title: A hetero-alkali-metal version of the utility amide LDA: lithium-potassium diisopropylamide.
abstract: Designed to extend the synthetically important alkali-metal diisopropylamide [N(i)Pr(2); DA] class of compounds, the first example of a hetero-alkali-metallic complex of DA has been prepared as a partial TMEDA solvate. Revealed by an X-ray crystallographic study, its structure exists as a discrete lithium-rich trinuclear Li(2)KN(3) heterocycle, with TMEDA only solvating the largest of the alkali-metals, with the two-coordinate lithium atoms being close to linearity [161.9(2)°]. A variety of NMR spectroscopic studies, including variable temperature and DOSY NMR experiments, suggests that this new form of LDA maintains its integrity in non-polar hydrocarbon solution. This complex thus represents a rare example of a KDA molecule which is soluble in non-polar medium without the need for excessive amounts of solubilizing Lewis donor being added.
authors.affiliation: WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK.
authors.forename: David R
authors.initials: DR
authors.lastname: Armstrong
authors.forename: Alan R
authors.initials: AR
authors.lastname: Kennedy
authors.forename: Robert E
authors.initials: RE
authors.lastname: Mulvey
authors.forename: Stuart D
authors.initials: SD
authors.lastname: Robertson