24599-57-3

Basic information

• Product Name: cyclohexa-2,4-dien-1-one
• Synonyms: 2,4-Cyclohexadienone; cyclohexadienone
• CAS NO: 24599-57-3
• Molecular Formula: C₆H₆O
• Molecular Weight: 94.1112
• Mol File: 24599-57-3.mol

Chemical Properties

• Boiling Point: 182.4°C at 760 mmHg
• Flash Point: 57.3°C
• Density: 1.051g/cm³
• Vapor Pressure: 0.81mmHg at 25°C
• Refractive Index: 1.515
• CAS DataBase Reference: cyclohexa-2,4-dien-1-one(CAS DataBase Reference)
• NIST Chemistry Reference: cyclohexa-2,4-dien-1-one(24599-57-3)
• EPA Substance Registry System: cyclohexa-2,4-dien-1-one(24599-57-3)

Safety Data

• Hazardous Substances Data: 24599-57-3(Hazardous Substances Data)

Upstream product

• 93-99-2 benzoic acid phenyl ester 
• 19252-52-9 propylium 
• 17660-74-1 bicyclo[2.2.2]oct-7-ene-2,5-dione 
• 2220-40-8 bicyclo[2.2.2]oct-5-en-2-one 
• 108-95-2 phenol 
• 71-43-2 benzene 
• 622-86-6 2-chloroethoxybenzene 

Downstream Products

• 34890-28-3 1-(Cyclohexa-1,3-dienyl)-pent-4-en-1-on 
• 34890-24-9 3,4,4a,5,6,8a-Hexahydro-1H-1,6-methano-naphthalen-2-one 
• 108-95-2 phenol 
• 773095-64-0 2-(2-ethynylphenyl)-1,3-dioxolane 
• 1610735-40-4 1-((allyloxy)(phenyl)methyl)-2-ethynylbenzene 
• 913192-84-4 phenyl[2-[(trimethylsilanyl)ethynyl]phenyl]methanol 

Relevant articles and documents

Photochemical reaction of ozone and benzene: An infrared matrix isolation study

The photolysis of benzene/ozone mixtures in an argon matrix at 12 K with UV light of λ ≥ 280 nm leads to the following products: phenol, 2,4-cyclohexadienone, benzene oxide, and butadienylketene (hexa-1,3,5-trien-1-one). The identification of butadienylketene as a product is based on deuterium isotopic shifts and agreement with density functional vibrational frequency calculations. We find an average phenol/ butadienylketene branching ratio of 4.3 during the course of photolysis. This is the first report in the literature of the observation of a ketene product from the reaction of oxygen atoms with benzene.

Ketonization equilibria of phenol in aqueous solution

The two keto tautomers of phenol (1), cyclohexa-2,4-dienone (2) and cyclohexa-2,5-dienone (3), were generated by flash photolysis of appropriate precursors in aqueous solution, and the pH-rate profiles of their enolization reactions, 2 → 1 and 3 → 1, were measured. The rates of the reverse reactions, 1 → 2 and 1 → 3, were determined from the rates of acid-catalyzed hydron exchange at the ortho- and para-positions of 1; the magnitude of the kinetic isotope effect was assessed by comparing the rates of hydrogenation of phenol-2t and -2d. The ratios of the enolization and ketonization rate constants provide the equilibrium constants of enolization, pKE(2, aq, 25°C) = -12.73 ± 0.12 and pKE(3, aq, 25°C) = -10.98 ± 0.15. Combination with the acidity constant of phenol also defines the acidity constants of 2 and 3 through a thermodynamic cycle. These ketones are remarkably strong carbon acids: pKa(2) = -2.89 ± 0.12 and pKa(3) = -1.14 ± 0.15. They disappear by proton transfer to the solvent with lifetimes, τ(2) = 260 μs and τ(3) = 13 ms, that are insensitive to pH in the range from 3-10.

Reaction of Ammonia with Accelerated Benzoyl Ions under Multiple-collision Conditions in a Triple Quadrupole Instrument

The reaction of benzoyl ion with ammonia in multiple-collision conditions in the second quadrupole assembly of a triple quadrupole mass spectrometer at (laboratory) ion kinetic energies from 0 to 20 eV produced the even-electron ions +, m>+ (m=0,1) and + (n=0,1,2,3) and the odd-electron ions p>+. (p=0,1).Thermochemical information could not be obtained under multiple-collision conditions: both exotermic and endotermic reactions were observed, with no translational-energy onset measurable for the endothermic pr/cesses, nor decrease in the yield of the exothermic processes at high energies.The behaviour of cluster-ions intensities as pressure varied was qualitatively as expected.There are pressure and energy regions where spectra change little; if this feature were to be general, it would point to some utility for these conditions in qualitative analysis.

Photodissociation Study of C6H6O+. Ions in an Ion Cyclotron Resonance Spectrometer

Tautomeric phenol and 1,3-cyclohexadien-5-one radical cations exist as distinct, stable species in the gas phase.This is established by a study of the photodissociation spectra of C6H6O+. ions generated from four sources.Specifically, the ionized phenol and the C6H6O+. from phenetole exist principally as the phenol structure.On the other hand, C6H6O+. generated from bicyclooct-2-ene-5,7-dione and 2-phenoxyethyl chloride exist as a mixture of keto and enol structures.

REACTIONS RETRODIENIQUES - X. OBTENTION PAR REACTION DE RETRO-DIELS-ALDER DE CETONES TAUTOMERES DE PHENOLS.

Several unstable ketones, tautomers of phenols, have been obtained by flash thermolysis of Diels-Alder adducts and identified by their IR and UV spectra at -196 deg C.