Table 1. Calculated (TDDFT/CAM-B3LYP/6-31G*)^a S₁ Energies and S₀ → S₁ Oscillator Strength.

	1a	1b	1c	1d	1e	2a	2b	2c	2d	2e	3a	3b	3c	3d	3e
ΔE S0 → S1(eV)	3.9	4.0	4.1	4.0	3.9	3.6	3.8	3.8	3.7	3.5	3.3	3.5	3.6	3.4	3.3
f	0.7	0.7	0.7	0.8	0.8	1.7	1.5	1.4	1.6	1.5	2.3	2.1	2.0	2.2	2.0

^aCHCl₃, SMD solvent model.¹⁶