THE VERSATILE CHEMISTRY OF ARENEMANGANESE CARBONYL-COMPLEXES

The manganese carbonyl fragment Mn(CO)(3)(+) is easily co-ordinated to a very wide range of aromatic molecules, e.g. benzenes, hydroquinones , naphthalenes, indoles and benzothiophenes. The resulting air-stable [Mn(eta(6)-arene)(CO)(3)](+) cations are quite electrophilic, and this is the basis for much interesting and useful chemistry. Carbon-donor nucleophiles ranging from weak to strong add rapidly and regioselectiv ely to the arene to afford thermally stable cyclohexadienyl complexes from which functionalized arenes and cyclohexadienes can be obtained a fter oxidative removal of the metal. Chemical reduction of [Mn(eta(6)- polyarene)(CO)(3)](+) with or without another metal complex present co nstitutes a general route to homo- and hetero-nuclear syn- and anti-fa cial bimetallic complexes with naphthalene-type ligands. Chemical redu ction of [Mn(arene)(CO)(3)](+) (arene = eta(6)-benzothiophene or eta(5 )-thiophene) leads to C-S bond cleavage and the formation of novel met allacyclic complexes of relevance to hydrodesulfurization chemistry. T hese and other aspects of arenemanganese carbonyl chemistry are discus sed.