Stacked dimer (C6H6F6)2 Janus based alkalides with ultraviolet transparency and remarkable NLO response

Abstract

The scientific community is constantly devoting efforts to investigate novel approaches for designing and producing materials possessing a large non-linear optical response. A successful idea is to design an excess electron system i.e., alkalide. Herein, we present alkalides based stacked dimer Janus molecule, SA′-2-M complexes (M = Li, K& Na and SA′ = Li₂F, K₂F, Na₂F &Li₃O, K₃O, Na₃O) using superalkali as an excess electrons’ source for alkali metals. The computed interaction energies corroborated the thermodynamic stability of the studied complexes. NBO charge transfer analysis as well as through HOMO(s) densities are used to corroborate the alkalide nature of the studied complexes. The density of HOMO is observed on the doped alkali metals i.e. Li, K or Na reflecting the alkalide nature. The absorption analysis indicates the transparency of studied M₂′F-2-M and M₃′O-2-M compounds in the ultraviolet region, indicating the maximum absorptivity (λ_max) in Vis and near IR regions of spectrum. The highest value of first hyperpolarizability (β_o) is calculated for the K₂′F-2-K (1.7 × 10⁶ au) and Na₃′O-2-K (4.5 × 10⁶ au) from M₂′F-2-M and M₃′O-2-M series, respectively. The high dc-Kerr effect values e.g., max ∼10⁹ and 10¹⁰ au for M₂′F-2-M and M₃′O-2-M series have been seen, respectively. These results imply that our studied complexes are designed with a new perspective on logical design of the stable materials with remarkable NLO response.