Transactions, 2014, 43(39): 14533-14536.
DOI:10.1039/c4dt01763c

摘要

Electronic-structure calculations show that the e-isomer of the polyoxoaluminate ion in the Keggin structure [AlO4-(Al(OH)(2)-(H2O))(12)](7+) is the thermodynamically favoured one. Direct interconversion between the epsilon- and delta-isomers via cap rotation has a prohibitively high energy barrier in vacuo, suggesting that isomerisation in solution either proceeds via a dissolution-precipitation pathway, or that solvation and/or coordination to counterions reduces the barrier significantly. The implications for the formation of the [Al2O8Al28(OH)(56)(H2O)26](18+) ion are discussed.

  • 出版日期2014-10-21