Homogeneous hydrolysis of aluminum by decomposition of urea in solution was achieved because the urea coordinates to the Al3+ in solution, forming [Al(H2O)(5)(urea)](3+) and to a lesser extent [Al(H2O)(4)(urea)(2)](3+). Upon hydrolysis more hydrolyzed monomeric species, [Al(H2O)(5)(OH)](2+), [Al(H2O)(4)(OH)(2)](+), [Al(H2O)(4)(urea)(OH)](2+), and [Al(H2O)(3)(urea)(OH)(2)](+), were formed, followed by trimeric species and the Al-13 Keggin complex [AlO4Al12(OH)(24)(H2O)(12)](7+). The Al-27 NMR spectra indicated the formation of other complexes in addition to the Al-13 at the end of the hydrolysis reaction. (c) 2004 Elsevier Inc. All rights reserved.