Solvent Effects on the Two-Photon Absorption of Distyrylbenzene Chromophores

Abstract

A series of organic- and water-soluble distyrylbenzene-based two-photon absorption (TPA) fluorophores containing dialkylamino donor groups at the termini was designed, synthesized, and characterized. The central core was systematically substituted to modulate intramolecular charge transfer (ICT). These molecules allow an examination of solvent effects on the TPA cross section (delta) and on the TPA action cross section. In toluene, the delta values follow the order of ICT strength. The effect of solvent on delta is nonmonotonic: maximum delta was measured in an intermediate polarity solvent (THF) and was lowest in water. We failed to find a correlation between the observed solvent effect and previous theoretical predictions. Hydrogen bonding to the donor groups and aggregation of the optical units in water, which are not included in calculational analysis, may be responsible for the discrepancies between experimental results and theory.

A phenol-based compartmental ligand as a potential chemosensor for zinc(ii) cations

“…As Figure 8 shows, the fluorescence of L decreases remarkably with the increase of polarity and acidity in polar protic solvents. For example, the fluorescence is almost completely quenched in water in the absence or presence of Zn 2+ , which is similar to some reported chemosensors, 23,26 however, the fluorescence is enhanced by ca. 3 times in methanol and ethanol in the presence of Zn 2+ with red shifts of 11.5 and 19 nm for the maximum emission, respectively.…”

“…23 Therefore, L may form hydrogen bonds with H + , OH -and/or H 2 O in solution; L may also form intra-or intermolecular hydrogen bonds via its three phenolic and two alcoholic hydroxyl groups. Such hydrogen bonds can enhance the rigidity of L and thereby contribute to the moderate fluorescence of L in solution.…”

“…Polar protic solvents may act as carriers to facilitate the electron transfer through the partialpositively charged H-end. 23 Thus, the electron transfer process from the tertiary amino N to the phenolic moiety is accelerated and the fluorescence is quenched. Moreover, polar protic solvents may facilitate L to form intra-and intermolecular hydrogen bonds.…”

Oligopolyphenylenevinylene-Conjugated Oligoelectrolyte Membrane Insertion Molecules Selectively Disrupt Cell Envelopes of Gram-Positive Bacteria

“…DSSNϩ, 1,4-bis(4Љ-(N,N-bis(6ЉЉ-(N,N,N-trimethylammonium)hexyl)amino)-styryl)benzene tetraiodide (DSBNϩ), and 1,4-bis(4Љ-(N,N-bis(6ЉЉ-(N,N,N-trimethylammonium)hexyl)amino)-styryl)-2,3,5,6 tetrafluorobenzene tetraiodide (4F-DSBNϩ) were synthesized as reported previously (2,11). The MIMs used in this study were selected because their biotechnological potential had been demonstrated previously in bioelectrochemical systems and because interesting interactions with microbial cells have been documented (1,3,10).…”

Enhanced Two‐Photon Absorption of Organic Chromophores: Theoretical and Experimental Assessments

“…Thereby, attention has progressively moved from the well-known push-pull dipolar molecular structures [34,41,[75][76][77][78][79][80][81][82][83][84][85][86][87][88] to quadrupoles [3,33,36,57,58,63,76,78,81,85,86,[89][90][91][92][93][94][95][96][97][98][99][100][101][102][103][104][105][106][107] and, more recently, toward complex molecular architectures. Quadrupoles have been found to be more efficient than dipoles in terms of TPA, in particular for multiphoton-based opticallimiting applications.…”