Poly-NHC Complexes of Transition Metals: Recent Applications and New Trends

The most significant recent developments in the chemistry of transition metal complexes with poly-N-heterocyclic carbene ligands (poly-NHCs) are reviewed herein. In particular, attention is focussed on the preparation of novel poly-NHCs, on their coordination chemistry towards transition metal centers as well as on the applications of the resulting complexes, which nowadays range from catalysis to photophysics and medicinal chemistry. The goal is to highlight the most important recent achievements in this complex field and to give to the reader an overview on the broad chemistry of these compounds.