Structural similarity in a series of alkali metal aluminates with heteroleptic tert-butoxide–isobutyl ligand sets

With the aim of increasing the number of well-defined alkali metal aluminates, six new crystalline examples containing heteroleptic tert-butoxide – isobutyl ligand sets are reported. NMR spectroscopic studies in C 6D 6 solution have determined their common general formula [(iBu) 2Al(OtBu) 2AM·(D)], where AM = Li, D = 2 THF, TMEDA or PMDETA; AM = Na, D = TMEDA or PMDETA; and AM = K, D = PMDETA. X-ray crystallographic studies show that despite the different sized alkali metals involved all six complexes adopt a common dinuclear motif with [AlO(AM)O] ring cores. Though Al–OtBu–Li linkages are common, the heavier alkali metal examples reported here are exceptionally rare. These structures could be interpreted as co-complexes between monomeric forms of tBuO(AM) and (iBu) 2Al(OtBu)