Metal Complexes with Tetrapyrrole Ligands, LXI. Structure and Products of Electrochemical Oxidation of Zirconium(IV) and Hafnium(IV) Bisporphyrinate Double‐Deckers

The electrochemical oxidation of zirconium and hafnium double‐deckers M(P) 2 (M=Zr, Hf; P=OEP, TPP) (Scheme 1) 2) leads to mono‐ and dications which show near infrared absorption bands which are of ≈ 2000 cm ‐1 higher energy than those of the corresponding cerium double‐decker cations. [Zr(OEP) 2 ]X, [Zr(OEP) 2 ]X 2 , and [Zr(TPP) 2 ]X (X=ClO 4 − and PF 6 − ) are isolated after electrochemical oxidation and are characterized by IR and NMR spectroscopy. Magnetic susceptibility measurements (2 K < T < 300 K) of the solids confirm the strong coupling of the electron spins in the diamagnetic dication salt [Zr(OEP) 2 ][ClO 4 ] 2 . The molecular structure of Zr(OEP) 2 is elucidated by an X‐ray structural analysis.