Direct Hydrogenation of Aluminum via Stabilization with Triethylenediamine: A Mechanochemical Approach to Synthesize the Triethylenediamine ⋅ AlH Adduct.

Two approaches for the synthesis of the triethylenediamine (TEDA) ⋅ AlH adduct have been discovered. Both, the mechanochemical procedure and the wet chemical method lead to crystalline products. Starting from metallic Al powder and TEDA, ball milling under a pressure of 100 bar H facilitates a direct hydrogenation of aluminum with conversions up to 90 %. Structure determination from X-ray powder diffraction data revealed an 1-D-coordination polymer of the type [TEDA-AlH ] . Furthermore, solid-state NMR techniques have been applied to analyze composition and structure of the products. Due to the polymeric arrangement, an enhanced stability of the material occurred which was investigated by thermal analysis showing a decomposition located above 200 °C. Overall, the stabilization of AlH by TEDA holds promise for hydrogen storage applications.