Janus alkaline earthides with excellent NLO response from sodium and potassium as source of excess electrons; a first principles study

• Published in: Journal of molecular graphics & modelling 2020-11, Vol.100, p.107668-107668, Article 107668
• Main Authors: Sajjad, Saira, Ali, Akhtar, Mahmood, Tariq, Ayub, Khurshid
• Format: Article
• Language: English
• Subjects: Alkaline earthides; Electronic stability; Nonlinear optical response; Two level model
• ISSN: 1093-3263; 1873-4243
• DOI: 10.1016/j.jmgm.2020.107668

Alkaline earthide is a well-known class of the excess electron compounds with potential applications as NLO materials. In this study, all-cis-1,2,3,4,5,6-hexafluor-ocyclohexane C6H6F6 (1), a high polarized complexant having the largest dipole moment (6.2D) among all the known aliphatic hydrocarbons, is selected as a suitable molecule for designing a new series of excess electron molecules, alkaline-earthides. Geometric, thermodynamic and electronic properties of A-1-AE (A = Li, Na, K and AE = Be, Mg, Ca) are studied at M06-2X/6-31+G(d,p) level of theory. More specifically, alkaline-earthide nature is confirmed by distribution of densities in HOMOs, VIE values and NBO analysis. The alkaline earthide possess moderate complexation energies (−6.56 to −14.19 kcal/mol), which demonstrate their thermodynamic stability. These alkaline earthides possess very small excitation energies (0.54–1.64 eV) and very large first hyperpolarizabilities (up to 4.14 × 109 au). The higher hyperpolarizabilities values are attributed to the presence of excess electrons on alkaline earth metals which is confirmed through the partial density of states (PDOS) analysis. The hyperpolarizabilities are rationalized through two level model approach. Large hyperpolarizability values illustrate that the alkaline-earthides are a very promising entry into excess electron compounds. Alkaline earthide based on Janus-all-cis 1, 2, 3, 4, 5, 6-hexaflorocyclohexane. [Display omitted] •A new series of alkaline earthides have been designed.•These are thermodynamically stable with interaction energies up to −14.19 kcal/mol.•Exceptionally high first hyperpolarizabilities (βo) up to 4.14 × 109 au are observed.