Evidence for heterolytic cleavage of C-S bonds in the photolysis of 1,3,5-trithianes

Hug, G.L., Janeba-Bartoszewicz, E., Filipiak, P., Pedzinski, T., Kozubek, H. and Marciniak, B.

Polish J. Chem. 82, 883-892 (2008)

NDRL 4749

The hemolytic/heterolytic nature of photolytic C-S bond cleavage was studied in 1,3,5-trithianes. The mechanism of photolysis was refined from previous studies. First, evidence was presented for the existence of a precursor of the biradical-like transient (I) which itself was identified in previous studies. Second, the nature of I was further clarified through methanol-scavenging experiments where the results could be interpreted as lending credibility to the notion that I has significant bipolar character. Kinetic and spectral analyses of transient absorptions, following laser excitation of the trithianes, showed that I was reacting with methanol. Complementary steady-state photolytic quantum yields supported this finding, and additional, but unidentified, stable products from irradiations in methanol were seen in the HPLC. The formation of these products was interpreted as likely arising from a nucleophilic attack of methanol at the carbocationic end of the bipolar structure of I.

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