848568-92-3Relevant academic research and scientific papers
Solvent and branching effect on the two-photon absorption properties of push-pull triphenylamine derivatives
Cvejn,Michail,Seintis,Klikar,Pytela,Mikysek,Almonasy,Ludwig,Giannetas,Fakis,Bure?
, p. 12819 - 12828 (2016)
The photophysical and two-photon absorption (2PA) properties of two tri-podal molecules and of their quadrupolar and dipolar counterparts are reported for a series of solvents with varying polarity. The molecules possess a tri-phenylamine electron donating group and mono-cyano acceptors while olefinic and acetylenic π-linkers have been used. Branching led to an increase of the molar extinction coefficient and to a slight bathochromic shift of the absorption spectra while the fluorescence quantum yields decrease but they are maintained to relatively high values. Solvatochromic measurements in the tri-podal molecules revealed an emitting state with a polar nature. The 2PA cross sections in general increase upon branching but the observed behaviour strongly depends on the type of solvent. The highest 2PA cross sections are obtained in solvents of medium polarity and values as high as 1420 GM are reported.
Modulation of (non)linear optical properties in tripodal molecules by variation of the peripheral cyano acceptor moieties and the π-spacer
Cvejn,Michail,Polyzos,Almonasy,Pytela,Klikar,Mikysek,Giannetas,Fakis,Bure
supporting information, p. 7345 - 7355 (2015/08/11)
A series of twelve tripodal push-pull molecules with a central triphenylamine donor and peripheral cyano substituted acceptors has been prepared. These molecules possess systematically altered π-linkers as well as cyano acceptors. Based on the experimental properties measured by differential scanning calorimetry, electrochemistry, one and two photon absorption/emission spectroscopy, supported by the DFT calculations, thorough structure-property relationships were elucidated.
Two-photon photosensitized production of singlet oxygen: Sensitizers with phenylene-ethynylene-based chromophores
McIlroy, Sean P.,Clo, Emiliano,Nikolajsen, Lars,Frederiksen, Peter K.,Nielsen, Christian B.,Mikkelsen, Kurt V.,Gothelf, Kurt V.,Ogilby, Peter R.
, p. 1134 - 1146 (2007/10/03)
(Chemical Equation Presented) Singlet molecular oxygen (a 1Δg) has been produced and optically monitored in time-resolved experiments upon nonlinear two-photon excitation of photosensitizers that contain triple bonds as an integral part of the chromophore. Both experiments and ab initio computations indicate that the photophysical properties of alkyne-containing sensitizers are similar to those in the alkene-containing analogues. Most importantly, however, in comparison to the analogue that contains double bonds, the sensitizer containing alkyne moieties is more stable against singlet-oxygen-mediated photooxygenation reactions. This increased stability can be advantageous, particularly with respect to two-photon singlet oxygen imaging experiments in which data are collected over comparatively long time periods.
