Indolo[3,2‐b]carbazole‐based poly(arylene ethynylene)s through Sonogashira coupling for optoelectronic and sensing applications

Abstract

Two indolo[3,2-b]carbazole (ICZ)-based polymers have been designed and synthesized using Sonogashira cross-coupling based on dibromoindolo[3,2-b]carbazoles and 2,7-diethynylfluorene or 9,10-diethynylanthracene. The 2, 8 positions of the ICZ moiety has been used for the bridging of arylene ethynylene structure to form the polymer backbone. The characterization has been done by Fourier transform infrared, proton nuclear magnetic resonance, ultraviolet-visible and (UV-vis) fluorescence spectroscopic methods. The polymers, moderately soluble in aprotic and chlorinated solvents, have been found to possess thermal stability above 300 C. The band gap examinations, executed through cyclic voltammetry and complemented by UV-vis studies, indicated their semiconducting nature and the possibility for their utilization for the fabrication of polymer solar cells and for optical switching applications. Interestingly, the new diethynylindolocarbazole systems have been found to act as Bronsted acid sensors as well as a Hg 2+ receptors.

Facile synthesis and exploration of excited state assisted two-photon absorption properties of D–A–D type thiophene–pyridine derivatives

“…For instance, Gopi et al 28 synthesized a new solution processable quinoxaline based push-pull molecule with 3-ethyl rhodanine as an acceptor unit and investigated the NLO properties of the molecule, which showed an effective TPA with the β eff value as high as 10.0 × 10 −10 m W −1 with a LT of 2.46 J cm −2 . Vintu et al 29 synthesized a novel anthracene supported 5,11-dihydroindolo [3,2-b] carbazole-based polymer for nonlinear optical applications, which showed a very high β eff value of 11.6 × 10 −10 m W −1 with a LT of 1.03 J cm −2 . Zawadzka et al 30 synthesized two 5,10-A 2 B 2 porphyrin series with different metals in the core and investigated the NLO properties, and with the tin(IV) complex, SnCl 2 _CCTMS, porphyrin showed RSA with a β eff value of 6.4 × 10 −10 m W −1 .…”

Sequential One‐Pot Process to Construct a Dual C−C Bond: Synthesis of Fluorenes and Total Synthesis of 4‐O‐Demethyl‐nobilone

“…In the 1 H NMR, the following abbreviations were used: s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet and brs = broad singlet. The assignment of signals was confirmed by 1 H, 13 C{ 1 H}, and DEPT spectra. Benzaldehydes, aryl halides, alkyl halides and Mg metal, Pd(OAc) 2 , PPh 3 , Cs 2 CO 3 , phenylboronic acids, Na 2 SO 4, and NH 4 Cl, were commercially available and used without further purification.…”

“…1 H NMR spectra were recorded on 400 and 600 MHz spectrometers at 295 K in CDCl 3 ; chemical shifts (δ ppm) and coupling constants (Hz) were reported in a standard fashion regarding either internal standard tetramethylsilane (TMS) (δH = 0.00 ppm). 13 C{ 1 H} NMR spectra were recorded on 100 and 150 MHz spectrometers at 295 K in CDCl 3 ; chemical shifts (δ ppm) were reported relative to CHCl 3 [δC = 77.00 ppm (central line of the triplet)]. In the 13 C{ 1 H} NMR, the nature of carbons (C, CH, CH 2 , and CH 3 ) was determined by recording the DEPT-135 spectra and is given in parentheses and noted as s = singlet (for C), d = doublet (for CH), t = triplet (for CH 2 ) and q = quartet (for CH 3 ).…”

“…[11] Recently, in 2021, 4-O-demethyl-nobilone was extracted from the aerial parts of Dendrobium nobile Lindl. [3] Fluorene derivatives have also been known for their significant applications in material science, particularly in organic materials, including optoelectronics, [12,13] and organic semiconductors. [14][15][16] For instance, poly(fluorene), [17] acts as a material of organic light emitting diodes (OLEDs) (Figure 1).…”

Pd-Catalyzed Cross-Couplings: On the Importance of the Catalyst Quantity Descriptors, mol % and ppm

“…Our analysis bares similar trends to Kumada–Corriu and Negishi cross-coupling reactions in that there is a greater use (52% of the data) of lower mol % values. From the journal articles examined (44 articles and 55 reactions, Figure ), ,− almost a third of the reactions make use of 1–2 mol % Pd catalyst with 25% employing 1 mol % or lower. The Sonogashira reaction shows a trend toward lower ppm values, typically in the 500 ppm and lower region (median value of 360 ppm).…”