24436-61-1Relevant academic research and scientific papers
Protonation of Diarylcarbenes by Alcohols: The Importance of Ion Pair Dynamics
Dix, Edward J.,Goodman, Joshua L.
, p. 12609 - 12612 (2007/10/02)
Picosecond laser excitation of either di(p-chlorophenyl)- or di(p-methoxyphenyl)diazomethane generates a transient which we ascribe to the singlet states of di(p-chlorophenyl)- and di(p-methoxyphenyl)carbenes, 1a and 1b, respectively.Picosecond absorption spectroscopy is used to determine their kinetic behavior in various solvents.In the presence of alcohols, these carbenes are protonated, forming contact-ion pairs.These ion pairs partition between collapse to ether products and separation to free carbenium ions, 2a and 2b, which are readily observed.The dynamics of these ion pairs is discussed.Protonation of carbenes can provide an alternative method for the preparation of ion pairs and the investigation of their dynamics.
The Absolute Kinetics of Several Reactions of Substituted Diphenylcarbenes
Hadel, L. M.,Maloney, V. M.,Platz, M. S.,McGimpsey, W. G.,Scaiano, J. C.
, p. 2488 - 2491 (2007/10/02)
4,4'-dibromo-, 4-bromo-, 4,4'-dichloro-, 4-chloro-, 4-methyl-, 4,4'-dimethyl-, 4-phenyl-, 4-carbomethoxyl-, 4-cyano-, 4-cyano-4'-methyl-, and 4,4'-dimethyldiphenyldiazomethane were studied by laser flash photolysis.Excitation of the diazo compounds at 308 nm produced the corresponding diarylcarbenes.The kinetics of the reaction of the substituted carbenes with alkanes and methanol were examined.Hydrogen abstraction rates are largely insensitive to ring substitution, while the methanol reaction is accelerated considerably by p-methyl substitution and retarded by a para electron-withdrawing substituent.
