The synthesis and photo-physical properties of extended styryl fluorescent derivatives of N-ethyl carbazole

Push–pull fluorophores with viscosity dependent and aggregation induced emissions insensitive to polarity

“…1 H NMR and 13 C NMR spectra were measured on an Agilent 500 MHz NMR spectrometer with tetramethylsilane as the internal standard. The main curiosity of this work is to enhance the photophysical properties of previously reported extended styryls [12]. Cis-trans polarization may possible across the double bond of previously synthesized molecules as shown in Figure 4a.…”

“…The carbazole moiety being rigid with a donor-rigidised residue improves π-electron delocalization resulting in a better two-photon absorbing property [13]. The N-alkyl carbazole compounds show solid-state fluorescence with good photophysical properties, and electro-optical properties [12]. A wide variety of structural modifications on the donor, acceptor and π-conjugated moieties have been reported such as carbazole extended with thiazole or thiophene moieties [5].…”

“…The carbazole ring is having two electron rich active sites 3 and 6 positions with respect to the bridge nitrogen. The introduction of electron withdrawing groups at these position leads to intramolecular charge transfer [12]. The carbazole moiety being rigid with a donor-rigidised residue improves π-electron delocalization resulting in a better two-photon absorbing property [13].…”

“…HRMS: Calculated for C 48 H 40 N 11 O 2 S 2 [M+H] + 866.0258, found 866.1890. Design of extended styryl.>>In continuation of our previous work[12], we planned to synthesize novel highly conjugated symmetrical D-π-A (D-donor, A-acceptor) extended styryls with rigid structure exhibiting intramolecular charge transfer. Design of such extended styryls with introduction of the thiazole ring between the acceptor and donor for rigidity may lead to enhancement of photophysical properties(Figure 1).…”

Synthesis and Characterisation of Novel Thiophene Based Azomethine Polymers and Study of Their Liquid Crystalline, Electrochemical and Optoelectronic Properties

“…In a polar solvent such as DMF or DMSO, the emissive S 1 singlet state of the intramolecular charge transfer is strongly solvated, and its energy is therefore decreased. Consequently, the energy gap E(S 1 , S 2 ) is enlarged so that the coupling of the S 1 state directly to the ground state stays open, and intersystem crossing from the S 1 to the triplet (T) state is enhanced 22,23 . The solid-state fluorescence spectra of PTAZ3 and PTAZ4 films under 450 nm excitation are shown in Figure 7 c and d (PTAZ1 and PTAZ2 were not examined).…”