Femtosecond photoelectron spectroscopy of trans-stilbene above the reaction barrier

Influence of charge transfer on the isomerisation of stilbene derivatives for application in cancer therapy

“…Consistent with our experimental results, we were able to confirm that the absorption wavelength redshifts and the oscillator strength increase for molecules with larger charge-transfer character. Similar to the well-known photoisomerisation process of stilbene [18][19][20], one electron from the HOMO (with π bonding character with respect to 4 the vinyl C=C bond) is excited to the respective anti-bonding LUMO, reducing the C=C bond order and facilitating bond rotation in all combretastatins. However, we observed that the elongation of the central C=C bond on excitation was slightly larger for derivatives of low charge-transfer character, while the relaxation energies for the fluorescence from the S 1 surface to the ground state were higher.…”

Stilbenes Synthesis and Applications

“…Photoinduced gelation by stilbene oxalyl amide compounds was described (116). Femtosecond photoelectron spectroscopy was employed to study the excitation of trans-stilbene above the isomerization reaction barrier (117). Data on the temperature dependence of the azulene (I) effect on the Ph 2 CO sensitized photoisomerization of stilbenes in PhMe, C 6 H 6 , Me3COH, and MeCN were shown to be consistent with the formation of identical stilbene triplets from the two isomers (118).…”

Stilbene Photoisomerization

“…Time-dependent density functional theory (TD-DFT) calculations, together with simulations of the electron energy distribution, allowed to estimate selective photoelectron energies of the S 0 , S 1 , S 2 , and D 0 electronic states (Figure 3.3) [24].…”

“…Femtosecond photoelectron spectroscopy was employed to study the excitation of trans-stilbene above the isomerization reaction barrier [82]. Apart from the S 1 contribution, evidence of a second electronic state was found on the basis of two different transients measured across the photoelectron spectrum.…”