Cage Compounds of Heterotrimetallic Mixed Phosphanediide/Silanolate Aggregates with an Alkaline Earth Metal-Centered Phosphorus Octahedron
datasetposted on 05.12.2002, 00:00 by Matthias Westerhausen, Sabine Weinrich, Gernot Kramer, Holger Piotrowski
The lithiation of potassium triisopropylsilylphosphanide yields the corresponding phosphanediide. The subsequent metathesis reaction with SrI2 and BaI2 in the presence of hexamethyldisiloxane gives hexalithium hexapotassium strontium hexakis(triisopropylsilylphosphanediide)bis(trimethylsilanolate) (1) and the corresponding barium derivative (2), respectively. The alkaline earth metal atoms are surrounded octahedrally by the phosphanediide ligands. Six P3 faces of the octahedron are capped by the K atoms, and the P−P edges of two opposite P3 faces are bridged by the lithium atoms. The Li cations are also bonded to the Me3SiO substituents giving a coordination number of three for the alkali metals.