A dimeric tethered pi-coordinated-phenoxy ruthenium precatalyst has been used for the base-free hydrogenation of CO2 in DMSO. The same precatalyst was also efficient in the reverse dehydrogenation of formic acid yet under base-free conditions. An unprecedented base-free cycle consisting in hydrogen storage and release was successfully implemented with the same precatalyst. The latent property of the catalyst has been introduced in the concept of hydrogen storage/transportation/release.

Diverse synthetic routes of tethered eta(5)-oxocyclo-hexadienyl ruthenium complexes, which are the extended version of the eta(4)-cyclopentadienone Shvo-type active catalyst, are described and their reactivity studies are reported. An original dimeric eta(5)-oxocyclohexadienyl compound has been isolated and its solid-state structure was established by X-ray analysis. DFT computational data suggested that this dimeric compound is prone to generate a coordinatively unsaturated mononuclear Lewis acid metal complex bearing a Lewis basic pi-coordinated eta(5)-oxocyclohexadienyl Iigand. Preliminary studies in (transfer)-hydrogenation of acetophenone confirmed that the dimeric eta(5)-oxocyclohexadienyl complex behaves as a bifunctional catalyst with metal-ligand cooperativity. Promising results were obtained under base-free conditions using dihydrogen, iPrOH, and formic acid as hydrogen highlighting the robustness and stability of the catalyst and opening perspectives donors, the latter being active in water, hence toward sustainable catalytic transformations.

A series of platinum(II) complexes bearing N-heterocyclic carbene NHC of the type [(NHC)PtX(L)] where L is a dithiocarbamate ligand and X iodide were prepared and fully characterized. The molecular structure of one derivative was determined by single-crystal X-ray analyses confirming that the dithiocarbamate is acting as a bidentate ligand to the metal. All complexes demonstrated potent in vitro antiproliferative activities against cancer cells. Mechanistic investigations revealed that mitochondrial dysfunction and ROS (Reactive Oxygen Species) production were correlated with the cytotoxic process induced by these complexes.