Highly Fluxional Blue Luminescent Aluminum Complexes: Al(CH3)(7-azain-2-Ph)2(7-azainH-2-Ph), Al3(μ3-O)(CH3)3(7-azain-2-Ph)4, and Al3(μ3-O)(CH3)3(7-azain-2-CH3)4 (7-azain = 7-Azaindole Anion)

The new aluminum complexes Al(CH 3 )(7-azain-2-Ph) 2 (7-azainH-2-Ph) ( 1 ), Al 3 (μ 3 -O)(CH 3 ) 3 (7-azain-2-Ph) 4 ( 2 ), and Al 3 (μ 3 -O)(CH 3 ) 3 (7-azain-2-CH 3 ) 4 ( 3 ), where 7-azain = 7-azaindole anion, have been synthesized and characterized structurally. The three aluminum atoms in compounds 2 and 3 are bridged by an oxo ligand. Compounds 2 and 3 have an asymmetric structure in the solid state that results in a distinct chemical environment for each aluminum atom and each 7-azain-2-R ligand in the compounds. All compounds emit a blue color, when irradiated by UV light. The blue emission is attributed to the coordinated 7-azain-2-CH 3 and 7-azain-2-Ph ligands. Variable-temperature 1D and low-temperature 2D EXSY 1 H NMR experiments established that compounds 2 and 3 are highly fluxional in solution, attributable to an unusual intramolecular migration of the coordinated 7-azain-2-R ligands.