Syntheses, structure, and Berry pseudorotation of ruthenium-, iron-, and cobalt-phosphorane complexes

Transition metal complexes bearing a phosphorane fragment with two 3-methylcatecholate substituents, Cp′(CO)2M{)2} (Cp′=η5-C5H5, η5-C5Me5; M=Ru, Fe) and L(CO)3Co{)2} (L=PPh3, PPh2Me), were prepared. The X-ray structure of (η5-C5Me5)(CO)2Ru{)2} was determined. From the variable-temperature 31P-NMR studies, the activation parameters for Berry pseudorotation around the pentacoordinate phosphorus were determined and discussed.