Bridging ligands triple

One interesting complex has a deprotonated 1-n -2 cv-hydroxybenzylbenzimidazole ligand whose O atom forms an additional bridge to an oxo.368 The complex is unusual in having a double (rather than more common single or triple) bridge. Further, one of the MoVI atoms is five-coordinate while the other has the more conventional six-coordinate near-octahedral structure.368... 

Molybdenum(II) and molybdenum(III) form an extensive array of multiply bonded dimers, which contain Mo-Mo quadruple and triple bonds respectively. Much of the organometallic chemistry of this class of compound has come principally from the work of one research group. Homoleptic compounds suchas [Mo2Me8]" , [Mo() -allyl)4], which contains bridging and terminal allyl ligands (see Bridging Ligand), are readily synthesized from [Mo2(OAc)4]... 

Particularly interesting are the cases in which cyclic ligands can bridge metals resulting in triple-decker and higher-order sandwich compounds (Figure 5-19). 

A novel complex containing an arsenobenzene ligand Ph—As=As—Ph acting as a triple bridge between three Cr(CO)j fragments has been prepared from the reaction between [Cr2(CO),o] " and PhAsClj. The A -ray structure determination shows two Cr(CO)j groups co-ordinated to each As atom of the ligand and a third Cr(CO)j unit in -interaction with the As—As double bond as in (1). The heterocyclic compound... 

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