Tracking "invisible" alkylchlorocarbenes by their sigma --> p absorptions: dynamics and solvent interactions.
Contrary to implications in the literature, the sigma --> p absorptions of alkylchlorocarbenes (RCCl) are readily acquired by laser flash photolysis with UV-vis detection in solution at ambient temperature. Examples include RCCl with R = methyl, benzyl, t-butyl, 1-adamantyl, and cyclopropyl. These absorptions permit direct monitoring of carbene reactions and the formation of carbene-solvent complexes. The kinetics of the reactions of "free" and complexed MeCCl and PhCH2CCl were directly followed with tetramethylethylene and 1-hexene. Particularly effective complexation was provided by anisole and 1,3-dimethoxybenzene, which modulated the rates of intermolecular carbene additions. Computational studies are presented, which aid in understanding the carbene absorption spectra and the nature of the solvent complexes.
Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08903, USA. moss@rutchem.rutgers.edu
Robert A
RA
Moss
Jingzhi
J
Tian
Ronald R
RR
Sauers
Karsten
K
Krogh-Jespersen