Arene Thiocarbonyl Chromium O Complexes

Thesis, McGill University, Montreal, Quebec, Canada, 1976. 

Submitted by GERARD JAOUEN and GERARD SIMONNEAUX Checked by IAN S. BUTLERt and DANIEL COZAK  

The preparations of several (arene)(thiocarbonyl)chromium(0) complexes bearing electron-donating and/or electron-withdrawing substituents on the ring are described here (A-E). This type of compound is useful in organometallic chemistry for problems related to stereochemistry around a chromium atom6 and in organic chemistry in the activation of arene substituents with respect to alkylation.7 

The intermediate cyclooctene complex appears to be more reactive with respect to CS coordination and more sensitive to oxidation when the arene ring bears electron-withdrawing groups (e.g., C02CH3). Dicarbonyl(methyl rj6-benzoate)-thiocarbonyl)chromium is air stable in the solid state and reasonably stable in solution.9 The infrared spectrum exhibits metal carbonyl absorptions at 1980 and 1935 cm 1 and a metal thiocarbonyl stretch at 1215 cm 1 (Nujol) (these occur at 1978, 1932, and 1912 cm 1 in CH2C12 solution).10 Irradiation of the compound in the presence of phosphite or phosphine leads to slow substitution of CO by these ligands, whereas the CS ligand remains inert to substitution. The crystal structure has been published.  

DICARBONYL(METHYL r/6-m-METHYLBENZOATE)(THIO-CARBONYL)CHROMIUM(O) 

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