Fig. 2: Electronic properties of 2.

a Frontier orbitals and their energy levels of 2 calculated at the B3LYP/6-31G(d) level. b UV/Vis spectrum of 2 in benzene at room temperature with transitions calculated at the TD-DFT B3LYP/6-31G(d) level.

a Frontier orbitals and their energy levels of 2 calculated at the B3LYP/6-31G(d) level. b UV/Vis spectrum of 2 in benzene at room temperature with transitions calculated at the TD-DFT B3LYP/6-31G(d) level.