Effects of cluster formation on spectra of benzo[a]pyrene and benzo[e]pyrene

Fioressi, Silvina E.; Binning, R. C.; Bacelo, Daniel E.

doi:10.1016/j.cplett.2008.02.007

Cited by 13 publications

(15 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experimentally, the most stable structures of clusters of large PAH were often reported to present stack patterns, sometime suggesting parallel displaced features, the presence of a molecule on a stack side [21,[37][38][39]. This is in line with theoretical calculations which investigated dimers at the ab inito level [30,[39][40][41][42][43][44][45][46][47][48] and larger clusters using force field or coarse grained models [9,19,30,[47][48][49][50][51] often combined with global exploration schemes. In order to characterize the stability of PAH clusters, their evolution after absorption of UV photons, collision with a low or high energetic particles or within a high pressure environment [52][53][54][55][56][57][58][59][60], were studied.…”

Section: Introductionsupporting

confidence: 56%

Thermal evaporation of pyrene clusters

Zamith

L'Hermite

et al. 2019

The Journal of Chemical Physics

View full text Add to dashboard Cite

This work presents a study of the thermal evaporation and stability of pyrene (C 16 H 10)n clusters. Thermal evaporation rates of positively charged mass-selected clusters are measured for sizes in the range n=3-40 pyrene units. The experimental setup consists of a gas aggregation source, a thermalization chamber and a time of flight mass spectrometer. A microcanonical Phase Space Theory (PST) simulation is used to determine the dissociation energies of pyrene clusters by fitting the experimental breakdown curves. Calculations using the Density Functional based Tight Binding combined with Configuration Interaction (CI-DFTB) model and a hierarchical optimization scheme are also performed in the range n=2-7 to determine the harmonic frequencies and a theoretical estimation of the dissociation energies. The frequencies are used in the calculations of the density of states needed in the PST simulations, assuming an extrapolation scheme for clusters larger than 7 units. Using the PST model with a minimal set of adjustable parameters, we obtain good fits of the experimental breakdown curves over the full studied size range. The approximations inherent to the PST simulation and the influence of the used parameters are carefully estimated. The derived dissociation energies show significant variations over the studied size range. Compared to neutral clusters, significantly higher values of the dissociation energies are obtained for the smaller sizes and attributed to charge resonance in line with CI-DFTB calculations.

show abstract

Section: Introductionsupporting

confidence: 56%

Thermal evaporation of pyrene clusters

Zamith

L'Hermite

et al. 2019

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…Spectroscopic studies of BaP monomer, dimer, and trimer had been done by Fioressi et al 36 BaP forms aggregates in aqueous media and is monodispersed in organic solvents. In a cell, as BaP prefers to partition into lipid droplets and the membrane portion, it is in a monomeric form.…”

Section: Resultsmentioning

confidence: 99%

Potential of Fluorescence Imaging Techniques To Monitor Mutagenic PAH Uptake by Microalga

Subashchandrabose

Krishnan

Gratton

et al. 2014

Environ. Sci. Technol.

View full text Add to dashboard Cite

Benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon (PAH), is one of the major environmental pollutants that causes mutagenesis and cancer. BaP has been shown to accumulate in phytoplankton and zooplankton. We have studied the localization and aggregation of BaP in Chlorella sp., a microalga that is one of the primary producers in the food chain, using fluorescence confocal microscopy and fluorescence lifetime imaging microscopy with the phasor approach to characterize the location and the aggregation of BaP in the cell. Our results show that BaP accumulates in the lipid bodies of Chlorella sp. and that there is Förster resonance energy transfer between BaP and photosystems of Chlorella sp., indicating the close proximity of the two molecular systems. The lifetime of BaP fluorescence was measured to be 14 ns in N,N-dimethylformamide, an average of 7 ns in Bold’s basal medium, and 8 ns in Chlorella cells. Number and brightness analysis suggests that BaP does not aggregate inside Chlorella sp. (average brightness = 5.330), while it aggregates in the supernatant. In Chlorella grown in sediments spiked with BaP, in 12 h the BaP uptake could be visualized using fluorescence microscopy.

show abstract

“…From the experimental side, many studies focused on the investigation of structural properties of these clusters at the most stable geometrical configurations [5,7,[16][17][18][19]. Their energetic properties such as ionisation potentials have been recorded [20] as well as their spectral properties [21][22][23][24]. The stability of PAH clusters has also been investigated from experiments following the evaporation of these clusters after absorption of a photon or a collision process [25][26][27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

“…From the theoretical side, the size of the systems limits the use of ab initio wave function methods to the investigation of properties of the smallest clusters, namely dimers [18,[37][38][39], whereas larger clusters can be addressed either at the DFT level or with more semiempirical schemes [2,5,18,23,38,[40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]. Many of these studies, focused on structural properties, evidence a stacking growth process in agreement with experimental results.…”

Section: Introductionmentioning

confidence: 99%

Dynamical simulation of collision-induced dissociation of pyrene dimer cation

2021

View full text Add to dashboard Cite

We report a theoretical investigation of the collision induced dissociation of pyrene dimer cation, as recently investigated in the experimental work by Zamith et al. (J. Chem. Phys. 153, 054311 (2020)). Molecular dynamics simulations using potential energies and forces computed at the self-consistent charge density functional based tight binding level were conducted for different collision energies between 2.5 and 30 eV. It appears that most of the dissociation occurs on a short timescale (less than 3 ps). The dynamical simulations allow to visualise the dissociation processes. At low collision energies, the dissociation cross section increases with collision energies whereas it remains almost constant for collision energies greater than 10-15 eV. The analysis of the kinetic energy partition is used to get insights into the collision/dissociation processes at the atomic scale. The simulated time of flight mass spectra of parent and dissociation products are obtained from the combination of molecular dynamics simulations and phase space theory to address the short and long timescales dissociation, respectively. The agreement between the simulated and measured mass spectra suggests that the main processes are captured by this approach.

show abstract

Effects of cluster formation on spectra of benzo[a]pyrene and benzo[e]pyrene

Cited by 13 publications

References 24 publications

Thermal evaporation of pyrene clusters

Thermal evaporation of pyrene clusters

Potential of Fluorescence Imaging Techniques To Monitor Mutagenic PAH Uptake by Microalga

Dynamical simulation of collision-induced dissociation of pyrene dimer cation

Contact Info

Product

Resources

About