Well-defined vanadium organoazide complexes and their conversion to terminal vanadium imides: Structural snapshots and evidence for a nitrene capture mechanism

We report the synthesis and structural characterization of a family of well-defined organoazide complexes supported by a three-fold-symmetric pyrrolide scaffold and their conversion to the corresponding terminal imido congeners. Kinetic measurements on a series of structurally homologous but electronically distinct vanadium organoazide complexes reveal that the azido-to-imido transformations proceed via a process that is first-order in the metal complex and has a positive entropy of activation. Further studies suggest that these reactions may involve metal-mediated generation and capture of nitrene fragments.