Structural insights into mono-amido tris-alkyl potassium aluminates

Co-complexation of a potassium amide with (Bu3Al)-Bu-i in the presence of the tridentate chelating ligand PMDETA results in a series of potassium aluminates of general formula [PMDETA center dot K(mu-amide)(mu-Bu-i)Al(Bu-i)(2)] [where amide = TMP (6); DMP (7); HMDS (8)] which have been characterized by solution NMR spectroscopy and X-ray crystallography. Their solid-state structures contain a central KNAlC ring whose degree of puckering is dictated by the differing interactions between the potassium centre and the aluminium bound anionic ligands.