Highly Volatile Magnesium Complexes with the Aminodiboranate Anion, a New Chelating Borohydride. Synthesis and Characterization of Mg(H ₃BNMe₂BH₃)₂ and Related Compounds

Remarkably volatile magnesium complexes have been prepared with the modified borohydride ligand N,N-dimethylaminodiboranate, H₃BNMe ₂BH₃^-. The homoleptic complex Mg(H ₃BNMe₂BH₃)₂, its monoadducts with tetrahydrofuran and 1,2-dimethoxyethane, and the mixed ligand complex (C ₅Me₅)Mg(H₃BNMe₂BH₃)(thf) have been prepared. The homoleptic complex Mg(H₃BNMe ₂BH₃)₂ has a vapor pressure of 800 mTorr at 25 ̊C, which makes it the most volatile magnesium complex known. Crystal structures and NMR data are reported for all complexes. The compounds are potentially useful as chemical vapor deposition precursors to MgB₂ and MgO, and as hydrogen storage materials.