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(CH3)(7-azain-2-Ph)(2)(7-azainH-2-Ph) (1), Al-3(mu(3)-O)(CH3)(3)(7-azain-2-Ph)(4) (2), and Al-3(mu(3)-O)(CH3)(3)(7-azain-2-CH3)(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-CH3 and 7-azain-2-Ph ligands. Variable-temperature 1D and low-temperature 2D EXSY H-1 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.