4471-17-4Relevant articles and documents
Intrazeolite photochemistry. 8. Influence of the zeolite physicochemical parameters on the laser flash photolysis of 1,1-diphenyl-2-propanone included in acid faujasites
Cozens, Frances L.,García, Hermenegildo,Scaiano
, p. 11134 - 11140 (1993)
Time-resolved diffuse reflectance laser flash photolysis studies of 1,1-diphenyl-2-propanone (DPA) included in a consistent series of Y faujasites at four levels of Na+-to-H+ exchange have shown that the interaction of this guest molecule with the zeolite acid sites leads to transient spectra much different than that due to the diphenylmethyl radical (DPM) characteristic of nonacidic hosts. Similar modification of the photochemical pattern was also observed when DPA was adsorbed onto the all-Lewis acid site Zn Y zeolite, albeit much slower decay traces were recorded in this case. We have found that by using a highly dealuminated acid zeolite (HYD, Si/Al 27.5) a much better resolved transient spectrum characteristic of the diphenylmethyl cation (DPM+) was obtained. Methanol quenching experiments have provided firm evidence for the generation of DPM+ within acid zeolites. A progressive increase of the DPM/DPM+ ratio, as measured from the relative intensities of their corresponding signals, with the time elapsed from the preparation of the complexes has been observed. Finally, the effects of coadsorbed water and the presence of oxygen on the spectra and the kinetics of the transients generated from DPA are reported.
Quenching of diphenylmethane triplet by energy transfer to diphenylmethyl radical in solution
Fujiwara,Yamasaki
, p. 2525 - 2529 (1998)
Energy transfer from the diphenylmethane triplet to the diphenylmethyl radical in n-heptane solution has been studied by nano-second fluorescence and absorption spectroscopy. Both the triplet and the radical are produced by excitation of diphenylmethane w
Quenching of diphenylmethyl radical fluorescence by cyanoaromatics and phenols
Cyr, Douglas,Das, Paritosh
, p. 8603 - 8623 (2015/02/05)
We have used double-laser nanosecond laser flash photolysis to study the kinetics of bimolecular quenching of the lowest doublet excited state of the transient diphenylmethyl radical (2Ph2CH·) in acetonitrile at 25 °C. We
Kinetic study of the hydrogen abstraction reaction of the benzotriazole-N-oxyl radical (BTNO) with H-donor substrates
Brandi, Paolo,Galli, Carlo,Gentili, Patrizia
, p. 9521 - 9528 (2007/10/03)
The aminoxyl radical (>N-O.) BTNO (benzotriazole-N-oxyl) has been generated by the oxidation of 1-hydroxybenzotriazole (HBT; >N-OH) with a CeIV salt in MeCN. BTNO presents a broad absorption band with λmax 474 nm and e 184
Kinetics of the reaction of the TEMPO radical with alkylarenes
Opeida,Matvienko,Bakurova,Voloshkin
, p. 900 - 904 (2007/10/03)
The kinetics of the reaction of the stable radical 2,2,6,6- tetramethylpiperidine-N-oxyl (TEMPO) with a series of alkylarenes containing primary and secondary benzyl C-H bonds was studied by ESR, and the reaction rate constants were determined. The scheme
