2348-47-2

Upstream product

• 620-13-3 1-bromomethyl-3-methyl-benzene 
• 35509-94-5 1-(iodomethyl)-3-methylbenzene 
• 60-29-7 diethyl ether 
• 64-17-5 ethanol 
• 78-78-4 methylbutane 
• 108-38-3 m-xylene 
• 620-14-4 1-Methyl-3-ethylbenzene 
• 626-16-4 3-(chloromethyl)benzyl chloride 
• 83598-09-8 1,3-bis(3-methylphenyl)propan-3-one 
• 3229-40-1 phthalimide N-oxyl 
• 119-61-9 benzophenone 
• 620-19-9 1-chloromethyl-3-methyl-benzene 

Relevant academic research and scientific papers

Kinetic Study of the Phthalimide N-Oxyl Radical in Acetic Acid. Hydrogen Abstraction from Substituted Toluenes, Benzaldehydes, and Benzyl Alcohols

The phthalimide N-oxyl (PINO) radical was generated by the oxidation of N-hydroxyphthalimide (NHPI) with Pb(OAc)4 in acetic acid. The molar absorptivity of PINO. is 1.36 × 103 L mol -1 cm-1 at λmax 382 nm. The PINO radical decomposes slowly with a second-order rate constant of 0.6 ± 0.1 L mol-1 s-1 at 25°C. The reactions of PINO . with substituted toluenes, benzaldehydes, and benzyl alcohols were investigated under an argon atmosphere. The second-order rate constants were correlated by means of a Hammett analysis. The reactions with toluenes and benzyl alcohols have better correlations with σ+ (ρ = -1.3 and -0.41), and the reaction with benzaldehydes correlates better with σ (ρ = -0.91). The kinetic isotope effect was also studied and significantly large values of kH/kD were obtained: 25.0 (p-xylene), 27. 1 (toluene), 27.5 (benzaldehyde), and 16.9 (benzyl alcohol) at 25°C. From the Arrhenius plot for the reactions with p-xylene and p-xylene-d10, the difference of the activation energies, EaD - E aH, was 12.6 ± 0.8 kJ mol-1 and the ratio of preexponential factors, AH/AD, was 0.17 ± 0.05. These findings indicate that quantum mechanical tunneling plays an important role in these reactions.

Kinetics of the reaction of the TEMPO radical with alkylarenes

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

Reaction pathways involved in the quenching of the photoactivated aromatic ketones xanthone and 1-azaxanthone by polyalkylbenzenes

The reactions of the photoexcited aromatic ketones, xanthone and 1-azaxanthone, with polyalkylbenzene donors yields the corresponding ketyl radicals as detected by nanosecond laser flash photolysis. On the basis of formation of these photoreduced products, the quenching of the photoexcited species is expected to occur either by a one-step hydrogen abstraction from the donor, electron transfer followed by proton transfer from the donor, or by formation of a charge-transfer type encounter complex prior to hydrogen atom transfer. The reactions of triplet xanthone and triplet 1-azaxanthone with polyalkylbenzene donors in acetonitrile were investigated to probe the effect of the nature of the triplet state and the redox properties on the relative importance of each quenching pathway. Determination of bimolecular rate constants, as well as analysis of kinetic isotope effects and ketyl radical yields, suggests that for both xanthone and 1-azaxanthone the quenching process is dominated by formation of charge-transfer encounter complexes between excited-state aromatic ketone acceptor and ground-state polyalkylbenzene donor. The reactivites of the xanthone π,π* triplet and 1-azaxanthone n,π* triplet toward these donors is shown to be governed by their reduction potentials, with their electronic configuration being unimportant to the kinetics of encounter complex formation. The only exception to this is found when sterically encumbered polyalkylbenzene donors are employed. Results with these compounds suggest that π,π* and n,π* states form encounter complexes of different structure which affects their ability to react with hindered donors. Additionally, product yields with all of the donors are controlled by both the extent of charge transfer within encounter complexes and the encounter complex structure.

Laser photolysis investigation of induced quenching in photoreduction of benzophenone by alkylbenzenes and anisoles

The quenching processes of triplet benzophenone (JBP) by alkylbenzenes (AB) and anisole derivatives (AD) in benzene (Bz) and a mixture of acetonitriie (ACT-,) and water (4 :1 v/V; have been studied on the basis of rate constants and efficiencies determined by nanosecond laser flash photolysis a; 355 n m at 295 K. It was found that (1) the deactivation of 3BPby ADs in ACN H2O (4 :1 v/v) was governed by electron transfer (ET) to produce the benzophenone anion (BP'~) and corresponding cation (AD' + ) radicals wiih efficiencies, atj 1 whereas no chemical species were formed in Bz; and 2) photoreduction of 3BPby ABs resulted in benzophenone ketyl radical (BPK) formation by benzylic hydrogen abstraction (HA) with efficiencies XHA 1 in 3z and ACN-H2O (4 :1 v/v). The residual efficiency (a: 1 -ET or ! -aH/1) was attributed to a birnolecular process with no photochemical product, which was named 'induced-quenching (IQf. The quenching rate constants (Jcq) of ;'BPby ADs and ABs were less than the diffusion limits of both Bz and AC1~H2O (4 :1 v/v). The net bimolecular rate constants for the ET, HA and IQ processes were estimated from the k values and efficiencies. The rate constants (%T and k,Q) of ET and IQ with AD versus the oxidation potential (￡) of AD followed Rchm-Weller behaviour while logarithmic rate constants {/CHA and ki(j) of HA and IQ by ABs increased linearly with a decrease in the Em of AB. It was suggested, for the deactivation mechanism of 3BPby ABs and ADs (RH), that ;1) the IQ process was intersystem crossing (ISC) enhanced by the partial charge transfer (CT) character of the triplet excipiexes, 3(BP"~- A-RHa + )a,e; (2) radical ion formation by ET might be accomplished in a polar solvent by further CT interaction in the excipiex; (3) the process of BPK formation was inferred to be H-atom transfer in the exciplex, where the more protic H-atom was readily mobile, rather than ET followed by proton transfer and (4) the loss of efficiencies of photochemicalproduct formation was derived not from back ET but from the IQ process, inherent to photoreactions, via triplet excipiexes. The deactivation processes of 3BPby RH are illustrated in Scheme 1. I ET BP'- + RH'(3BP' + RHJcoj -3(BPO- RHg,.-BPK 4 R' BP + RH Scheme 1.

One-Electron Oxidation of Alkylbenzenes in Acetonitrile by Photochemically Produced NO3.: Evidence for an Inner-Sphere Mechanism

The reaction between NO3. and polyalkylbenzenes was studied using 308-nm laser flash photolysis of cerium(IV) ammonium nitrate in the presence of the alkylbenzenes in acetonitrile solution.For all benzenes, with the exception of monoalkylbenzenes and o- and m-xylene, the reaction with NO3. was found to yield the corresponding radical cations and to proceed in an apparently straightforward bimolecular manner.For monoalkylbenzenes and o- and m-xylene, radicals were seen which are derived from the parents by formal loss of H. from the side chain of the aromatic.This reaction proceeds via a complex between the aromatic and NO3. with the decomposition of the complex being rate determining at higher concentrations of aromatic (rate constants for decomposition between 6 * 105 and 4 * 107 s-1).In the complex, electron transfer from the aromatic to NO3. is suggested to be concerted with deprotonation of the incipient radical cation.Formation of a complex between NO3. and aromatics is likely even in those cases where radical cations are observed, with the assumption that in these cases the complex decomposition rate is greater than 6 * 107 s-1.

The mechanism of formation of m-xylylene type biradicals produced by photolysis of polymethyl benzenes or dihalomethyl benzenes

The mechanism of formation of the mesitylylene biradical (3) produced by short-wavelength photolysis of matrix-isolated mesitylene (1) has been investigated. The data rule out a mechanism involving the sequential formation of the biradical 3 via photolysi

C-C and C-H Bond Splits of Laser-Excitated Aromatic Molecules. 1. Specific and Thermally Averaged Rate Constants

Toluene, m-,o-,and p-xylene, mesitylene, ethyl-, isopropyl-, and tert-butylbenzene were irradiated by nanosecond laser flashes at 193 nm.After fast internal conversion to the electronic ground state, the molecules dissociate by C-C or C-H bond splits.The

Kinetic Study for Reactions of Nitrate Radical (NO3.) with Substituted Toluenes in Acetonitrile Solution

The absolute rate constants for the reactions of the nitrate radical (NO3.) with substituted toluenes in acetonitrile have been determined by the flash photolysis method.From the plots of the rate constants against the ionization energies, it was revealed that the reaction path for toluene derivatives with low ionization energies is different from that for toluene derivatives with high ionization energies.For toluene, a deuterium isotope effect was observed to be ca. 1.6, suggesting the direct hydrogen atom abstraction reaction; in this group, xylenes and p-chlorotoluene belong.For toluene derivatives with electron-withdrawing substit uents, NO3. may add to the phenyl rings followed by successive reactions.For both groups, linear correlations against ionization energies with negative slopes show that NO3. is highly electrophilic and that strong polar effects exist in the transition states of both reactions.For toluenes with methoxy groups, the electron-transfer reaction from methoxytoluene to NO3. is a main initial path, since the transient absorption band due to the cation radical of methoxytoluene was detected.