Ruthenium-rhodium bimetallic catalysis

Ruthenium-Rhodium Bimetallic Catalysis. In seeking to inqprove the ethylene glycol syntheses of Table 1, one possibility that has not been extensively studied until recently (46-49), is the use of mixed metal centers with bimetallic, polymetallic or bridged-metal carbonyl clusters either as catalyst precursors, or generated in situ. 

Figure 1. Ethylene glycol from synthesis gas via ruthenium rhodium bimetallic melt catalysis. Effect of Rh Ru molar ratios. Synthesis conditions as per Table II. Effect of varying [Rh],0 effect of varying [Ru],...

Conventionally, organometallic chemistry and transition-metal catalysis are carried out under an inert gas atmosphere and the exclusion of moisture has been essential. In contrast, the catalytic actions of transition metals under ambient conditions of air and water have played a key role in various enzymatic reactions, which is in sharp contrast to most transition-metal-catalyzed reactions commonly used in the laboratory. Quasi-nature catalysis has now been developed using late transition metals in air and water, for instance copper-, palladium- and rhodium-catalyzed C-C bond formation, and ruthenium-catalyzed olefin isomerization, metathesis and C-H activation. Even a Grignard-type reaction could be realized in water using a bimetallic ruthenium-indium catalytic system [67]. 

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