| Abstract
| - UV photolysis of methyltrioxorhenium, CH3ReO3, isolated in an argon matrix at ca. 14 K results in tautomerization to the methylidene derivative H2CRe(O)2OH, the properties of which have been determined. The mechanism of the change is discussed, as is the relevance of the tautomeric product to the catalytic action of CH3ReO3 in olefin metathesis.
- IR spectroscopic measurements have been used to chart the reactions activated byirradiating argon matrices doped with methyltrioxorhenium, CH3ReO3 (1), first with lightat wavelengths near 254 nm and subsequently with broad-band UV−visible light (200 ≤ λ≤ 800 nm). Assignments of the IR absorption bands are made and their carriers identifiedon the basis of experiments with CD3ReO3 or 13CH3ReO3 and by comparison either with thevibrational properties forecast by density functional theory (DFT) calculations or with thoseof related molecules. Photoexcitation at λ = ca. 254 nm results in tautomerization of CH3ReO3 to the methylidene derivative H2CRe(O)2OH (2), the properties of which have beendetermined, partly by experiment and partly by DFT calculations. The mechanism of thechange is discussed, as is the relevance of the tautomeric product to the catalytic action ofCH3ReO3 in olefin metathesis. Broad-band UV−visible radiation leads to the formation of arhenium carbonyl, 3, possibly the Re(V) compound H2Re(CO)(O)OH.
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