Parallels between the Chemistry of Calcium(II) and Ytterbium(II). Synthesis and Crystal Structure of a Calcium Alkoxo-Phosphide Cuboidal Complex

Metathesis between CaI 2 and K[P{CH(SiMe 3 ) 2 }(C 6 H 4 -2-OMe)] in THF yields the alkoxo-phosphide complex [Ca{P(CH[SiMe 3 ] 2 )(C 6 H 4 -2-O)}(THF)] 4 ·4THF ( 2 ) via a ligand cleavage reaction involving the migration of a methyl group from oxygen to phosphorus. X-ray crystallography shows that 2 contains a Ca 4 O 4 cuboidal core with μ 2 -phosphide groups bridging four of the faces of the cuboid.