6711-19-9

Usage

InChI:InChI=1/C7H7/c1-7-5-3-2-4-6-7/h2-6H,1H2/q-1

Upstream product

• 46504-11-4 1-benzyl-2,4,6-trimethyl-pyridinium 
• 33372-10-0 tropylium bromide 
• 100-39-0 benzyl bromide 
• 14804-25-2 tert-butyl cation 
• 100-44-7 benzyl chloride 
• 103-29-7 bibenzyl radical cation 
• 108-88-3 toluene radical cation 
• 100-41-4 ethylbenzene radical cation 
• 132434-74-3 methylsilyl cation 
• 100-46-9 benzylamine 
• 74-88-4 methyl iodide 
• 71-43-2 benzene 
• 18851-76-8 trifluoromethylium 
• 60-12-8 2-phenylethanol 

Downstream Products

• 100-44-7 benzyl chloride 
• 109418-69-1 C₈H₈ClO⁽¹⁺⁾ 
• 14804-25-2 tert-butyl cation 
• 109418-67-9 C₈H₉S⁽¹⁺⁾ 
• 60154-94-1 3-methyl-benzylium 
• 40057-92-9 3,5-dimethyl-benzylium 
• 109418-70-4 C₈H₈FO⁽¹⁺⁾ 
• 109418-74-8 C₈H₈ClS⁽¹⁺⁾ 
• 109418-77-1 C₉H₈NO⁽¹⁺⁾ 
• 109418-78-2 C₉H₈NS⁽¹⁺⁾ 
• 1724-43-2 cyclopropylium 
• 19469-08-0 cyclopropenyl cation 
• 20171-65-7 Cyclopentadien-1,3-yl-5 ion 
• 74-86-2 acetylene 

Relevant academic research and scientific papers

Time- and product-resolved photodissociations of bromotoluene radical cations

Photodissociations of o-, m-, and p-bromotoluene radical cations have been studied in the wavelength range 575-475 nm using Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometry. The parent ions were prepared by charge-transfer reactions of bromotoluenes with toluene-d8 radical cations produced by two-photon ionization of toluene-d8 at 266 nm. Bromotoluene radical cations dissociate to C7H7+ by loss of Br. The dissociation rates were measured by time-resolved photodissociation spectroscopy. Structures of C7H7+ from one-photon dissociation were identified by their bimolecular reactivities with toluene-d8. The C7H7+ products from all three isomers were identified as the benzyl cation. No unreactive tropylium ions were detected within experimental limits. The rate constants measured in this work were combined with the previous photoelcctron-photoion-coincidence results to refine activation parameters for the Rice-Ramsperger-Kassel-Marcus rate-energy curves, k(E), for the low barrier rearrangement process. The activation barriers are estimated to be 1.66, 1.80, and 1.78 eV for the o-, m-, and p-bromotoluene radical cations, respectively, whereas the entropy changes for the activation, ΔS?(1000 K), are -9.6, -7.2, and -5.6 eu., respectively. The mechanism of the rearrangement process is presented to account for the predominant formation of the benzyl cation.

Highly Selective Benzylic C-H Bond Activation of Toluene by 'Bare' FeO(1+) in the Gas Phase

The reaction of FeO(1+) with toluene in the gas phase occurs at collision rate (kr = 1.36*10-9 cm3 molecule-1 s-1), and labeling experiments demonstrate that the total products due to C-H bond activation involve to > 92percent the benzylic position.In the 'hydride' abstraction process (formation of FeOH and C7H7(1+)), the H-atom originates exclusively from the benzylic position to generate a benzyl cation, and an intramolecular kinetic isotope effect kH/kD = 1.75 has been obtained.There is no evidence for the existence of isotopically sensitive branching ('metabolic switching') in the system studied.

Identification of Chemi-ions Formed by Reactions of Deuterated Fuels in the Reflected Shock Zone

Dilute mixtures of various fuels with and without oxygen were analyzed dynamically from the reflected shock zone by time-of-flight mass spectrometry to test for the presence of chemi-ions.The identity of the major chemi-ion species and the amounts produced depended upon the fuel/O2 ratio, temperature, observation time, and the cleanliness of the shock tube-mass spectrometer system.Chemi-ions were readily observed in oxidative mixtures of acetylene, ethylene, benzene, and acetaldehyde.Deuterated compounds of these fuels were employed to demonstrate the absence of chemi-ions in oxygen-free mixtures.It follows that the radical-molecule mechanism for soot formation is dominant in pyrolytic reaction systems.

Carbocations generated under stable conditions by ionization of matrix-isolated radicals: The allyl and benzyl cations

Carbocations are crucial intermediates in many chemical reactions; hence, considerable effort has gone into investigating their structures and properties, for example, in superacids, in salts, or in the gas phase. However, studies of the vibrational structure of carbocations are not abundant, because their infrared spectra are difficult to obtain in superacids or salts (where furthermore the cations may be perturbed by counterions), and the generation of gas-phase carbocations in discharges usually produces several species. We have applied the technique of ionizing neutral compounds by X-irradiation of cryogenic Ar matrices to radicals embedded in such matrices, thus producing closed-shell cations that can be investigated leisurely, and in the absence of counterions or other perturbing effects, by various forms of spectroscopy. This Article describes the first set of results that were obtained by this approach, the IR spectra of the allyl and the benzyl cation. We use the information obtained in this way, together with previously obtained data, to assess the changes in chemical bonding between the allyl and benzyl radicals and cations, respectively.

Collisional stabilization and thermal dissociation of highly vibrationally excited C9H12+ ions from the reaction O 2+ + C9H12 → O2 + C9H12+

Highly vibrationally excited n-propylbenzene cations, C9H 12+*, were prepared by the charge transfer reaction O2+ + C9H12 → O2 + C9H12+* in a turbulent ion flow tube. The subsequent competition between fragmentation of C9H 12+* into C7H7+ + C2H5 and stabilization in collisions with N2 was studied at temperatures in the range 423-603 K and at pressures between 15 and 200 Torr. Most of the C7H7+ is the aromatic benzylium isomer, while the fraction of the minor species, seven-membered-ring tropylium, increases with T, from 5 to 20%. Minor fragments are C 6H6+, C7H8+, and C8H9+, Energy-transfer step sizes (ΔE) for collisional deactivation are obtained by combining the stabilization versus fragmentation ratios measured as a function of pressure in this study with fragmentation rates from the literature. The values are compared with related information for other excited molecular ions and are similar to those of their neutral analogues. At the highest temperatures, C 9H12+ was also observed to pyrolyze after collisional stabilization. Employing unimolecular rate theory, the derived rate constants for thermal dissociation of C9H12+ are related to values derived from the specific rate constants k(E,J) for fragmentation. Good agreement is found between measured and predicted pyrolysis rate constants. This allows us to confirm the dissociation energy of C 9H12+ into C7H7 + (benzylium) and C2H5 as 166.9 (±2.2) kJ mol-1 (at 0 K).

Dissociative proton transfer reactions of H3+, N2H+, and H3O+ with acyclic, cyclic, and aromatic hydrocarbons and nitrogen compounds, and astrochemical implications

A flowing afterglow-selected ion flow drift tube has been used to measure the rate coefficients and product ion distributions for reactions of H3O+, N2H+, and H3+ with a series of 16 alkanes, alkenes, alkynes, and aromatic hydrocarbons as well as acrylonitrile, pyrrole, and pyridine. Exothermic proton transfer generally occurs close to the collision rate. The reactions of H3O+ are mostly nondissociative and those of H3+ are mostly dissociative, but many reactions, especially those of N2H+, have both dissociative and nondissociative channels. The dissociative channels result mostly in H2 and/or CH4 loss in the small hydrocarbons and in toluene, loss of C2H2 from acrylonitrile, and loss of HCN from pyrrole. Only nondissociative proton transfer is observed with benzene, pyridine, and larger aromatics. Drift tube studies of N2H+ reactions with propene and propyne showed that increased energy in the reactant ion enhances fragmentation. Some D3+ reactions were also investigated and the results suggest that reactions of H3+ with unsaturated hydrocarbons B proceed through proton transfer that forms excited (BH+)* intermediates. Pressure effects suggest that a fraction of the (BH+)* intermediates decomposes too rapidly to allow collisional stabilization in the flow tube (t -8 s). The other low-energy (BH+)* intermediates are formed by the removal of up to 40% of the reaction exothermicity as translational energy, and these intermediates result in stable BH+ products. The results suggest that, in hydrogen-dominated planetary and interstellar environments, the reactions of H3+ can convert C2-C6 hydrocarbons to smaller and less saturated molecules, but polycyclic aromatics are stable against decomposition by this mechanism. The dissociative reactions of H3+ can therefore favor the accumulation of small unsaturated hydrocarbons and aromatics in astrochemical environments.

Mass-spectrometric study on ion-molecule reactions of CH5+, C2H5+, and C3H5+ with C9-C19 alkylbenzenes in an ion trap

Chemical ionization of alkylbenzenes (PhCxH2x + 1 = M: x = 3-13) by the CH5+, C2H5+, and C3H5+ ions has been studied under a reactant-ion selective mode of an ion-trap type of GC/MS. The dominant product ions for short-chain reagents (x +, [Phil + H]+, and CxH2x + 1+ ions, produced through proton-transfer to benzene ring. On the other hand, the dominant product ions for long-chain reagents (x ≥ 7) were CyH2y + 1+ (y yH2y+ (y ≤ x) ions. The former ions are produced through the attack of the reactant ions on the alkyl chain and/or the benzene ring, while the latter ones are exclusively formed through the attack of the reactant ions on the alkyl chain. Major formation processes of CyH2y + 1+ and PhCyH2y+ ions in each reaction were discussed on the basis of observed distributions and calculated thermochemical data.

Photodissociation dynamics of n-butylbenzene molecular ion

Photodissociation dynamics of n-butylbenzene molecular ion has been investigated on a nanosecond time scale. The rate constants for production of C7H8?+ and C7H7+, their branching ratios, and the kinetic energy release distributions have been determined by the photodissociation method using mass-analyzed ion kinetic energy spectrometry. The branching ratios have been found to be in excellent agreement with the previously established results. All the experimental data could be explained with statistical theories such as Rice-Ramsperger-Kassel-Marcus (RRKM) and phase space theories. RRKM fittings for these reactions have been improved. The present result supports the previous suggestion that the dissociation to C7H8?+ occurs via a stepwise McLafferty rearrangement.

Mass-Spectrometric Study on Ion-Molecule Reactions of CF3+ with Monosubstituted Benzenes Carrying a Hydroxy or Alkoxy Group at Near-Thermal Energies

The gas-phase ion-molecule reactions of CF3+ with monosubstituted benzenes carrying a hydroxy or alkoxy group [PhX: X=OH, CH2OH, CH2CH3OH, CH(OH)CH3, OCH3, and OC2H5] have been studied at near-thermal energies using an ion-beam apparatus. The major product channels are electrophilic addition on the O-atom, followed by loss of CF3OH, for ROH (R = Ph, PhCH2, PhCH2CH2, PhCHCH3); while they are electrophilic addition to a ring and a substituent, followed by molecular eliminations such as HF, C2H4, and PhF, for PhOCH3 and PhOC2H5. As a minor product channel, charge transfer is found for PhOH, PhOCH3, and PhOC2H5. The reaction mechanism is discussed based on product ion distributions and theoretical calculations of the potential energies of reaction pathways.

Threshold Formation of Benzylium (Bz+) and Tropylium (Tr+) from Toluene. Nonstatistical Behavior in Franck-Condon Gaps

Benzylium (Bz+) and tropylium (Tr+) ion formation from toluene-h8 and toluene-α-d3 were studied by time-resolved photoionization mass spectrometry (TPIMS).Bz+ was distinguished from Tr+ through its ion/molecule reaction with toluene, which converts it quantitatively to C8H9+.The appearance energies (AE's) at 0 K of C7H7+ without ion trapping (11.5 eV) and of Bz+ with ion trapping (11.1 eV) are in excellent agreement with predictions by time-resolved photodissociation (TRPD).The structure observed at photon energies below 11.1 eV in the Bz+ photoionization efficiency curve is ascribed to autoionizing Rydberg states converging to the third ionization energy in toluene.These states, which reside in a Franck-Condon gap, dissociate in competition with autoionization.This dissociation is a non-RRKM process forming Bz+, in preference to Tr+, and is made possible energetically by virtue of the thermal energy at the temperature of the experiment (298 K).H/D loss ratios for toluene-α-d3 demonstrate complete isotopic scrambling and an energy dependent isotope effect.The H/D ratio stays constant below 11.1 eV, demonstrating that AE0 K (Tr+) = 11.1 eV and that there is equality of the AE's of the two C7H7+ isomers within experimental error.The preferential, nonstatistical, formation of Bz+ over Tr+ below ca. 11.1 eV is given further proof by the observation of an increased direct CD2+ transfer probability from C6H5CD2+ to C6H5CD3.These results, combined with previously published ab initio calculations which demonstrated a reverse activation energy for the Tr+ exit channel, explain why there is no energy range in which there is pure Tr+ formation from toluene, under either photoionization or electron ionization conditions, although Tr+ is ca. 11 kcal/mol more stable than Bz+.