Abstract The complex [Rh(C 6 H 5 Me)P(OPh) 3 } 2 ]ClO 4 undergoes reactions which give rise to the replacement of the toluence by N- or P-donor ligands, diolefin or arenes and lead to cationic or neutral rhodium(I) complexes. The title compound is monoclinic P 1 /c with a = 14.9559(10), b = 10.1843(5), c = 26.6971(4) A. β = 92.49(1)° and Z = 4. The structure has been determined from three-dimensional