The aqueous chemistry of Al has a large impact across the biosphere, hydrosphere, geosphere, and anthrosphere. Despite a century of study, aqueous Al chemistry and speciation are still not well understood because of the challenges of selectively isolating and synthesizing specific Al-containing aqueous clusters and of precisely characterizing those clusters. We report the atom- and step-economical electrolytic synthesis of aqueous Al clusters combined with improved femtosecond Raman spectroscopy and computations to elucidate the structures and formation pathways of aqueous clusters in situ. We demonstrate the unique power of this integrated platform by synthesizing and characterizing flat [Al13(μ3-OH)6(μ2-OH)18(H2O)24]15+ clusters in water, which are versatile precursors for large-scale preparation of Al2O3 thin films and nanoparticles for electronics, catalysis, and corrosion prevention.
Wang, W.; Liu, W.; Chang, I-Y.; Wills, L.A.; Zakharov, L.N.; Boettcher, S.W.; Cheong, P.H.-Y.; Fang, C.; Keszler, D.A. Electrolytic synthesis of aqueous aluminum nanoclusters and in situ characterization by femtosecond Raman spectroscopy & computations, Proceedings of the National Academy of Sciences. PNAS November 12, 2013 vol. 110 no. 46 18397-18401