The rhodium(III) octaethylporphyrin complex Rh(OEP)(PPh3)Cl (1) has been synthesized via Rh(III) or Rh(I) precursors, and fully characterized both by spectroscopy and single crystal data. The crystals, available as a bis(chloroform) solvate are triclinic, P1, a = 13.478(5), b = 14.300(5), c = 15.346(4) Å, α = 102.33(2), β = 102.89(2), γ = 90.56(3)°, Z = 2, Dx = 1.384 g cm−3. The structure was determined from Mo diffractometer data and refined by least-squares methods to R = 0.095, Rw = 0.068 for 5189 reflections. The octahedrally coordinated rhodium atom is displaced by 0.077 Å from the mean plane of the four N atoms, towards the triphenylphosphine group. The average Rh – ring nitrogen distance is 2.024 Å, Rh—P is 2.306(3) Å and Rh—Cl, 2.442(2) Å. Solution equilibria studies on 1 describe formation of Rh(OEP)L2+ (L = PPh3, PnBu3) via thermal reactions (including thermodynamic data for the PPh3 system), and formation of Rh(OEP)Cl(L′) species (L′ = CO, THF, MeCN) via photochemical processes.