A comprehensive discussion on photophysical properties of dihydropyridines: Experimental and theoretical studies

Abstract

In this article, the photophysical properties of DHPs, including 1,2-DHPs and 1,4-DHPs, were studied experimentally and theoretically. Their structural differences bring about different photophysical properties, and also lead to different photochemical properties. Specifically, a series of different substituted 1,2-DHPs and 1,4-DHPs were synthesized to measure their UV–Vis absorption and fluorescence emission spectra in diluted solutions and theoretical calculations were performed at the density functional theory (DFT) level. To describe the reactivities of the DHPs, time-dependent density functional theory (TDDFT) was used to optimize their ground- and excited-state structures, and their electronic excitation energies were calculated at the B3LYP-D3/def2-TZVP level. Frontier molecular orbitals and electron-hole distribution analyses were used to illustrate the electron transition types. The differences between the ground- and excited-state structures of the different DHPs were characterized by carrying out a root-mean-square-deviation (RMSD) analysis.