Vanadyl(IV) Porphyrin Dimers with Palladium(II) and Platinum(II) Linkages: Syntheses, Electronic Properties, and Magnetic Interactions between the Two Moieties

We report the synthesis of new vanadyl porphyrins bearing peripheral coordination sites. By using palladium(II) or platinum(II) as connecting ions, porphyrin dimers were isolated and characterized by X-ray crystallography. These paramagnetic species were studied by electronic spectroscopy and continuous wave electron paramagnetic resonance (CW EPR). Large bathochromic shifts were observed by comparing porphyrin monomers and dimers showing that electronic delocalization was present as demonstrated earlier for diamagnetic compounds. Despite the large distance (>14 angstrom) between the two vanadyl centers in these dimers, small dipolar interactions between the two paramagnetic ions could be determined.

Automated summary

The synthesis of new vanadyl porphyrins with peripheral coordination sites is reported. Porphyrin dimers were isolated and characterized by X-ray crystallography using palladium(II) or platinum(II) as connecting ions. These paramagnetic species were studied by electronic spectroscopy and continuous wave electron paramagnetic resonance (CW EPR). Large bathochromic shifts were observed, indicating the presence of electronic delocalization as previously demonstrated for diamagnetic compounds. Despite the large distance (>14 angstrom) between the vanadyl centers in these dimers, small dipolar interactions between the two paramagnetic ions could be determined.