Alkali metal diphenylmethanides: Synthetic, computational and structural studies

In search of new synthetic precursors for the preparation of alkaline earth organometallic compounds, we investigated the application of a powerful desilylation reaction to cleanly afford a variety of contact and charge-separated alkali metal derivatives without the difficulties commonly encountered in other methods. The resulting diphenylmethanides display both contact molecules and separated ion pairs. Analysis of the structural data demonstrates that simple electrostatic models are insufficient for predieting and explaining the solid-state structures of these complexes. Detailed computational investigations were performed to probe the nature of the metal-anion and metal-donor interactions and determine the contributions of each to the observed solid-state structures.