Theoretical Studies of Superalkalis Doping on Calix[4]arene; A Unique Approach for the Improvement of Nonlinear Optical Response

Abstract

Many scientists are interested in developing high-performance nonlinear materials because of their potential uses in areas such as optics, optoelectronics, optical computing, and others. Density Functional theory (DFT) is used to predict NLO response of the selected systems. The study revealed that the doping of superalkalis on calix[4]arene is an efficient strategy to design high performance NLO materials. The interaction energy (Eint) calculations are used to analyze the thermal stability of the complexes under consideration. Superalkali doping generates diffuse surplus electrons, which produce the alkalide properties in the corresponding systems. Through static and dynamic hyperpolarizability investigations, these alkalides are further studied for their nonlinear optical (NLO) responses. The large values of second (5.9×105) and third-order (1.9×108) NLO responses at 1200 nm, along with a high refractive index, demonstrate that the NLO response of the corresponding complexes increases at large wavelength. The nature of charge transfer was confirmed by the NBO analysis. The weak electrostatic interactions between calix[4]arene and superalkali was revealed through QTAIM and interaction region indicator analysis (IRI). The TD-DFT calculations confirmed the transparency of these superalkali (Li3O, Na3O and K3O) doped complexes in UV-VISIBLE regions. Overall, the study highlights the M3O@calix[4]arene as potential candidate for designing high performance NLO materials.