ORGN 640 |
| The meta effect for the photochemistry of methoxy-substituted arylmethyl systems was first reported for the photosolvolysis of benzylic esters by Howard Zimmerman in two sequential publications in 1963. Since those seminal publications, the enhanced reactivity of meta- (and ortho-) substituted derivatives over the corresponding para analogues has been observed in many photoreactions. As has been reported in detail, we have re-examined and expanded on the initial results for arylmethyl esters. More recently, we have been examining this effect for a variety of systems where only radical intermediates are involved (arylmethyl esters in cyclohexane, the photo-Claisen reaction in both cyclohexane and methanol) and where ionic intermediates are involved (photoadditions of alcohols to stilbenes and diarylacetylenes). The effect of temperature on fluorescence quantum yields and excited singlet state lifetimes has been a valuable probe for determining the photochemical reactivity in these systems. |
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Sixty Years of Physical Organic Chemistry
8:10 AM-12:00 PM, Wednesday, August 22, 2007 BCEC -- Ballroom, Oral
Division of Organic Chemistry |