DFT investigation of M2F superalkali doped dodecafluorophenylene (C13H10F12) derivatives with remarkable static and dynamic NLO response

Abstract

Herein, based on density functional theory (DFT) simulations, the static and dynamic hyperpolarizabilities of the superalkalides based on Janus molecules have been explored. The designed superalkalides M2F(F)-DDFP-M2F(H) contain Janus based Dodecafluorophenylene (DDFP) molecule doped with superalkalis on both sides acting as both electron acceptors and donors. Thermodynamic stabilities are evident from the negative values of interaction energies, which are observed in the range of −2.96 eV to −3.63 eV. The maximum interaction energy (Eint) obtained is −3.63 eV for Li2F(F)-DDFP-Li2F(H) complex. The NBO (natural bond orbital) and FMO (frontier molecular orbital) analyses confirm the true superalkalide nature of the designed complexes. FMO analysis further reveals the reduction in energy gap E(H-L) from 10.43 eV (for bare DDFP) to 3.17 eV for the designed superalkalis. Furthermore, NLO response of the studied complexes reveals that the maximum values of polarizability (617 au) and hyperpolarizability are seen for Na2F(F)-DDFP-K2F(H) (4.25 × 104 au) complex, which confirms the remarkable NLO response of newly designed superalkalides. Moreover, frequency dependent analysis indicates that the maximum values of simple harmonic generation (SHG), electro-optical pockel effect (EOPE) and hyper Rayleigh scattering are 7.79 × 106, 2.75 × 106 and 4.45 × 106 au, respectively. The EOKE and EFISHG values are 6.79 × 107 and 7.68 × 1010 at 1339 nm suggesting significant increase in the NLO response of the reported complexes. These results manifest that our designed complexes might provide new paths towards the exceptionally high performance NLO materials. Moreover, we expect that the present work will provide guidance for designing and synthesis of superalkali based NLO materials in future.