71254-82-5Relevant academic research and scientific papers
Dynamics of Radical Pair Reactions in Micelles
Gould, I. R.,Zimmt, M. B.,Turro, N. J.,Baretz, B. H.,Lehr, G. F.
, p. 4607 - 4612 (1985)
The time-resolved behavior of sec-phenethyl, cumyl, and diphenylmethyl radicals as radical pairs solubilized in micelles has been observed using pulsed laser photolysis.The decay of the micellized radical pairs consists of a fast component (20-2000*10-9 s), attributed to reaction within the geminate radical pair, and a slow component (>2000*10-9 s), attributed to reactions from random encounters of radicals.The extent of geminate pair reaction (micellar cage reaction) depends upon the competition between the rate constants for reaction and diffusive separation.The rate constants for the reaction and diffusion processes are determined and the nature of these processes is discussed.A correlation is found between the extent of fast decay observed in the time-resolved experiments and the extent of cage reaction determined from steady-state photolysis.
Hammett analysis of photodecarbonylation in crystalline 1,3-diarylacetones
Resendiz, Marino J. E.,Garcia-Garibay, Miguel A.
, p. 371 - 374 (2007/10/03)
(Chemical Equation Presented) The relative quantum yields and chemical efficiencies of crystalline p,p′-disubstituted 1,3-diphenyl-2-propanones with 4-MeO, 4-Me, 4-F, 4-CF3, and 3,4-diMeO groups were determined by parallel irradiation of polycrystalline samples. Variations in quantum yields that span a factor of 4 are analyzed in terms of the effects of substituents on the stability of the benzylic radical. All solid-state reactions proceeded with 100% chemoselectivity and in >95% chemical yield.
Alkali metal ion controlled product selectivity during photorearrangements of 1-naphthyl phenyl acylates and dibenzyl ketones within zeolites
Warrier,Kaanumalle, Lakshmi S.,Ramamurthy
, p. 620 - 631 (2007/10/03)
Photochemical behaviors of 1-naphthyl phenyl acylates and dibenzyl ketones included in zeolites have been compared. 1-Naphthyl phenyl acylates while in solution produce eight photoproducts; within NaY it gives a single product. The selectivity is attributed to the restriction brought on the mobility of the primary radical pair by the alkali metal ions present in zeolites. Photochemistry of dibenzyl ketones within NaY reveals that the intersystem crossing in caged radical pairs could be influenced by the heavy alkali metal ions. Structures of complexes among Li+ ion and the guest 1-naphthyl phenyl acetates and dibenzyl ketone computed at the B3LYP level have been useful to understand the origin of the observed product selectivity within zeolites.
13C magnetic resonance studies. 142. The fate of highly substituted acyclic ketones in strong base: β-enolization, Haller-Bauer cleavage, and an alkyl to aryl acyl shift
Dyllick-Brenzinger, Rainer A.,Patel, Vijay,Rampersad, Mollin B.,Stothers, J. B.,Thomas, Shirley E.
, p. 1106 - 1115 (2011/08/10)
Di-tert-butyl ketone (2a), 5,5,7,7-tetramethyl-6-undecanone (2b), and 2,4-dimethyl-2,4-diphenyl-3-pentanone (2d) have been found to undergo slow rearrangement by β-proton abstraction from the α-methyl groups upon treatment with t-BuO-/t-BuOH/>185 deg C.This is in contrast to the absence of such rearrangement in cyclic systems.It is the only significant process observed for 2a and 2b, whereas with 2d and its monomethyl analog 22 Haller-Bauer type cleavage and an unprecedented 1,3-acyl shift from sp3 to sp2 carbon accompany the β-enolate rearrangement.The rates of 1H/2H exchange of the methyl protons in 2a, b were found to be similar to those reported for a variety of cyclic systems but this exchange does not occur in 2d, where only aryl proton exchange was observed.
