SULFUR-CONTAINING KEGGIN ANIONS AND CYCLIC POLYOXOTHIOANIONS

摘要

Large species containing transition metal and chalcogenide groups are involved in many areas of science and represent useful models for magnetochemistry studies, bio-inorganic chemistry, material science. Polyoxometalates, namely POMs, have applications in homogeneous and heterogeneous catalysis, and many studies are devoted to POMs since they are expected to mimic the reactivity of metal oxide surface and their catalytic properties. Conversely, alumina-supported molybdenum and tungsten sulfurs are industrially used in the hydrotreatement of crude oils (HDS) and in the activation of dihydrogen. Recent approaches of catalytic mechanisms consider Mo-S combinations as functional analogues of the active surface of MoS_2. A large number of thio- and oxothio-molybdates are reported in the literature, most of them being structurally based on mononuclear or oligomeric architectures like [MoO_(4-x)S_x]~(2-) (x= 1 to 4), [Mo_4O_4S_(14)]~(4-) or the cubane-like cluster [Mo_4S_4(CN)_(12)]~(5-) .