Fig. 2. Top and side views of the X-ray crystal structures of (a) 8 and (b) 9. Thermal ellipsoids are drawn at 50% probability. Pictorial Frontier molecular orbitals and energy levels of (c) 8 and (d) 9 calculated using the B3LYP/6-31G(d) level of theory. (e) Normalized UV-vis absorption and fluorescence spectra of 8 and 9 in CH₂Cl₂ at rt.