Arene-containing clusters

Sequences of proteins containing Rieske-type clusters have been deduced from the complete operons of several dioxygenases these dioxygenases require electrons from NAD(P)H to convert aromatic compounds to cis-arene diols. The water-soluble dioxygenase systems consist of a reductase and a terminal dioxygenase many dioxygenases also contain a [2Fe-2S] ferredoxin (20). The terminal oxygenases contain a Rieske-type cluster and the ferredoxins may contain either a Rieske-type or a 4-cysteine coordinated [2Fe-2S] cluster. 

More recently, the ruthenium-catalyzed hydrogenation of sorbic acid to cis-hex-3-enoic acid. Scheme 16, was achieved in a biphasic bmim-PF6-methyl tert- miy ether (MTBE) system. The ruthenium cluster [H4Ru(q -C6H6)4] [Bp4]4, in [bmim][BF4], was shown to be an effective catalyst for the hydrogenation of arenes to the corresponding cycloalkanes at 90 °C and 60 bar. The cycloalkane product formed a separate phase, which was decanted and the IL phase, containing the catalyst, could be repeatedly recycled. 

Heterometal alkoxide precursors, for ceramics, 12, 60-61 Heterometal chalcogenides, synthesis, 12, 62 Heterometal cubanes, as metal-organic precursor, 12, 39 Heterometallic alkenes, with platinum, 8, 639 Heterometallic alkynes, with platinum, models, 8, 650 Heterometallic clusters as heterogeneous catalyst precursors, 12, 767 in homogeneous catalysis, 12, 761 with Ni—M and Ni-C cr-bonded complexes, 8, 115 Heterometallic complexes with arene chromium carbonyls, 5, 259 bridged chromium isonitriles, 5, 274 with cyclopentadienyl hydride niobium moieties, 5, 72 with ruthenium—osmium, overview, 6, 1045—1116 with tungsten carbonyls, 5, 702 Heterometallic dimers, palladium complexes, 8, 210 Heterometallic iron-containing compounds cluster compounds, 6, 331 dinuclear compounds, 6, 319 overview, 6, 319-352... 

Kajiwara, T, Katagiri, K., Hasegawa, M., Ishii, A., Eerbinteanu, M., Takaishi, S. et al. (2006) Conformation-controlled luminescent properties of lanthanide clusters containing p-tert-butylsulfonylcalix[6]arene. Inorganic Chemistry, 45, 4880-4882. 

The Rieske dioxygenases (so-called because they contain a Rieske [2Fe—2S] cluster in addition to the mononuclear iron centre) catalyse cw-dihydroxylation of arene double bonds using NADH as the source of two electrons again, both dioxygen atoms are incorporated into the cA-diol product. 

Transition metal complexes of other relevant organonitrogen compounds such as isoquinoline, 5,6-benzoquinoline, 7,8-benzoquinoline, acridine, and phenanthridine are also known, and they contain theN-ligand coordinated in either the p fN) or the tl -arene fashion [49, 69, 70]. The triosmium cluster Os3(CO),o(CH3CN)2 reacts with polyaromatic N-heterocycles such as 5,6-benzoquinoline and phenanthridine in an analogous manner to Py and Q, yielding J.3, n (N,C,C) complexes [69]. 

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