Intervention by an η<sup>6</sup>-Organochromium Moiety Switches Chemoselectivity in Palladium-Catalyzed Reactions with Trialkyltin Compounds
作者:Damien Prim、Jean-Philippe Tranchier、René Chavignon、Françoise Rose-Munch、Eric Rose
DOI:10.1021/om010004s
日期:2001.4.1
The reaction of (chloroarene)tricarbonylchromium with hexaalkylditin under palladium catalysis does not proceed by the expected Stille reaction with addition of an SnR3 group but, instead, affords alkylarene complexesvia a postulated chromium-assisted alkyl migration.
Intramolecular vibrational relaxation in<i>n</i>‐alkyl benzene chromium tricarbonyls: State selective production of chromium atoms
作者:Jeanne M. Hossenlopp、Brian Samoriski、Dan Rooney、J. Chaiken
DOI:10.1063/1.450954
日期:1986.9.15
We have measured one color multiphoton dissociation/ionization (MPD/MPI) spectra for a series of n-alkyl substituted arene chromium tricarbonyls (ACTs). Our data indicate that intramolecular vibrational relaxation (IVR) rates for methyl, ethyl, and propyl ACTs increase relative to the benzene analog in the ratio of 3:6:34. In contrast, the net relaxation rates of the p-xylene (dimethyl) and mesitylene (trimethyl) analogs are two and three times faster than benzene, respectively. The behavior of these latter analogs probably also reflects differences in electronic structure relative to the benzene ACT. Taken with the results of experiments on other analogs and the independently obtained results on the uncomplexed arenes, we have found a strong correlation between the presence of low frequency vibrations and the rate of IVR. The rate of IVR determines the distribution of neutral chromium atoms formed by MPD of the n-alkyl ACTs.