Molybdenum tricarbonyls determination

Few examples have been reported of metals coordinated to six-membered boron-sulfur heterocycles. Ashe et al. prepared 4-methyl-l,4-thiaborin (SC4H4BMe) which forms a stable molybdenum tricarbonyl sandwich complex 144.158 jn g etjert s laboratory, the reaction of the diborolyl complex 33 (Section 3.01.3.2) with COS afforded the dinuclear complex 145 whose structure was determined crystallographically.36 Other products, not involving boron-sulfur heterocycles and hence outside the scope of this discussion, were obtained via the treatment of 33 with different sulfur reagents such as CS2.36... 

S. P. Nolan, C. D. Hoff. The Heats of Reaction of Phosphines with Toluene-Molybdenum Tricarbonyl. Importance of Both Steric and Electronic Factors in Determining the Mo-Plf Bond Strength. J. Organometal. Chem. 1985, 290, 365-373. 

In [, Pr5C5CoCjHj]+ the (Pr-C5 rotational process is described as slow at 20°C. The coalescence temperature is 65°C in the NMR for the signal of the diastereotopic methyl groups (14). Even in hexaethylbenzene, the barrier to rotation for the ethyl groups is still substantial. For the tricarbonyl chromium and molybdenum complex, AG% was determined as 11.5 kcal/mol (215). 

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