Modelling of UV-molecular spectra of several bis-pyrazolopyridines derivatives

Quantum chemical simulations of UV-absorption spectra in substituted bis-pyrazolopyridines were done. As a theoretical tool time dependent density functional theory (TDDFT) method with Vosko-Wilk-Nusair parameterisation was applied. Comparison of the theoretically simulated UV-absorption spectra with experimental data was performed. Crucial role of π-conjugated bonds within the backside phenyl rings is demonstrated. Physical insight of the several observed discrepancies between the calculations and experimental data is discussed. A comparison of the TDDFT and several semi-empirical approaches is given.