ISSN:
0570-0833
Keywords:
Photochemistry
;
Azoalkanes
;
Strained molecules
;
Alkenes
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The possibility to excite directly at 185 nm chromophores that absorb in the vacuum-UV has stimulated increased activity during the last decade in this field of photochemistry. Whereas photochemical reactions at λ〈200 nm have been thoroughly investigated in the gas phase, only recently have intensive studies on the 185-nm photochemistry of organic compounds in solution provided new insights. Despite the high excitation energies, selective photoreactions are promoted in the short-lived singlet excited states (Rydberg photochemistry). In contrast to conventional photochemistry (λ 〉 220 nm), 185-nm irradiation preferentially results in intramolecular rearrangement, fragmentation, and isomerization reactions. Intermolecular radical couplings and abstractions as well as dimerizations (π, π*-excitation) compete minimally. Besides the straightforward denitrogenation of photoresistant (“reluctant”) azoalkanes, important applications of the short-wavelength photolysis are also found in technology (photolithography) and medicine (193-nm laser). Broadening the scope of the synthetic potential of the 185-nm photochemistry, which so far has been limited to direct cis/trans isomerizations, presents a challenge for the chemist.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/anie.198606613
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