Ligand and induced internal redox processes in Mo- and W-S systems

Facets of early transition metal–sulfur chemistry: Metal–sulfur ligand redox, induced internal electron transfer, and the reactions of metal–sulfur complexes with alkynes

“…Interest in the reactions of tetrathiometalate anions, some of which have been known since the time of Berzelius, was stimulated by Mü ller's discovery of their synthetic potential and the unexpected ligand and metal-ligand redox processes of their derivatives [34]. The chemistry of binary and ternary Mo-and W-sulfides was then developed by Coucouvanis, Mü ller, Stiefel and others [61]. Stiefel later demonstrated that early transition metal thiometalates participated in a wide variety of induced internal electron transfer reactions with oxidants such as disulfides (of various thiols and 1,1-dithioacids) and dithietes.…”

“…Later, Pilato and coworkers discovered another route to Cp 2 Mo(dithiolene) complexes [128]. This was based on the reactions of Cp 2 Mo(SH) 2 (59) with a-bromo ketones (60), followed by deprotonation of initially formed (61), to give the dithiolene complexes (62) (Eq. (30)); a range of unsymmetrically substituted quinoxalinyl and pyridyl dithiolene complexes were produced in this fashion and several structures, including that of Cp 2 Mo{S 2 C 2 (2-quinoxalinyl)H}, were determined [128].…”

The Electronic Structure and Spectroscopy of Metallo‐Dithiolene Complexes

“…A considerable amount of experimental evidence over the last 40 years has pointed to the fact that dithiolenes are highly noninnocent ligands (20,86,110,113,(280)(281)(282). That is, they may be viewed in a valence bond description as existing somewhere between the extremes of neutral (dithione/dithiete) and dianionic (dithiolate) forms (Fig.…”

Oxidation führt zu Reduktion – redoxinduzierter Elektronentransfer (RIET)

“…RIET‐Reaktionen wurden bei mehreren Metallkomplexen mit S‐Liganden beschrieben, wobei sowohl eine zur Reduktion des Metallzentrums und Oxidation des S‐Liganden führende Oxidation als auch eine zur Oxidation des Metallzentrums und Reduktion des S‐Liganden führende Reduktion vorkommen kann 28. Anzumerken ist, dass sich diese Reaktionen von den oben beschriebenen Reaktionen mit 5 3+ – 10 3+ dahingehend unterscheiden, dass der RIET nunmehr das Endresultat einer chemischen Gesamtreaktionen ist, die zu weiteren Produkten führt.…”