Effect on nonlinear optical behaviors of p-butoxybenzylidene p-heptylaniline (BBHA) liquid crystal after doping of superhalogen (BO2) n, n = 1–2, by using density functional theory

The BBHA (p-butoxybenzylidene p-heptylaniline) is a Schiff base produced via the condensation process of p-butoxybenzaldehyde and p-heptylaniline. It has a negative anisotropic dielectric constant, which improves display modes at lower working voltages. Substitution of an electronegative element improves the liquid crystal's nonlinear optical performance. BO 2 is a superhalogen with stronger electronegativity than other halogens. In this communication, all calculations of BBHA and its mono- and di-substituted superhalogen species, BO 2 , on the substituted H of the phenyl ring of BBHA were performed using a combination of DFT/B3LYP approach using a 6–311 + +G(d, p) basis set. The estimated L/B ratio dihedral angle ovality (O) of BBHA and BBHA(BO 2 ) n for n = 1–2 demonstrates that, while some considerable deformation occurs, the geometry of BBHA does not vary from rod shape following mono and di substitution of BO 2 on BBHA. The quadrupole moment (TQ) trace shows how electrooptical properties change upon mono- or di-substitution of BO 2 in BBHA. The optical activity (AQ) characteristics of BBHA and BBHA(BO 2 ) n (n = 1–2) rise monotonically as the superhalogen BO 2 is mono- and di-substituted into BBHA. The NBO analysis demonstrates that charge transfer from the phenyl ring to superhalogen BO 2 stabilizes BBHA(BO 2 ) n for n = 1–2, which improves BBHA's nonlinear optical behavior following di-substitution with superhalogen BO 2 . The electronic characteristics of BBHA, BBHA(BO 2 ) n for n = 1–2, are calculated using the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and density of states (DOS) plot. The energy gap between HOMO and LUMO indicates chemical reactivity, which decreases with mono and di substitution of superhalogen BO 2 on BBHA. The polarity emerges as a result of the substitution of superhalogen BO 2 , which requires less energy to convert an electron from HOMO to LUMO. The delocalization of charge throughout the entire molecule caused by the substitution of superhalogen BO 2 improves the hyperpolarizability of BBHA(BO 2 ) n for n = 2. The production of mono and di-substituted BBHA is thermodynamically advantageous in the forward direction. Pure BBHA, a well-known liquid crystal, is contrasted with the nonlinear optical behavior of mono and di-substituted superhalogen BO 2 on BBHA. The kinetic stability of mono- and di-substituted superhalogen BO 2 on the BBHA was studied using ab initio molecular dynamics simulations. In this approach, the current study demonstrates that mono- and di-substituted BBHA are unique liquid-crystalline molecules that can be used at ambient temperature.