N,N,N′,N′-Tetramethylethylendiamine adducts of amido calcium bases - Synthesis of monomeric [(tmeda)Ca{N(SiMe3)2}2], [(tmeda)Ca{NiPr2}2], and dimeric Hauser base-type [(tmeda)Ca(tmp)(μ-I)]2 (tmp = 2,2,6,6-tetramethylpiperidide)

► A metathetical approach allows the synthesis of calcium-based superbases. ► Calcium-based Hauser bases undergo immediate ligand exchange yielding homoleptic derivatives. ► Structures of calcium bis(amides) are dominated by electrostatic and steric factors. ► In dimeric dialkylamido calcium iodide the smaller anion occupies the bridging position.