41071-24-3

Upstream product

• 62585-00-6 α-(4-Cyanophenoxy)acetophenone 
• 14609-76-8 4-cyanophenolate 
• 767-00-0 4-cyanophenol 
• 100-47-0 benzonitrile 
• 530-44-9 4-(Dimethylamino)benzophenone 
• 492-22-8 thio-xanthene-9-one 
• 3528-17-4 2,3-dihydro-4H-[1]benzothiopyran-4-one 
• 6051-87-2 3-phenyl-1H-naphtho[2,1-b]pyran-1-one 

Downstream Products

• 14609-76-8 4-cyanophenolate 
• 3328-57-2 sodium 4-cyanophenolate 

Relevant academic research and scientific papers

Direct Irradiation of Phenol and Para-Substituted Phenols with a Laser Pulse (266 nm) in Homogeneous and Micro-heterogeneous Media. A Time-Resolved Spectroscopy Study

Direct irradiation of para-substituted phenols under N2 atmosphere in homogeneous (cyclohexane, acetonitrile, and methanol) and micellar (SDS) solution was investigated by means of time-resolved spectroscopy. After a laser pulse (266 nm), two transient species were formed, viz. the para-substituted phenol radical-cations and the corresponding phenoxy radicals. The radical-cations showed a broad absorption band located between 390 and 460 nm, while the phenoxy radicals showed two characteristic bands centered at 320 nm and 400-410 nm. The deprotonation rate constant of radical-cations (kH) of 105 s-1 and the reaction rate constant of the phenoxy radicals (kR) in the order of 109-1010 M-1·s-1 have been derived. The kH rate constants gave good linear Hammett correlation with positive slope indicating that electron-withdrawing substituents enhance the radical-cation acidity. The binding constants (Kb) of the para-substituted phenols with the surfactant were also measured, and NOESY experiments showed that phenols were located in the hydrophobic core of the micelle. Finally, computational calculations provided the predicted absorption spectra of the transients and nice linear correlations were obtained between the theoretical and experimental energy of the lower absorption band of these species.

Laser flash photolysis study of the reactivity of β-naphthoflavone triplet: Hydrogen abstraction and singlet oxygen generation

The absorption spectra for β-naphthoflavone (1) reveal a solvatochromic red shift in polar solvents which is consistent with the π,π? character of the S0 → S1 electronic transition. The laser flash photolysis technique has been used to characterize and study the reactivity of the triplet excited state of 1. Excitation (355 nm) of degassed solutions of 1, in acetonitrile, resulted in the formation of its corresponding triplet excited state. Addition of hydrogen donors, such as 2-propanol and 1,4-cyclohexadiene, led to triplet quenching and formation of a new transient, which was assigned to the corresponding ketyl radical obtained from a hydrogen abstraction reaction by triplet 1. This ketyl radical was characterized by experiments with methylviologen. The triplet excited state of 1 was efficiently quenched by phenols and N-acetyl l-tryptophan methyl ester. In all cases new transients were formed in the quenching process, which were assigned to the corresponding radical pair resulting from an initial electron transfer from the quencher to the excited naphthoflavone, followed by a fast proton transfer. Singlet oxygen (1O2) is formed from the triplet of 1, and a quantum yield of 0.51 was measured. TDDFT calculations with implicit solvation (IEF-PCM) were used to calculate the ground state UV-vis absorption spectrum, from which the nature of the lowest energy transitions were characterized, and the triplet-triplet absorption spectrum consistent with the triplet transient generated by LFP. Excellent correlation of the calculated and experimental spectra was achieved using the conventional PBE0 hybrid functional.

Phenolic hydrogen abstraction by the triplet excited state of thiochromanone: A laser flash photolysis study

Triplet ketones are known to oxidize biological substrates which can lead to damage of several biomolecules such as amino acids, nucleosides and DNA. As part of our systematic study on the interaction between carbonyl compounds and phenols, the triplet reactivity of thiochromanone (1) towards substituted phenols, in acetonitrile, was investigated employing the laser fash photolysis technique. The quenching rate constants ranged from (1.1 ± 0.1) × 108 L mol-1 s-1 (4-cyanophenol) to (5.8 ± 1.0) × 109 L mol-1 s-1 (hydroquinone). A Hammett plot for the reaction of triplet 1 with phenols containing polar substituents resulted in a reaction constant ρ =-0.90. This negative value observed for the reaction constant ρ is in accord with a mechanism in which the hydrogen transfer from phenols to the triplet carbonyl involves a coupled electron/proton transfer.

Laser flash photolysis study of the photochemistry of thioxanthone in organic solvents

The photoreactivity of the triplet excited state of thioxanthone (TX) was investigated employing the laser fash photolysis technique. The wavelength for the absorption maximum and the lifetime of the triplet excited state are solvent dependent. When hydrogen donor solvents were employed, a new band at 410 nm was observed in the triplet absorption spectrum, which was attributed to the ketyl radical derived from thioxantone. Quenching rate constants, kq, ranged from (1.7 0.1) × 106 L mol-1 s-1 for toluene to ca. 109 L mol-1 s-1 for phenol and its derivatives containing polar substituents, as well as for indole, triethylamine and DABCO.

Bimolecular hydrogen abstraction from phenols by aromatic ketone triplets

Absolute rate constants for hydrogen abstraction from 4-methylphenol (para-cresol) by the lowest triplet states of 24 aromatic ketones have been determined in acetonitrile solution at 23°C, and the results combined with previously reported data for roughly a dozen other compounds under identical conditions. The ketones studied include various ring-substituted benzophenones and acetophenones, α,α,α-trifluoroacetophenone and its 4-methoxy analog, 2-benzoylthiophene, 2-acetonaphthone, and various other polycyclic aromatic ketones such as fluorenone, xanthone and thioxanthone, and encompass n,π*, π,π*(CT) and arenoid π,π* lowest triplets with (triplet) reduction potentials (Ered*) varying from about -10 to -38 kcal mol-1. The 4-methylphenoxyl radical is observed as the product of triplet quenching in almost every case, along with the corresponding hemipinacol radical in most instances. Hammett plots for the acetophenones and benzophenones are quite different, but plots of log log kQ vs Ered* reveal a common behavior for most of the compounds studied. The results are consistent with reaction via two mechanisms: a simple electron-transfer mechanism, which applies to the n,π* triplet ketones and those π,π* triplets that possess particularly low reduction potentials, and a coupled electron-/proton-transfer mechanism involving the intermediacy of a hydrogen-bonded exciplex, which applies to the π,π* ketone triplets. Ketones with lowest charge-transfer π,π* states exhibit rate constants that vary only slightly with triplet reduction potential over the full range investigated; this is due to the compensating effect of substituents on triplet state basicity and reduction potential, which both play a role in quenching by the hydrogen-bonded exciplex mechanism. Ketones with arenoid π,π* states exhibit the fall-off in rate constant that is typical of photoinduced electron transfer reactions, but it occurs at a much higher potential than would be normally expected due to the effects of hydrogen-bonding on the rate of electron-transfer within the exciplex.

Hydroxylamines as oxidation catalysts: Thermochemical and kinetic studies

Bond dissociation enthalpies (BDE) of hydroxylamines containing alkyl, aryl, vinyl, and carbonyl substituents at the nitrogen atom have been determined by using the EPR radical equilibration technique in order to study the effect of the substituents on th

Free electron transfer from several phenols to radical cations of non-polar solvents

Electron-transfer reactions from phenols to parent radical cations of solvents were studied using pulse radiolysis. Phenols bearing electron-withdrawing, electron-donating and bulky substituents were investigated in non-polar solvents such as cyclohexane, n-dodecane, n-butyl chloride and 1,2-dichloroethane. The experiments revealed the direct, synchronous formation of phenoxyl radicals and phenol radical cations in all cases and in nearly the same relative amounts. This was explained by two competing electron-transfer channels which depend on the geometry of encounter between the parent solvent radical cations and the solute phenol molecules. The mechanism is analysed at a microscopic level, treating diffusion as a slow process and the local electron transfer as an extremely rapid event. Furthermore, the effect of various phenol substituents and solvent types on the electron-transfer mechanism and on the decay kinetics of the solute phenol radical cations was analysed. The results were further substantiated using a quantum chemical approach.

Reaction of superoxide with phenoxyl-type radicals

Radiolytically generated phenoxyl radicals derived from the structurally similar phenols cresol, tyrosine, tyramine and tyrosol were reacted with O2·- [k = (1-4.5) × 109 dm3 mol-1 s-1 by pu

Reactivity of substituted phenols toward alkyl radicals

The rate constants for the reaction of primary alkyl radicals with substituted phenolic compounds have been measured in benzene or toluene at room temperature by using the radical clock technique. With three representative phenols, containing in the ortho positions substituents of different size, the kinetics of the hydrogen transfer to alkyl radicals was studied at different temperatures to obtain the corresponding Arrhenius parameters. The kinetic solvent effect on the reaction with α-tocopherol was also investigated in six different solvents behaving as hydrogen bond acceptors, while the reaction with 2,4,6-trimethylphenol and 2,6-di-tert-butylphenol was studied in toluene and γ-valerolactone. For some phenols, the effect of self-aggregation on the kinetic parameters was also studied.

Investigation of the Reactions of Benzonitrile, Ethylbenzene and Cumene with O(3P) in the Gas Phase

The rates of the reaction of benzonitrile, ethylbenzene and cumene with atomic oxygen in the ground state 3P)> have been measured in a discharge flow system with mass spectrometric detection.All measurements were performed in an excess of O-atoms in the temperature range 298 K - 873 K.The following Arrhenius expressions for the bimolecular rate constants were obtained: Benzonitrile k(T) = (1.5 +/- 0.4) * 1013 * exp cm3 * mol-1 * s-1, Ethylbenzene: k(T) = (2.2 +/- 0.4) * 1013 * exp * cm3 * mol-1 * s-1, Cumene: k(T) = (2.0 +/- 0.3) * 1013 * exp cm3 * mol-1 * s-1.Kinetics / O-atoms / Aromatic hydrocarbons / Mass spectrometry