Yann Gloaguen

Dinuclear Copper(I) Thiolate Complexes with a Bridging Noninnocent PNP Ligand

In natural systems, substrate activation and transformation is often achieved through metal–ligand cooperativity, and almost exclusively with earth-abundant 3d metals.[1] However, this concept of a metal and its ligand acting in concert is still strongly under-explored in synthetic chemistry with first-row transition metals, although for heavier analogues this has provided new routes to the formation and functionalization of useful building blocks.[2] Recently, a family of pincer ligands[3] was demonstrated to enable cooperative catalysis.[4] Strikingly, relatively little attention has been paid to the chemistry of Fe,[5] Co,[6, 7] and Ni[8–10] with these noninnocent ligand frameworks relative to the elegant reactivity detailed for their heavier congeners. Reports of the coinage metals Ag and Au are also scarce.[9c] Furthermore, Cu chemistry has rarely been explored with any pincer scaffold.[11]

Reactivity of a Mononuclear Iridium(I) Species Bearing a Terminal Phosphido Fragment Embedded in a Triphosphorus Ligand

The first example of an iridium(I) species bearing a terminal phosphido (PR(2)(-)) ligand is reported. This stable compound shows well-behaved reactivity toward various electrophiles, owing to its exposed phosphorus lone pair, allowing reversible protonation, selective alkylation, isolation of a phosphidoborane of iridium, and generation of a phosphido-bridged iridium(I)-gold(I) dinuclear species.

Electrocatalytic Azide Oxidation Mediated by a Rh(PNP) Pincer Complex

Abstract One‐electron oxidation of the rhodium(I) azido complex [Rh(N3)(PNP)] (5), bearing the neutral, pyridine‐based PNP ligand 2,6‐bis(di‐tert‐butylphosphinomethyl)pyridine, leads to instantaneous and selective formation of the mononuclear rhodium(I) dinitrogen complex [Rh(N2)(PNP)]+ (9 +). Interestingly, complex 5 also acts as a catalyst for electrochemical N3 − oxidation (E p≈−0.23 V vs. Fc+/0) in the presence of excess azide. This is of potential relevance for the design of azide‐based and direct ammonia fuel cells, expelling only harmless dinitrogen as an exhaust gas.