First-order molecular hyperpolarizability of xanthoangelol derivatives

This study explores the dynamic first-order molecular hyperpolarizability (\({\beta }_{2\omega }\)) of eight xanthoangelol (XAG) derivatives divided into two series. The first includes four XAG-based compounds previously synthesized and reported in the literature (XAG, XAG-B, XAG-I, and XAG-J), while the second comprises four novel, theoretically designed derivatives (XAG-C1, -C2, -P1, and -P2). These new structures enhanced π-conjugation along the prenyl (P) and chalcone (C) chains, improving the \({\beta }_{2\omega }\) response. Quantum-chemical calculations (QCC) were performed at three key operational wavelengths, 1064 nm, 1310 nm, and 1550 nm, relevant to laser applications and optical communications. The \({\beta }_{2\omega }\) values were computed under solvent conditions using five levels of theory (HF, B3LYP, CAM-B3LYP, M06-2X, and ωB97Xd) and 21 Pople-type basis sets, ranging from less robust (6-311G) to more advanced (6–311 +  + G(2d,2p)). Computational cost was also evaluated to guide future modeling efforts. Compared to potassium dihydrogen phosphate (KDP), a standard reference in nonlinear optical (NLO) materials, all XAG derivatives exhibited significantly enhanced \({\beta }_{2\omega }\) responses. XAG-C2 showed the highest value at 1064 nm, reaching approximately 154 × 10⁻³⁰ cm⁴ statvolt⁻¹—five times greater than XAG. This study highlights the potential of XAG derivatives as promising candidates for future organic photonic applications based on optical frequency conversion.