Molybdocene Porphyrazines: A Peripheral Dithiolene Metallacycle Fused to a Porphyrinic Core

We have synthesized metallocene−porphyrazine (pz) complexes, as shown, and find them to be highly electroactive with five reversible redox couples. X-band EPR measurements of the (2H)−Mo(V) complex indicate that spin delocalization from the Mo(V) to the pz−dithiolene is significantly greater than for classical dithiolenes. Oxidation of the Cu(II)−Mo(IV) complex yields a system with two paramagnetic centers, Cu(II)−Mo(V), and this complex exhibits no EPR signal at 77 or 298 K, indicating remarkably strong antiferromagnetic coupling between spin centers (2J ≳ 200 cm-1).