Enhanced nonlinear optical response of alkalides based on stacked Janus all- cis-1,2,3,4,5,6-hexafluorocyclohexane

Muhammad Sohaib; Hasnain Sajid; Sehrish Sarfaraz; Malai Haniti Sheikh Abdul Hamid; Mazhar Amjad Gilani; Muhammad Ans; Tariq Mahmood; Shabbir Muhammad; Mohammed A Alkhalifah; Nadeem S Sheikh; Khurshid Ayub

doi:10.1016/j.heliyon.2023.e19325

Enhanced nonlinear optical response of alkalides based on stacked Janus all- cis-1,2,3,4,5,6-hexafluorocyclohexane

Heliyon. 2023 Aug 19;9(9):e19325. doi: 10.1016/j.heliyon.2023.e19325. eCollection 2023 Sep.

Affiliations

¹ Department of Chemistry, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, KPK, 22060, Pakistan.
² School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK.
³ Chemical Sciences, Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE1410, Brunei Darussalam.
⁴ Department of Chemistry, COMSATS University Islamabad, Lahore Campus, Lahore-54600, Pakistan.
⁵ Department of Chemistry, University of Agriculture, Faisalabad, Punjab, Pakistan.
⁶ Department of Chemistry, College of Science, University of Bahrain, P. O. Box 32038, Bahrain.
⁷ Department of Chemistry, College of Science, King Khalid University, Abha, Saudi Arabia.
⁸ Department of Chemistry, College of Science, King Faisal University, Al-Ahsa 31982, Saudi Arabia.

Abstract

Significant efforts are continuously exerted by the scientific community to explore new strategies to design materials with high nonlinear optical responses. An effective approach is to design alkalides based on Janus molecules. Herein, we present a new approach to remarkably boost the NLO response of alkalides by stacking the Janus molecules. Alkalides based on stacked Janus molecule, M-n-M' (where n = 2 & 3 while M and M' are Li/Na/K) are studied for structural, energetic, electrical, and nonlinear optical properties. The thermodynamic stability of the designed complexes is confirmed by the energetic stabilities, which range between -14.07 and -28.77 kcal/mol. The alkalide character of alkali metals-doped complexes is confirmed by the NBO charge transfer and HOMO(s) densities. The HOMO densities are located on the doped alkali metal atoms, indicating their alkalide character. The absorptions in UV-Vis and near IR region confirm the deep ultraviolet transparency of the designed complexes. The maximum first static and dynamic hyperpolarizabilities of 5.13 × 10⁷ and 6.6 × 10⁶ au (at 1339 nm) confirm their high NLO response, especially for K-2-M' complexes. The NLO response of alkalides based on stacked Janus molecules is 1-2 orders of magnitude higher than the alkalide based on Janus monomer. The high values of dc-Kerr and electric field-induced response e.g., max ∼10⁷ and 10⁸ au, respectively have been obtained. These findings suggest that our designed complexes envision a new insight into the rational design of stable high NLO performance materials.

Keywords: Alkalides; Density functional theory; Janus molecule; NLO response; Stacking.