Interaction of low-energy electrons with linear diphenylethynyl derivatives in the gas phase

Abstract

We report calculated cross sections for elastic and inelastic collisions of low-energy electrons with tetrafluoroethene, C 2 F 4. The elastic cross section shows a number of resonance features, which we classify according to symmetry and analyze in relation to available experimental data. Electron-impact excitation cross sections are obtained for the 1 3 B 1u (T) and 1 1 B 1u (V) states arising from the →* transition, as well as for eight other low-lying excited states arising from excitations out of the highest occupied molecular orbital. As expected, the T and V states make the largest individual contributions to electron-impact excitation at low energies; however, the other states are shown to contribute significantly to the total excitation cross section at impact energies from 10 to 25 eV.

Photophysics and photostability of 9,10-bis(phenylethynyl)anthracene revealed by single-molecule spectroscopy

“…This theoretical approach has been previously reported to reproduce well the experimental electronic excitation energies of BPEA. 9 The geometry optimization for the lowest singlet excited state (S 1 ) was also conducted at a time-dependent Hatree-Fock (TD-HF)/6-31G(d) level with no symmetry constraint. 70 Harmonic vibrational frequencies of the optimized geometries for S 0 and S 1 states were also calculated to ensure that they represented true potential minima.…”

“…Accordingly, BPEA has been widely used as a molecular probe in various spectroscopic studies, [1][2][3][4][5][6][7] and its photophysical properties have been studied by a number of spectroscopic methods. [8][9][10][11][12] BPEA and its derivatives have been recently demonstrated to possess attractive optical and electronic properties, thereby making them promising candidates for a wide variety of optoelectronic and photonic applications such as lightemitting diodes, 13 photoswitches, 14 chemiluminescent light sources, 15 optical waveguides, 16 and solar cells. 17 Moreover, bis(arylethynyl)arene compounds have recently received considerable attention as molecular wires.…”

“…Photophysical parameters of BPEA, obtained via the singlet manifold (e.g., fluorescent quantum yield, W f , and fluorescence lifetime, t f ), have been widely reported in the literature. 8,12,[19][20][21] In contrast, few experimental efforts have been hitherto invested in the study of photophysics involving the triplet manifold of BPEA 9 whose W f value (ca. 1) prevents information about the triplet state from being obtained by conventional spin resonance and thermal lensing techniques.…”

Electric Field Oriented Nanostructured Organic Thin Films with Polarized Luminescence

“…Before the deposition, all substrates were carefully cleaned with ethanol. The thermal stability of M1 and M2 under evaporation is known to be high [14]; therefore, both compounds are capable to be deposited by thermal evaporation from solid.…”

Ionization of 4,4′-Bis(Phenylethynyl)-Anthracene by Electron Impact

“…13,14 BPEA molecules have been studied by low energy electron spectroscopy in the gas phase. 15 Mass spectroscopic information about fragmentation, dissociation, ionization potential and thermodynamic characteristics is absent, even in the known NISt database. 16…”