Ambient‐Condition nano‐Alumina Formation Through Molecular Control

Abstract

Abstract When toluene solutions of the tetrametallic compound, [Al{μ‐OEt) 2 AlMe 2 } 3 ] ( 1 ), are stirred in air at room temperature, pure amorphous nanoparticulate Al 2 O 3 precipitates. The average particle size is 17.7 ± 7.4 nm. The tetrametallic core of 1 , having the correct stoichiometry for alumina (2Al 2 O 3 ) appears to act as a template or nucleating site for the formation of alumina rather than the expected products of formula, AlOOH. The stability of the Al 4 O 6 core of 1 was tested by combining it with six equivalents of Ph 3 SiOH. This resulted in [Al{μ‐OEt) 2 Al(OSiPh 3 ) 2 } 3 ] ( 2 ). Upon exposure to air, compound 2 formed the hydroxide derivative [Al{μ‐OH) 2 Al(OSiPh 3 ) 2 } 3 ] ( 3 ). This demonstrates that the tetrametallic core of 1 is stable to both peripheral derivatization as well as alcoholysis of the internal bridging groups.