Photo-induced dynamics in a pyrene–isoalloxazine(flavin)–phenothiazine triad

Synthesis and Characterization of Electroactive Ferrocene Derivatives: Ferrocenylimidazoquinazoline as a Multichannel Chemosensor Selectively for Hg2+ and Pb2+ Ions in an Aqueous Environment

“…Among the compounds under study (H 2 O/EtOH; 1:1, v/v; c , 10 μM), 1 – 3 (λ ex is 325 nm for 1 and 320 nm for 2 and 3 ) exhibit weak fluorescence at ∼401–405 nm (500 V PMT; Figure b); however, 4 displays relatively high fluorescence at 427 nm (Φ, 0.26; pyrene; λ ex , 325 nm) . The cyclic compound 1 fluoresces weakly because of rupture of the electronic conjugation at chiral centers 2, 4, and 5, while Schiff bases 2 and 3 are due to the lack of planarity and the photoinduced electron-transfer process.…”

Photoinduced processes in macrocyclic isoalloxazine–anthracene systems

“…Blue-light excitation causes a small spectral red shift of the S 0 -S 1 absorption band due to protein-flavin hydrogen-bond rearrangement which is mediated by photoinduced reductive electron transfer from an adjacent tyrosine to the flavin [30]. This flavin cofactor photoexcitation leads to changes in redox and protonation states that ultimately rearrange protein conformation and change molecular interactions [31].…”

Ultrafast intramolecular electronic energy transfer in rigidly linked aminopyrenyl–aminobenzanthronyl dyads—a femtosecond study

“…[7][8][9][10][11] Following the discovery of pyrene excimer formation by Fo¨rster and Kasper, 12 pyrenyl groups have played a prominent role as chromophores in covalently linked systems to investigate the dynamics of exciplex formation and electron transfer [13][14][15][16][17][18][19][20][21][22] as well as intramolecular electronic excitation energy transfer (EET) in solution. [23][24][25][26] Recently, we reported on a donor-acceptor system consisting of a rigid s-triazine ring spacer (T) connecting an aminopyrene type donor unit (APy) and an aminobenzanthrone type acceptor unit (ABa), see Scheme 1. 27 Not unexpectedly for this comparatively rigid structure, 28,29 we found strong evidence that intramolecular EET from the initially excited APy donor to the ABa acceptor is extremely efficient and takes place on a B10 À13 s time scale.…”