Structure–Property Relationship and Systematic Study of a Series of Terpyridine Based Nonlinear Optical Compounds: DFT Computation of Interactive Design

Abstract: The objective of this research work is to study the nonlinear optical (NLO) response of terpyridine ligand complexes. Terpyridine ligand based compounds were studied through quantum chemical calculations by using B3LYP/6-31 g (d,p) basis sets. Density functional theory (DFT) calculations were performed to examine nonlinear optical properties of these newly designed compounds. Triphenylamine as electron donor and terpyridine ligand as an electron acceptor were connected directly. The π-spacers were also used to connect the donor and acceptor to increase conjugation. Preparation and characterization of novel compounds or materials for NLO, especially for second harmonic generation (SHG), based on hydrogen-bonded compounds of organic nitrogen containing bases such as terpyridine is used in this research work. Terpyridine ligand has ability to stabilize the complexes. Chelation and supramolecular organization play key role in designing new second-order NLO materials/compounds. NLO compounds have emerged as one of the most attractive fields of current research in view of their vital applications in areas like optical modulation, optical switching, optical logic, frequency shifting and optical data storage for the developing technologies in telecommunications and in efficient signal processing. These newly designed chromophore/compounds show high thermal stability and large optical nonlinearity. In studied compounds dye-5 has its maximum NLO response calculated to be 1967.23 a.u. Graphical Abstract: The computed β_tot values increase by increasing conjugation bridge along with the incorporation of an electron acceptor (F) at the end of terpyridine ring. [Figure not available: see fulltext.].