Synthesis and Characterization of Two‐Photon Chromophores Based on a Tetrasubstituted Tetraethynylethylene Scaffold

Abstract

A new series of model dye molecules composed of three multibranched analogues based on the tetrasubstituted tetraethynylethylene structural motif have been synthesized and experimentally shown to possess strong and widely dispersed two-photon absorption (2PA) in the near-IR region. It was found that the spectral position of the major 2PA band could be tuned by the electronic nature of the selected substitution units. The studied model fluorophores also exhibited fairly low photodegradation of their fluorescence intensity even under prolonged UV-light irradiation, which is beneficial for the development of fluorescence probes that are needed for long-term light exposure. Furthermore, representative chromophores were selected to demonstrate the power-control properties within the femtosecond and nanosecond time domains.

Synthesis of Bis(arylethynyl)pyrrolo[3,2‐b]pyrroles and Effect of Intramolecular Charge Transfer on Their Photophysical Behavior

“…This modular type of approach has been utilized to π‐expand various cores, such as anthracene, tetracenes, pentacene, pyrene, porphyrin, diketopyrrolopyrrole, benzobisoxazole, and many other heterocyclic systems . The presence of multiple arylethynyl substituents has a profound influence on the photophysical properties of these compounds, typically producing a substantial bathochromic shift in both absorption and emission as well as increasing the two‐photon absorption cross sections . This is especially true when electron‐rich and electron‐deficient chromophores are linked to form quadrupolar A–π–D–π–A structures .…”

The Synthesis and Photophysical Properties of Weakly Coupled Diketopyrrolopyrroles

“…After cooling to room temperature, solvent was evaporated and crude material was purified by flash column chromatography (silica gel, EtOAc/hexanes, 3:7) to give 35 mg (48%) of 5 as red shiny crystals. (13). Compound 12 (187 mg, 0.40 mmol), aryl bromide 7 (280 mg, 0.92 mmol), palladium (II) acetate (5.0 mg, 5 mol%), and potassium acetate (86 mg, 0.88 mmol) were placed in a dry, argon-purged Schlenk tube.…”

“…The following are available online. Figure S1: 1 H and 13 C-NMR spectral data for 4, Figure S2: 1 H and 13 C-NMR spectral data for 5, Figure S3: 1 H and 13 C-NMR spectral data for 7, Figure S4: 1 H and 13 C-NMR spectral data for 8, Figure S5: 1 H and 13 C-NMR spectral data for 10, Figure S6: 1 H and 13 C-NMR spectral data for 11, Figure S7: 1 H and 13 C-NMR spectral data for 13, Figure S8: 1…”

“…In the chemistry of dyes and pigments, systems with extended π-conjugation have prevailed in the literature for years [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. There is, however, an increased interest in weakly coupled systems containing multiple biaryl linkages [ 9 , 10 , 11 , 12 , 13 , 14 ]. Depending on the dihedral angle both in the ground and in the excited states, the magnitude of electronic communication varies, leading to large Stokes’ shifts and strong solvatochromism of fluorescence.…”

Combined experimental and theoretical study of one- and two-photon absorption properties of D–π–A–π–D type bis(carbazolylfluorenylethynyl) arene derivatives: Influence of aromatic acceptor bridge

“…(d) 2-methyl-3-butyn-2-ol (2 eq. ), 2 mol% Pd(PPh 3 ) 2 Cl 2 , 2 mol% CuI, toluene/Et 3 2.5.2. 2,5-Bis((7-(9H-carbazo-9-yl)-9,9-dihexyl-9H-fluoren-2-yl) ethynyl)thiophene (CF2)…”