14941-51-6Relevant academic research and scientific papers
Thermal rearrangement, XXV: The automerization of benzene as a radical-initiated reaction
Zimmermann, Gerhard,Nuechter, Matthias,Hopf, Henning,Ibrom, Kerstin,Ernst, Ludger
, p. 1407 - 1411 (2007/10/03)
The thermal isomerization of [1,4-D2]-(3a) and [1,2-13C2]benzene (1a) has been studied in excess hydrogen at 750-850°C with contact time less than 1.2 s and very low partial pressure in a quartz flow system. In both cases, the main isomerization products are the corresponding meta isomers. The data suggest a radical intramolecular interchange of the benzene carbon atoms by 1,2-C shifts. The multistep reaction cascade is initiated by H addition to the benzene ring followed by transannular homoallyl rearrangements involving the intermediate formation of bicyclo[3.1.0]hexenyl and cyclopentadienylmethyl radicals. This pathway constitutes a side reaction competing with the direct stabilization of the cyclohexadienyl radicals formed preferentially at high temperature. VCH Verlagsgesellschaft mbH, 1996.
PURE ROTATIONAL SPECTRA OF 1,2- AND 1,3-BENZENE-d2 OBSERVED BY MICROWAVE FOURIER TRANSFORM SPECTROSCOPY
Oldani, M.,Widmer, R.,Grassi, G.,Bauder, A.
, p. 31 - 40 (2007/10/02)
The pure rotational spectra of 1,2- and 1,3-benzene-d2 have been measured over the 8-18 GHz range with a pulsed microwave Fourier transform spectrometer.Rotational constants have been determined from the measured transition frequencies.Structur
Isotope Effects in Arene C-H Bond Activation by
Jones, William D.,Feher, Frank J.
, p. 4814 - 4819 (2007/10/02)
The isotope effects involved in the activation of arene C-H bonds by the intermediate have been investigated.The ratio kH/kD for coordination to a double bond in benzene (the rate-determining step of arene activation) is found to be 1.05(6), whereas kH/kD=1.4 for the second step in which the C-H bond of the coordinated arene undergoes oxidative addition.The isotope effect KH/D for the equilibrium between the more stable phenyl hydride complex (C5Me5)Rh(PMe3)(C6D5)H and the complex containing hydrogen in the ortho position of the phenyl ring (C5Me5)Rh(PMe3)(o-C6D4H)D shows a preference for hydrogen (vs. deuterium) on the metal of 2.7.The kinetic isotope effect for reductive elimination and dissociation of m-xylene from (C5Me5)Rh(PMe3)(3,5-C6H3Me2)H vs. (C5Me5)Rh(PMe3)(3,5-C6H3Me2)D is found to be inverse, with kH/kD=o.51.Analysis of the data for the deuterated benzene derivatives confirms that the kinetic isotope for the reductive elimination step is inverse.Attemps to prepare the complex (C5Me5)Rh(PMe3)(CH3)D by reduction of + with - resulted in the formation of both (C5Me5)Rh(PMe3)(CH3)D and (C5Me5)Rh(PMe3)(CH2D)H.
