Polyphosphorus compounds derived from P4 conversion with sterically demanding cobalt complexes

The conversion of P4 with [CpBnCo(CO)2] (CpBn = C5(CH2C6H5)5) under thermal conditions gives almost exclusively the P10 complex [(CpBnCo)4(μ4‐η4:η4:η2:η2:η1:η1‐P10)]. However, its reaction with [CpBnCo]n, under mild conditions afforded a mixture of products including the P8 species [(CpBnCo)3(μ3‐η4:η2:η2:η1:η1‐P8)] and a rare Co3 cluster [(CpBnCo)2Co(μ3‐η5:η2:η1:η1‐C40H33)(μ‐H)(μ3‐H)]. The products were studied in solution by multinuclear NMR spectroscopy and mass spectrometry and, for some compounds in the solid state, by single crystal X‐ray diffraction.