NLOphoric Triphenylamine Derived Donor‐π‐Acceptor‐π‐Donor Based Colorants: Synthesis, Spectroscopic, Density Functional Theory and Z‐scan Studies

Abstract

Three Donor-p-Acceptor-p-Donor type styryl dyes (5a-c) with different secondary donors are synthesized and characterized to study their nonlinear and linear optical properties. The structure-property relationships of the dyes are described in the light of systematic photophysical and theoretical investigations. The photophysical characteristics of 5a-c are influenced by the polarity of the medium, with an appreciable bathochromic shift in emission (5b = 81 nm) and large Stoke shifts (5b = 104-173 nm) in polar solvents. 5a-c showed intramolecular charge transfer characteristics recognized with the help of emission solvatochromism, solvent polarity graphs, natural bond orbital analysis and HOMO-LUMO energy difference. The optimized geometry and frontier molecular orbitals reveal that the electron donation takes place from secondary donors and not from a fixed donor (triphenylamine) which is more twisted. The nonlinear optical properties obtained using solvent induced spectral shift and computational methods are found within the limiting values. Z-scan results reveal saturable kind of behavior for 5a, 5b and 5c, whereas 5a and 5b show reverse saturable kind of behavior in acetone and ethanol and hence give optical limiting values. The two-photon absorption cross section described by two-level approximation is highest for 5b (251-300 GM).

N‐Ethyl Carbazole Derived D‐π‐A‐π‐D Based Fluorophores: Consolidated Spectroscopic, Viscosity and DFT Studies

“…More drastic effects for 5 c support the above hypothesis where planarization between julolidine and dicyano vinylene can smoothen CT. On comparing the synthesized fluorophores with the reported analogue 1 , it is observed that substituting different donors of varying donating strength at the opposite end of the fixed donor results in enhanced optical properties. Furthermore, when these fluorophores were compared with our previously reported fluorophores, having a similar structure but freely rotating/twisted triphenylamine as a fixed donor, the fluorophores from this work gave enhance optical properties . Thus, fluorophores with such a framework where one donor is fixed with a rigid group and varying D 2 with the different N‐substituents can lead to excellent push‐pull systems with enhance optical properties.…”

Amino-substituted-1,1-dicyano-2,4-diaryl-1,3-butadiene chromophores: Synthesis and photophysical properties

“…2-(1-(4-(diphenylamino)phenyl)ethylidene)malononitrile ( 2) [16]. A mixture of 1 (1 mmol) and malononitrile (1 mmol) in a NH 4 AcO/AcOH buffer 10 ml were irradiated in a microwave at 120°C, 300 W for 4 min.…”

“…The synthesis of compounds 3a-d is presented in Scheme 1. At the first step 1-(4-(diphenylamino)phenyl)ethan-1-one ( 1) was converted to 2-(1-(4-(diphenylamino)phenyl) ethylidene)malononitrile ( 2) in the presence of NH 4 OAc/AcOH using microwave irradiation (MWI) by improved synthetic methods with higher yield [16]. Final products (3a-d) were…”

“…Recently, such structures have been used for recognition of serum albumin in urine and imaging in living cells [15]. Sekar and coworkers have recently demonstrated that in case of substitution by two amino groups in para position of both phenyls in 1,1-dicyano-2,4-diphenyl-1,3-butadiene, the ICT occurs from the amino group of phenyl in C4 position to both cyano groups [16].…”

Improved photovoltaic performance of phosphonic acid‐based sensitized solar cells via an electron‐withdrawing moiety: A density of functional theory study

“…[12] To reduce the energy difference between the HOMO and LUMO of the sensitizers and enhance the performance of DSSCs, researchers introduced quadrupolar structures such as D-π-A-π-D and D-π-A-π-A [13][14][15][16] and the octapolar (D-π-) 3 A or (A-π-) 3 D, [17] resulting in structures that display a large band adsorption spectra. [18] As the sensitizer is vital in DSSC devices, anchoring plays an important role as the unit that ensures the binding of the sensitizer to the semiconductor surface. After cyanovinyl carboxylic acid, phosphonic acid is the mainly used anchor group in the field of organic electronics.…”