Alkaline earth metals serving as source of excess electron for alkaline earth metals to impart large second and third order nonlinear optical response; a DFT study.

Continuous strides are made to explore new strategies for the design of materials with remarkable nonlinear optical response. Herein, we report the geometric, electronic, and nonlinear optical properties of novel bis-alkaline earth metal doped complexes of Janus all-cis-1,2,3,4,5,6-hexafluorocyclohexane F6C6H6 (1). These complexes contain unprecedented involvement of alkaline earth metals as sources of excess electron for the 2nd alkaline earth metal atom in the complex. Geometric electronic and thermodynamic properties of studied complexes AE-1-AE (where AE = Be, Mg, Ca) are obtained at M06-2X/6-31+G(d,p) level of theory. The NBO analysis is performed to predict the charge transfer. Moreover, the excess electron nature of these complexes is validated through frontier molecular orbital (FMOs) analysis. The PDOS and TDOS analysis are also performed to further rationalize the electronic properties. The remarkable static first hyperpolarizability (β0) and second hyperpolarizability (γ0) response up to 2.91 × 104 au and 4.08 × 106 au, respectively, are recorded for these complexes. Furthermore, the two-level model is also employed to get a comprehensive picture of the controlling factors for hyperpolarizability. Moreover, to get nonlinearity response from the experimental point of view, hyper Rayleigh scattering (βHRS) has been calculated and the highest value of 7.38 × 103 au is noticed for the complex I (Ca-1-Ca). These compounds besides providing a new entry into excess electron compounds will also pave the path for designing and synthesis of further novel NLO materials.