Furan Fragmentation in the Gas Phase: New Insights from Statistical and Molecular Dynamics Calculations

Erdmann, Ewa; Łabuda, Marta; Aguirre, Néstor F.; Díaz‐Tendero, Sergio; Alcamı́, Manuel

doi:10.1021/acs.jpca.8b00881

Cited by 22 publications

(22 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The HC 3 S + cation is formed through a chain of numerous H-atom migration processes after the ring opening of chlorothiophene. These H atom migrations are similar to the migration in furan as reported by Erdmann et al45 There are at least three isomers which give rise to neutral CH 2 Cl and H − C=C=C=S + ion.…”

supporting

confidence: 88%

Ground‐state dissociation pathways for the molecular cation of 2‐chlorothiophene: A time‐of‐flight mass spectrometry and computational study

Upadhyaya

2019

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

Rationale Halogenated thiophenes are an important class of compounds mostly used in the synthesis of various materials, showing unusual electronic and optical properties. The Thiophene Ring Fragmentation (TRF) process is widely used in synthetic chemistry. In this study, the fragmentation pattern of the molecular cation of halogenated thiophene, namely, 2‐chlorothiophene, was monitored to establish its dissociation mechanism. Methods The molecular cation of 2‐chlorothiophene was prepared using multiphoton excitation using a laser at 235 nm. Various product ions upon fragmentation of the molecular ion were mass analyzed using time‐of‐flight mass spectrometry. Laser power dependence studies were also conducted for various product ions to arrive at the dissociation mechanism. Theoretical calculations were carried out to estimate the reaction enthalpies for various reactions and compared with the experimental data available in the literature. Results The most abundant product ion was observed as the HCS+ radical cation followed by the C3H3+ ion and the H2CCCCS+ radical cation. Other product ions such as SCCl+, ClHCCS+ radical cations were also observed to a lesser extent in the fragmentation pattern of the parent molecular ion. Various dissociation channels were identified and supported with ab initio calculation. It has been inferred that the TRF process is usually initiated by the H/Cl atom transfer process. The appearance energies of the various fragment ions were also estimated theoretically and compared with literature values. Conclusions In conclusion, the fragmentation pattern of the molecular cation of 2‐chlorothiophene was studied and the formation mechanisms of various product ions have been assigned. The appearance energies of the various fragment ions were also calculated. Finally, it is inferred that a TRF process is initiated by the H/Cl atom migration and subsequent ring opening either by C–C or C–S bond cleavage leading to the various isomers and their subsequent fragmentation. The ionization energies were accurately predicted for various species using ab initio calculation.

show abstract

supporting

confidence: 88%

Ground‐state dissociation pathways for the molecular cation of 2‐chlorothiophene: A time‐of‐flight mass spectrometry and computational study

Upadhyaya

2019

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

show abstract

“…However, a direct elimination of neutral H from C 4 H 4 O + cation has a low probability, because the mass spectra showed a surprisingly low relative abundance (below 1%) of the C 4 H 3 O + ion [31]. The newest theoretical investigation on neutral furan decomposition [33] showed that the skeleton fragmentation of furan has the lowest energy barrier, and it starts from the ring opening by cleavage of the weakest C−O bond followed by an isomerization and further breakage of the C−H, C−C, and/or C−O bonds. This scenario was indeed established in the experimental results.…”

Section: Resultsmentioning

confidence: 99%

“…It is also present as significant species in the pyrolysis of fossil fuels [17]. Thus ionization and fragmentation of this compound have been extensively studied by both experimental and theoretical approaches [18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33].…”

Section: Introductionmentioning

confidence: 99%

Charge Transfer, Complexes Formation and Furan Fragmentation Induced by Collisions with Low-Energy Helium Cations

Wąsowicz

Łabuda

Pranszke

2019

IJMS

Self Cite

View full text Add to dashboard Cite

The present work focuses on unraveling the collisional processes leading to the fragmentation of the gas-phase furan molecules under the He+ and He2+ cations impact in the energy range 5–2000 eV. The presence of different mechanisms was identified by the analysis of the optical fragmentation spectra measured using the collision-induced emission spectroscopy (CIES) in conjunction with the ab initio calculations. The measurements of the fragmentation spectra of furan were performed at the different kinetic energies of both cations. In consequence, several excited products were identified by their luminescence. Among them, the emission of helium atoms excited to the 1s4d 1D2, 3D1,2,3 states was recorded. The structure of the furan molecule lacks an He atom. Therefore, observation of its emission lines is spectroscopic evidence of an impact reaction occurring via relocation of the electronic charge between interacting entities. Moreover, the recorded spectra revealed significant variations of relative band intensities of the products along with the change of the projectile charge and its velocity. In particular, at lower velocities of He+, the relative cross-sections of dissociation products have prominent resonance-like maxima. In order to elucidate the experimental results, the calculations have been performed by using a high level of quantum chemistry methods. The calculations showed that in both impact systems two collisional processes preceded fragmentation. The first one is an electron transfer from furan molecules to cations that leads to the neutralization and further excitation of the cations. The second mechanism starts from the formation of the He−C4H4O+/2+ temporary clusters before decomposition, and it is responsible for the appearance of the narrow resonances in the relative cross-section curves.

show abstract

“…This can be veried from the points mentioned in other studies. 31 That is, the pyrolysis of furan rst forms an a-carbene structure or a b-carbene structure, owing which the ring opens; or H in the carbene structures break away rst to form the free radical structures, and then, the rings open. According to the population numbers of the three possible intermediates IM1, IM2, and IM3 generated aer the R1 ring opening, the population numbers between O5 and C1 are on average larger than those between C1 and C2.…”

Section: Structural Parameter Analysis Of Furan and Its Main Derivativesmentioning

confidence: 99%

“…Based on the research reported by Erdmann et al, 31 using the new modied function, three possible paths for furan pyrolysis via ring opening to generate CO were calculated and are presented in Fig. 2.…”

Section: Furan Pyrolysismentioning

confidence: 99%

Mechanistic investigation of CO generation by pyrolysis of furan and its main derivatives

et al. 2019

View full text Add to dashboard Cite

show abstract

Furan Fragmentation in the Gas Phase: New Insights from Statistical and Molecular Dynamics Calculations

Cited by 22 publications

References 63 publications

Ground‐state dissociation pathways for the molecular cation of 2‐chlorothiophene: A time‐of‐flight mass spectrometry and computational study

Ground‐state dissociation pathways for the molecular cation of 2‐chlorothiophene: A time‐of‐flight mass spectrometry and computational study

Charge Transfer, Complexes Formation and Furan Fragmentation Induced by Collisions with Low-Energy Helium Cations

Mechanistic investigation of CO generation by pyrolysis of furan and its main derivatives

Contact Info

Product

Resources

About