title: Amido-based potassium-alkaline earth metallates--synthesis and structures of heterobimetallic complexes of heavy s-block elements.
abstract: The metathesis reaction of potassium N-isopropylanilide with alkaline earth metal diiodides of calcium, strontium and barium in a molar ratio of 4:1 yields the corresponding alkaline earth metalates of the type [(THF)(n)K(μ-NPhiPr)(2)Ae(μ-NPhiPr)(2)K(THF)(n)] (1: Ae = Ca, n = 2). Stabilization and crystallization of such derivatives succeeds after exchange of the THF ligands by multidentate amino bases such as tetramethylethylenediamine (TMEDA) or pentamethyldiethylenetriamine (PMDETA). The influence of the size and hardness of the alkaline earth metal center on the molecular structures is studied with [(L)K(μ-NPhiPr)(2)Ae(μ-NPhiPr)(2)K(L)] (2: Ae = Ca, L = TMEDA; 3: Ae = Sr, L = TMEDA; 4: Ae = Sr, L = PMDETA; and 5: Ae = Ba, L = PMDETA). The molecular structures are dominated by (attractive and repulsive) electrostatic and steric factors leading to a shortening of the non-bonding AeK distances from calcium to barium.
authors: Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University, Humboldtstrasse 8, D-07743, Jena, Germany.
authors: Carsten
authors: C
authors: Glock
authors: Helmar
authors: H
authors: Görls
authors: Matthias
authors: M
authors: Westerhausen