Ni(0) catalysed homo-coupling reactions: a novel route towards the synthesis of multinuclear ruthenium polypyridine complexes featuring made-to-order properties.

A new synthetic procedure for the efficient preparation of dinuclear ruthenium(II) polypyridyl complexes is reported. The compounds synthesised are [(bpy)2Ru(BPBT)Ru(bpy)2](PF6)2 and [(bpy)2Ru(BPZBT)Ru(bpy)2](PF6)2 (bpys2,29-bipyridine; H2BPBTs5,59- bis(pyridin-2-yl)-3,39-bis(1,2,4-triazole); H2BPZBTs5,59-bis(pyrazin-2-yl)-3,39-bis(1,2,4-triazole). Electrochemical experiments show that the two dinuclear systems investigated exhibit pH switchable intercomponent interactions

Artificial Photosynthesis for Solar Fuels - an Evolving Research Field within AMPEA, a Joint Programme of the European Energy Research Alliance

On the path to an energy transition away from fossil fuels to sustainable sources, the European Union is for the moment keeping pace with the objectives of the Strategic Energy Technology-Plan. For this trend to continue after 2020, scientific breakthroughs must be achieved. One main objective is to produce solar fuels from solar energy and water in direct processes to accomplish the efficient storage of solar energy in a chemical form. This is a grand scientific challenge. One important approach to achieve this goal is Artificial Photosynthesis. The European Energy Research Alliance has launched the Joint Programme "Advanced Materials & Processes for Energy Applications” (AMPEA) to foster the role of basic science in Future Emerging Technologies. European researchers in artificial photosynthesis recently met at an AMPEA organized workshop to define common research strategies and milestones for the future. Through this work artificial photosynthesis became the first energy research sub-field to be organised into what is designated "an Application” within AMPEA. The ambition is to drive and accelerate solar fuels research into a powerful European field - in a shorter time and with a broader scope than possible for individual or national initiatives. Within AMPEA the Application Artificial Photosynthesis is inclusive and intended to bring together all European scientists in relevant fields. The goal is to set up a thorough and systematic programme of directed research, which by 2020 will have advanced to a point where commercially viable artificial photosynthetic devices will be under development in partnership with industr

Verso la fotosintesi artificiale: competenze, strutture e progetti di ricerca nel settore

La fotosintesi artificiale, ovvero la conversione diretta di energia solare in energia chimica attraverso la sintesi fotoindotta di specie chimiche ad alta energia, quali idrogeno e altri combustibili, a partire da specie a bassa energia come acqua e anidride carbonica, un processo ispirato alla fotosintesi naturale, \ue8 stato per lungo tempo un sogno inseguito dalla comunit\ue0 scientifica internazionale. Gli sviluppi degli ultimi anni permettono adesso di affrontare il problema con buone speranze di successo. L\u2019articolo presenta una breve panoramica delle problematiche relative alla fotosintesi artificiale, delle strutture e dei progetti di ricerca nel settore attualmente presenti nei vari Paesi, con particolare attenzione per gli studi che vengono portati avanti dai ricercatori del SOLAR-CHEM, centro interuniversitario italiano per la conversione chimica dell\u2019energia solare

Tetrametallic molecular catalysts for photochemical water oxidation

Among molecular water oxidation catalysts (WOCs), those featuring a reactive set of four multi-redox transition metals can leverage an extraordinary interplay of electronic and structural properties. These are of particular interest, owing to their close structural, and possibly functional, relationship to the oxygen evolving complex of natural photosynthesis. In this review, special attention is given to two classes of tetrametallic molecular WOCs: (i) M4O4 cubane-type structures stabilized by simple organic ligands, and (ii) systems in which a tetranuclear metal core is stabilized by coordination of two polyoxometalate (POM) ligands. Recent work in this rapidly evolving field is reviewed, with particular emphasis on photocatalytic aspects. Special attention is given to studies addressing the mechanistic complexity of these systems, sometimes overlooked in the rush for oxygen evolving performance. The complementary role of molecular WOCs and their relationship with bulk oxides and heterogeneous catalysis are discusse

Absorption Spectra and Luminescence properties of Palladium(II) Terpyridine Complexes

The absorption and emission properties of [Pd(terpy)X]^+ \ (terpy=2,2^': 6,2^"-terpyridine,X=I,Cl,NO_2N_3) have been investigated. For comparison purposes, the same properties of the free terpy ligand have also been studied. The absorption spectra are almost solvent independent and quite similar for all the complexes studied, thus indicating that the most prominent bands are due to ligand-centred (LC) tansitions. The lowest energy band, however, is red-shifted with respect to that of the free terpy ligand by about 8100 cm^-^1, suggesting a strong distortion of the ligand structure on coordination to the metal atom. All the complexes exhibit a structured, long-lived (10^-^4-10^-^3_s) emission in butyronitrile at 77 K, with energy and bandshape quite similar to the long-lived (13ms) phosphorescence of the free terpy. The dependence of the emission lifetime on the nature of the X ligand is briefly discussed