Triphenylamino α‐Cyanovinyl‐ and Cyanoaryl‐Based Fluorophores: Solvatochromism, Aggregation‐Induced Emission and Electrochemical Properties

Abstract

As eries of linear,V -shaped and branched triphenylamine/tris(biphenyl)amine-based derivatives with electron-withdrawing cyanovinyl-and phenyl-substituted conjugated branches containing either electron-donatingO Me or electron-withdrawing CN end groups have been synthesized. UV/vis absorption and fluorescencee mission data illustrates that introductiono ft he electron-donor/acceptorg roups induces intramolecular charget ransfer that leads to as hift of the absorption onset towardl ongerw avelengths. Addition of large amounts of water to solutions of triphenylamine derivative caused their emission to reach maximal intensitythese molecules all undergo aggregation-induced emission; this was confirmed by aggregation studies. All the compoundsi nt his study present ar eversible first oxidation process, the potential of which increases with the number of electron-withdrawing groups in the molecules, as was confirmed by cyclic voltammetry.F urthermore, the influence of solventp olarity on the photophysical properties was investigated. All the triphenylamine derivatives exhibit intensive intramolecular charge-transfer interactions, giving rise to asubstantiale xtension of their absorption spectral response, which might be potentially used in efficient organic solar cells.[a] R.Synthesized according to general procedure Cu sing 10 (0.5 g, 0.9 mmol) and 4-cyanobenzyl cyanide (0.14 g, 1.0 mmol) to give ar ed-orange powder (80 %y ield);m .p. 182-184 8C; 1 HNMR (300 MHz, CDCl 3 ): d = 10.06 (s, 1H), 8.03 (d, J = 8.4 Hz, 4H), 7.96 (d, J = 8.1 Hz, 2H), 7.81 (m, 5H), 7.74 (m, 10 H), 7.66 (s, 2H), 7.63 (d, J = 8.4 Hz, 6H), 7.29 ppm (d, J = 8.1 Hz, 4H); 13 CNMR (75 MHz, CDCl 3 ):

Novel Ferrocene‐Appended β‐Ketoimines and Related BF2 Derivatives with Significant Aggregation‐Induced Emission and Second‐Order Nonlinear Optical Properties

“…The changes in the wavelength maxima ( λ max ) of the β‐ketoimines with solvent polarity were compared with the α (hydrogen‐bond donor), β (hydrogen‐bond acceptor), and π * (polarizability) solvent parameters, as determined by Kamlet and Taft (see Table S4 in the Supporting Information) [55] . An increase in the solvent polarity from THF to DMSO revealed positive solvatochromism of the absorption spectra of the β‐ketoimines with a redshift of λ max of 51 ( L1 ), 61 ( L2 ), 52 ( L3 ), and 37 ( L4) nm (see Figures S47–S50), which indicates that polar solvents can lead to better stabilization of a polarized excited state, arising from extended intramolecular charge transfer (ICT) from the ferrocenyl donor to the acceptor moieties [56] . The redshift of the λ max values with increasing solvent polarity reveals an increase in the dipole moment upon excitation, in agreement with the results of TD‐DFT calculations (Table 2), which predicted that the excited states of these β‐ketoimines should be more polar than the ground states [57] …”

Synthesis of C3-Symmetric Triazine-Based Derivatives: Study of their AIEE, Mechanochromic Behaviors, and Detection of Picric Acid and Uric Acid in Aqueous Medium

“…Hereafter, the polarized excited state is stabilized to suit the enhanced dipole moment through the relocation of the polar solvent molecules, resulting in the observed red-shifted emission maximum and thereby lowering of the energy. A Dimroth–Reichard solvent polarity correlations plot − of TZOME, TZSET, and TZNET (Figures S27–S29) shows higher values of Stokes shift on moving from nonpolar to polar solvents; hence, we observed a large charge separation, higher dipole moment in the excited state, and higher intramolecular charge transfer in the excited state when compared to the ground state. Then, we investigated the electronic and geometric properties of all of the triazine-based materials and optimized their quantum calculations by time-dependent density functional theory (TDDFT) calculations at CAM-B3LYP/6-31G (d, p) in the Gaussian 09 program. − The distribution of electrons in the HOMO and LUMO of TZOME, TZSET (Figure S30), and TZNET is shown in Figure S31.…”

Novel star-shaped D–π–D–π–D and (D–π)2–D–(π–D)2 anthracene-based hole transporting materials for perovskite solar cells

“… 21 Compound 3 was synthesized by the same procedure as described for the synthesis of compound 2 except that compounds 1-bromo-4-methoxybenzene (2 g, 10.75 mmol) and 4-methoxyaniline (1.45 g, 11.8 mmol) were used. 22 To a stirred solution of compound 2, 4-(bis(4-(bis(4-methoxyphenyl)amino) phenyl)amino)benzaldehyde (0.2 g, 0.482 mmol) and methyltriphenylphosphonium iodide (0.5 g, 1.272 mmol) were dissolved in DCM in a 100 mL round bottom flask, maintained under ice cold conditions. Furthermore, potassium tert -butoxide (0.2 g, 1.685 mmol) was portion wise added to the reaction mixture.…”