Are vinyl coupled furan derivatives better than vinyl coupled thiophene derivatives for optoelectronic applications? – Answers from DFT/TDDFT calculations

Nonlinear Optical and Spectroscopical Properties of Functionalized Oligoanilines

“…The largest β magnitudes for the derivatives of each PANI redox state are related to the smallest Δ H‐L values and the largest μ values. The strong dicyanovinyl acceptor contributes to increase the nonlinear response, as well as the ground state dipole moment value for various organic compounds according to the experimental and theoretical works [24,26,27,29] …”

“…Moreover, the acceptor group is linked to the aromatic ring at the end of the oligomer structure for the D ‐ A derivatives, as well as for the oligomers having only the A group (Figure 1). Some π‐conjugated systems with NLO properties containing the dicyanovinyl acceptor display very low energy transitions for the charge transfer processes, which contribute to optimize the nonlinear coefficients [23,26–29] …”

“…[17][18][19][20][21][22] The introduction of electron-donating (D) and/or electron-withdrawing (A) groups into the structure of an oligomer promotes a marked increase in the β nonlinear response. [17,[21][22][23][24][25][26][27][28][29] Multidisciplinary research groups have shown that some parameters, such as the molecular conformation, asymmetry, delocalisation, spin multiplicity and charge transfer (CT) processes, correlate with the nonlinear response of oligomeric derivatives. [17,[21][22][23][24][25][26][28][29][30] The enhanced nonlinear coefficients of second-order optical materials are required for all-optical switching and electro-modulation.…”

“…Density Functional Theory (DFT) methods have been employed to investigate the nonlinear optical properties of various classes of oligomers by considering both the computational time and accuracy. [19,24,[27][28][29][30] In the present work, some functionalized octamers of the PANI neutral forms, that is, the leucoemeraldine, emeraldine and pernigraniline (Figure 1), were theoretically studied at the PBE1PBE/6-31G** level. [31][32][33][34] The nonlinear optical (NLO) properties of the designed oligoanilines were calculated using the coupled perturbed Kohn-Sham (CPKS) approach, which is based on the finite field (FF) method.…”

Spectra, Electronic Structure of 2-Vinyl Naphthalene and Their Oligomeric Scaffold Models: A Quantum Chemical Investigation

“…In addition, the oligomers of 1 [2VN] has been designed with the substitution of various donor and acceptor moieties to find candidates which has lower band gap since it's an important attribute in optoelectronic materials. In our earlier work, we investigated the nature of band gap in vinyl substituted thiophene and furan derivatives computationally [9,10]. We observed that, the vinyl coupled furan oligomer tunes the optoelectronic properties to a great extent than the thiophene oligomers since they have lower band gap.…”