Synthesis and characterization of dioxidodiphenylrhenium(VII) propionate

Treatment of propylperrhenate with 1 equiv. phenylzinc acetate yields dioxidodiphenylrhenium propionate. This novel complex can be synthesized with a yield of 41a% and is characterized by NMR and IR spectroscopy, as well as single-crystal X-ray diffraction. The compound is sensitive to moisture. It decomposes in sunlight and above 0 °C. The crystal structure has distorted octahedral symmetry around the rhenium center. Both rhenium-carbon bonds have a length of 2.141 Å and are significantly longer than other comparable rhenium-carbon bonds. The reaction of (μ-propionato)trioxidorhenium with phenylzinc acetate does not lead to the expected compound phenyltrioxidorhenium, but rather to the new complex dioxidodiphenylrhenium(VII) propionate. This compound is highly sensitive to air, moisture, and light, and it is stable only below 0 °C. It has been fully characterized by means of single-crystal X-ray diffraction and NMR spectroscopy.