A homologous series of cobalt, rhodium, and iridium metalloradicals.

We herein present a series of d(7) trimethylphosphine complexes of group 9 metals that are chelated by the tripodal tetradentate tris(phosphino)silyl ligand [SiP(iPr)(3)]H ([SiP(iPr)(3)] = (2-iPr(2)PC(6)H(4))(3)Si(-)). Both electron paramagnetic resonance (EPR) simulations and density functional theory (DFT) calculations indicate largely metalloradical character. These complexes provide a rare opportunity to compare the properties between the low-valent metalloradicals of the second- and third-row transition metals with the corresponding first-row analogues.