Electrophilic Activation of Osmium-Nitrido Corroles: The OsN Triple Bond as a π-Acceptor Metallaligand in a Heterobimetallic OsVIN–PtII Complex

Abstract

Presented herein is a first investigation of the chemical reactivity of osmium-nitrido corroles, which are known for their unusual thermal, chemical, and photochemical stability. Elemental chlorine perchlorinates the β-positions of the triarylcorrole but leaves the OsN unit untouched. The OsN unit is also unaffected by a variety of other electrophilic and nucleophilic reagents. Upon photolysis, however, the anion of Zeise’s salt associates with the nitrido ligand to generate an Os^VI≡N—Pt^II complex. The very short OsN–Pt linkage [1.895(9)–1.917(8) Å] and the downfield ¹⁹⁵Pt NMR resonance (−2702 ppm) suggest that the OsN corrole acts as a π-accepting ligand toward the Pt(II) center. This finding represents a rare example of the successful photochemical activation of a metal–ligand multiple bond that is too kinetically inert to exhibit any appreciable reactivity under thermal conditions.