Isolation of Bridging and Terminal Coinage Metal–Nitrene Complexes

Transition
metal complexes featuring a metal–nitrogen multiple
bond have been widely studied due to their implication in dinitrogen
fixation and catalytic nitrogen–carbon bond formation. Terminal
copper– and silver–nitrene complexes have long been
proposed to be the key intermediates in aziridination and amination
reactions using azides as the nitrogen source. However, due to their
high reactivity, these species have eluded isolation and spectroscopic
characterization even at low temperatures. In this paper we report
that a stable phosphinonitrene reacts with coinage metal trifluoro­methane­sulfonates,
affording bridging and terminal copper– and silver–nitrene
complexes, which are characterized by NMR spectroscopy and single
crystal X-ray diffraction analysis.