In:
Photochemistry and Photobiology, Wiley, Vol. 22, No. 1-2 ( 1975-07), p. 19-27
Abstract:
Abstract— By means of in situ photolysis EPR of aqueous solutions of α‐oxocarboxylic acids (RCO‐CO 2 H) at pH values above 5, semidione radical anions [RC(O ‐ )=C(O‘)R] and α‐hydroxy‐α‐carboxy alkyl radicals [RC(OH)CO 2 ‐] were detected. C0 2 was identified as a reaction product. On photolysis of mixtures of α‐oxocarboxylic acids (RCOCO 2 H and R'COCC 2 H), “mixed” semidione radical anions [RC(O ‐ 〉 =C(O)R’] were observed in addition to RC(O ‐ )=C(O‘)R, R'C(O ‐ )=C(O’)R‘, RC(OH)CO 2 ‐ and R'C(OH)CO 2 ‐ . The experimental results are explained in terms of photodecarboxylation (α‐clea‐vage) of electronically excited RCOCOJ to yield RCO and CO 2 . The radicals RC(OH)CO 2 ‐ are formed by reduction of RCOCO 2 ‐ by CO 2 ‐ . The semidione radicals are produced by addition of RCO to RCOCO 2 ‐ followed by decarboxylation of the intermediate adduct. This mechanism was confirmed by generating acyl radicals independently and reacting them with α‐oxocarboxylic acids. Selected product studies support the mechanism suggested.
Type of Medium:
Online Resource
ISSN:
0031-8655
,
1751-1097
DOI:
10.1111/php.1975.22.issue-1-2
DOI:
10.1111/j.1751-1097.1975.tb06715.x
Language:
English
Publisher:
Wiley
Publication Date:
1975
detail.hit.zdb_id:
2048860-9
SSG:
12
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