Molybdenum-ruthenium clusters

Nitride, ruthenium cluster complex, 26 287 Nitrido, ruthenium clusters, 26 286 Nitrogen, iridium(III) complex, 26 119 Nitrosyls, molybdenum, 26 132 tungsten, 26 133... 

C, Carbide iron complex, 26 246 ruthenium cluster complexes, 26 281-284 CHF,02, Acetic acid, trifluoro-tungsten complex, 26 222 CHFjOjS, Methanesulfonic acid, trifluoro-iridium, manganese, and rhenium complexes, 26 114, 115, 120 platinum complex, 26 126 CH2O2, Formic acid rhenium complex, 26 112 CH, Methyl iridium complex, 26 118 manganese complex, 26 156 rhenium complexes, 26 107 CHjO, Methanol platinum complexes, 26 135 tungsten complex, 26 45 CNajOuRusCn, Ruthenate(2- )ns-carbido-tetradecacarbonyl-disodium, 26 284 CO, Carbonyls chromium, 26 32, 34, 35 chromium, molybdenum, and tungsten, 26 343... 

On the (0001) face of a-alumina covered with one niobium, zirconium, molybdenum, ruthenium or palladium monolayer, Ohuchi and Koyama (1991) have shown that the metal d band is located in the energy range of the alumina gap. It is hybridized with the oxygen states of the valence band. In the series, more and more anti-bonding d states are filled, which yields results in agreement with the cluster calculations quoted above. 

Many carbonyl and carbonyl metallate complexes of the second and third row, in low oxidation states, are basic in nature and, for this reason, adequate intermediates for the formation of metal— metal bonds of a donor-acceptor nature. Furthermore, the structural similarity and isolobal relationship between the proton and group 11 cations has lead to the synthesis of a high number of cluster complexes with silver—metal bonds.1534"1535 Thus, silver(I) binds to ruthenium,15 1556 osmium,1557-1560 rhodium,1561,1562 iron,1563-1572 cobalt,1573 chromium, molybdenum, or tungsten,1574-1576 rhe-nium, niobium or tantalum, or nickel. Some examples are shown in Figure 17. 

One of the most important links between alkylidyne and alkyne compounds is that one of the first synthetic routes for cobalt al-kylidynes involved alkynes as reagents (264-268). In later studies, several other synthetic routes to cobalt (269-280), rhodium (281, 282), iron (283-285), molybdenum (286, 287), ruthenium (288-292), osmium (293, 294), nickel (295, 296), and some mixed-metal (165, 297-302) clusters have been developed. Reagents employed include carbynes (166, 277, 280), alkali metals (269), carbon disulfide (275), dithioesters (276, 282), RCC13, and acids (281, 282). 

Complexes of other transition metals have been reported to catalyze Pauson-Khand reactions. Buchwald reported intramolecular PKRs with 1.2 atm of CO at 90 °C in the presence of CpjTi(CO)2. " However, most other catalytic Pauson-Khand reactions have been conducted with late transition metal catalysts. Murai and Mitsudo simultaneously reported intramolecular PKRs catalyzed by ruthenium carbonyl clusters in dioxane or DMAc at 140-160 °C under 10-15 atm of CO. The first Rli-catalyzed PKR was reported by Narasaka. ° In this case, the reaction occurred with acceptable rates, even with CO pressures less than 1 atm. Shibata reported PKRs in refluxing xylenes under 1 atm of CO in the presence of catalytic amounts of PPli and [Ir(COD)Cl]2. Adrio and Carretero showed that the solvated molybdenum carbonyl complex Mo(DMF)3(CO)3 catalyzed intramolecular PKRs with monosubstituted olefins, as well as with disubstituted electron-poor olefins, and Hoye showed that W(CO)5(THF) catalyzes intramolecular PKRs. Iron and palladium complexes have also been reported to catalyze the PKR. 

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