Enhanced nonlinearites of functionalized single wall carbon nanotubes with diethynylsilane derivatives

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] …”

“…It is worth mentioning that the chain conformations are affected by several factors, such as solvents, presence of a dopant and its chemical nature, and the molar ratio of the dopant in a sample. Hence, the conformation influences the distance of the delocalisation of charge‐carriers and in consequence electrical properties of the sample [27,44,54] . Consequently, the conformational distribution of each designed oligomer must be considered for a more realistic determination of absolute β hyperpolarizability.…”

“…Furthermore, several oligoanilines and hybrid materials containing aniline moieties show significant first ( β ) and second ( γ ) hyperpolarizabilities, as demonstrated by theoretical studies [17–22] . 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 [17,21–29] …”

“…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 [19,24,27–30] . 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 [31–34] .…”

“…[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.…”