76241-30-0Relevant academic research and scientific papers
Free electron transfer mirrors rotational conformers of substituted aromatics: Reaction of benzyltrimethylsilanes with n-butyl chloride parent radical cations
Brede, Ortwin,Hermann, Ralf,Naumov, Sergej,Zarkadis, Antonios K.,Perdikomatis, Gerasimos P.,Siskos, Michael G.
, p. 2267 - 2275 (2007/10/03)
The rotation motion of a larger substituent of an aromatic ring is accompanied by the electron density fluctuation of the highest occupied molecular orbitals. For benzyltrimethylsilanes p-R3-C 6H4-○-CR1-R2
Photochemistry and photophysics of (p-benzoylphenyl)diphenylmethyl and (p-benzoylphenyl)bis(4-tert-butylphenyl)methyl radicals in different solvents
Jarikov, Viktor V.,Nikolaitchik, Alexandre V.,Neckers, Douglas C.
, p. 5131 - 5140 (2007/10/03)
The photochemical reactions of (p-benzoylphenyl)diphenylmethyl (1) and (p-benzoylphenyl)bis(4-tert-butylphenyl)methyl (2) in various solvents were investigated. The photophysical parameters of the first excited doublet state of the radicals were measured using spectroscopic and kinetic methods and led to a 'molecular rotor' model to characterize the excited-state behavior. The charge-transfer excited state for both radicals was observed. Photoproducts separated from the photolysis of 1 and 2 in benzene suggest photodecomposition proceeds via H-abstraction (55%), fragmentation (20%), cyclization (10%), and addition (10%).
Sterically Hindered Free Radicals. 18. Stabilization of Free Radicals by Substituents As Studied by Using Triphenylmethyls
Neumann, Wilhelm P.,Penenory, Alicia,Stewen, Ulrich,Lehnig, Manfred
, p. 5845 - 5851 (2007/10/02)
The relative stabilization of 10 4-mono- and 24 4,4'-disubstituted triphenylmethyl radicals 1 has been measured by recording the degree of dissociation of the corresponding quinonoid dimers 2 by means of ESR.The following substituents or combinations of t
Sterically Hindered Free Radicals, XIII. Wittig's Radical 4-Benzoyltriphenylmethyl and Analogous Mono-4-substituted Trityl Radicals
Zarkadis, Antonios K.,Neumann, Wilhelm P.,Uzick, Wolfram
, p. 1183 - 1192 (2007/10/02)
The mono-4-R-triphenylmethyl radicals 1, 8b-f, R = tBu, CF3, COMe, COPh, CN, Me, or their quinonoid dimers 4, 9b-f are prepared, most of them for the first time.The degree of dissociation of the latter at 25 deg C is surprisingly high (=/ 33percent, 0.01 M), donors and acceptors being effective here likewise.ESR data are given and discussed.
LANGLEBIGE α-METALLIERTE METHYLRADIKALE UND DEREN DIMERE
Hillgaertner, Horst,Neumann, Wilhelm P.,Schulten, Winfried,Zarkadis, Antonios K.
, p. 197 - 211 (2007/10/02)
Persistent radicals R'2C-MR3 (I), R'C(MR3)2 (II) and RC(MR3)OMR3 (III), R'=mostly Ph but also t-Bu, H, R'2=also 9-fluorenyl or 9-xanthenyl, M=Si, Ge, Sn, have been generated from the corresponding C-H or C-Hal compounds or by addition of R3M to ketones.Radicals I, II and III are investigated by ESR spectroscopy.A temperature-dependent equilibrium has been found between these radicals and their dimers (IV), of, as far as investigated, quinonoid structure.Dimers IV rearrange with acids giving diaryl methanes.Autoxidation of radicals I at 80 deg C gives thebenzpinacol derivatives, whose radicals are oxidized again, undergoing different fragmentations.At room temperature, however, the dimers IV are attacked by O2 forming the metalated benzophenone derivatives via fragmentation, which are split by UV light into the radicals R3M (M=Si, Ge, Sn) and the oxyl radicals, which are highly stabilised by mesomerism.
