Time-dependent mass spectra and breakdown graphs. 17. Naphthalene and phenanthrene

Gotkis, Yehiel; Oleinikova, Maria; Naor, Mor; Lifshitz, Chava

doi:10.1021/j100149a031

Cited by 102 publications

(131 citation statements)

References 6 publications

(7 reference statements)

Supporting

Mentioning

118

Contrasting

Order By: Relevance

“…In contrast, Jochims et al (1999) had observed in their experiments that the minimum photon energy causing the loss of a H atom by a photoionized PAH molecule was at least 2 eV lower when the molecule carried a methyl, a vinyl, or a phenyl group. Prior to the latter study, and Gotkis et al (1993) had found in TPIMS experiments that the minimum photon energy for H atom loss upon photoionization was also at least 2 eV lower in 1-and 2-methylnaphthalene than in naphthalene, for any time scale.…”

Section: Appearance Energiesmentioning

confidence: 91%

Dissociative Photoionization of Polycyclic Aromatic Hydrocarbon Molecules Carrying an Ethynyl Group

Rouillé

Krasnokutski

Fulvio

et al. 2015

ApJ

View full text Add to dashboard Cite

The life cycle of the population of interstellar polycyclic aromatic hydrocarbon (PAH) molecules depends partly on the photostability of the individual species. We have studied the dissociative photoionization of two ethynylsubstituted PAH species, namely, 9-ethynylphenanthrene and 1-ethynylpyrene. Their adiabatic ionization energy and the appearance energy of fragment ions have been measured with the photoelectron photoion coincidence spectroscopy technique. The adiabatic ionization energy has been found at 7.84 ± 0.02 eV for 9-ethynylphenanthrene and at 7.41 ± 0.02 eV for 1-ethynylpyrene. These values are similar to those determined for the corresponding non-substituted PAH molecules phenanthrene and pyrene. The appearance energy of the fragment ion indicative of the loss of a H atom following photoionization is also similar for either ethynyl-substituted PAH molecule and its non-substituted counterpart. The measurements are used to estimate the critical energy for the loss of a H atom by the PAH cations and the stability of ethynyl-substituted PAH molecules upon photoionization. We conclude that these PAH derivatives are as photostable as the non-substituted species in H I regions. If present in the interstellar medium, they may play an important role in the growth of interstellar PAH molecules.

show abstract

Section: Appearance Energiesmentioning

confidence: 91%

Dissociative Photoionization of Polycyclic Aromatic Hydrocarbon Molecules Carrying an Ethynyl Group

Rouillé

Krasnokutski

Fulvio

et al. 2015

ApJ

View full text Add to dashboard Cite

show abstract

“…1(e), where the subsequent dissociation step, 10 → C3, is much faster than the reverse reaction 10 → 6. [10] clearly stays at a steady state, with a slow formation and a fast decomposition, (k 16 + k −15 ) ≫ k 15 ( Fig. 1(e)).…”

Section: Fig 3 Ub3lyp/6-31g(dp)-optimized Geometries Of Selected Imentioning

confidence: 91%

“…9 Different mass spectrometry techniques have been used to study the energetics of the decompositions of the radical cation of naphthalene ([C 10 H 8 ] +• , m/z 128) and to shed light on the products. [10][11][12] Both collision-induced • ] + , it is usually assumed to be a direct C-H bond dissociation, either from the α-or β-positions of 1 (F4a, F4b), with a critical energy E 0 ranging from 4.20 to 4.48 eV.…”

Section: Introductionmentioning

confidence: 99%

A complete map of the ion chemistry of the naphthalene radical cation? DFT and RRKM modeling of a complex potential energy surface

Solano

Mayer

2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

A theoretical study of the reaction of O ( 3 P) with an allyl radical C 3 H 5 J. Chem. Phys. 119, 8966 (2003) The fragmentation mechanisms of the naphthalene molecular ion to [M-+ were obtained at the UB3LYP/6-311+G(3df,2p)//UB3LYP/6-31G(d) level of theory and were subsequently used to calculate the microcanonical rate constants, k(E)'s, for all the steps by the Rice-Ramsperger-Kassel-Marcus formalism. The pre-equilibrium and steady state approximations were applied on different regions of the potential energy profiles to obtain the fragmentation k(E)'s and calculate the relative abundances of the ions as a function of energy. These results reproduce acceptably well the imaging photoelectron-photoion coincidence spectra of naphthalene, in the photon-energy range 14.0-18.8 eV that was previously reported by our group. Prior to dissociation, the molecular ion rapidly equilibrates with a set of isomers that includes the Zand E-phenylvinylacetylene (PVA) radical cations. The naphthalene ion is the predominant isomer below 10 eV internal energy, with the other isomers remaining at steady state concentrations. Later on, new steady-state intermediates are formed, such as the azulene and 1-phenyl-butatriene radical cations. The naphthalene ion does not eject an H atom directly but eliminates an H 2 molecule in a two-step fragmentation. H• loss occurs instead from the 1-phenyl-butatriene ion. The PVA ions initiate the ejection of diacetylene (C 4 H 2 ) to yield the benzene radical cation. Acetylene elimination yields the pentalene cation at low energies (where it can account for 45.9%-100.0% of the rate constant of this channel), in a three-step mechanism starting from the azulene ion. However, above 7.6 eV, the major [M-C 2 H 2 ] +• structure is the phenylacetylene cation. C 2015 AIP Publishing LLC. [http://dx

show abstract

“…Our study focuses on the evaporation of H and H 2 , although other fragmentations could also occur, in particular loss of C 2 H 2 (Jochims et al 1992;Gotkis et al 1993;Granucci et al 1995).…”

Section: Theoretical Modelmentioning

confidence: 99%

Hydrogen dissociation of naphthalene cations: a theoretical study

Jolibois

Klotz

Gadéa

et al. 2005

A&A

View full text Add to dashboard Cite

show abstract

Time-dependent mass spectra and breakdown graphs. 17. Naphthalene and phenanthrene

Cited by 102 publications

References 6 publications

Dissociative Photoionization of Polycyclic Aromatic Hydrocarbon Molecules Carrying an Ethynyl Group

Dissociative Photoionization of Polycyclic Aromatic Hydrocarbon Molecules Carrying an Ethynyl Group

A complete map of the ion chemistry of the naphthalene radical cation? DFT and RRKM modeling of a complex potential energy surface

Hydrogen dissociation of naphthalene cations: a theoretical study

Contact Info

Product

Resources

About