Synthesis and characterization of monomeric Ba and Sr complexes with malonate and Lewis base ligands

Abstract The reaction of barium or strontium metal in ammonia gas-saturated THF with two equivalents of dimethyl malonate (dmalH) in the presence of tetraethylene glycol dimethyl ether (tetraglyme) or 1,1,4,7,7-pentamethyldiethylenetriamine (pmdt) yields Ba(dmal) 2 (tetraglyme) ( 1 ), Ba(dmal) 2 (pmdt) ( 2 ), Sr(dmal) 2 (tetraglyme) ( 3 ), and Sr(dmal) 2 (pmdt) ( 4 ) as colorless crystals in reasonable yields (45–52%). These complexes have been characterized by spectroscopic methods (IR and 1 H- and 13 C-NMR) and elemental analysis data. Molecular structures of 1 , 3 , and 4 have been determined by X-ray diffraction studies and have revealed that they are monomeric and the tetraglyme or pmdt ligand wraps around a central metal atom in a meridional plane with the dmal ligands on opposite sides of this plane.