Calculated wavelengths (nm), oscillator strengths (f) and corresponding transition and assignment for selected R1 to R4 complexes^a.

Complex	λ (nm)	f	Transition	Assignment*
R1	394	0.4434	H → L+1 (96%)	LLCT/MLCT(π → π*/d → π*)
	312	0.4878	H−6 → L (51%)	LbpyLbpyCT(π → π*)
	270	0.3378	H−1 → L+4 (36%)	LLCT/MLCT(π → π*/d → π*)
			H−2 → L+5 (13%)	MLCT(d → π*)
R2	393	0.4774	H → L+1 (97%)	LLCT/MLCT(π → π*/d → π*)
	311	0.3654	H−6 → L (65%)	LbpyLbpyCT(π → π*)
	280	0.4279	H−5 → L+1 (77%)	LLCT/MLCT(π → π*/d → π*)
R3	396	0.4003	H → L+1 (95%)	LLCT/MLCT(π → π*/d → π*)
	279	0.2794	H−7 → L+1 (52%)	LLCT(π → π*)
	278	0.5497	H−5 → L+1 (40%)	LLCT/MLCT(π → π*/d → π*)
R4	398	0.3026	H → L+1 (72%)	LLCT/MLCT(π → π*/d → π*)
	310	0.3191	H → L+3 (41%)	LLbpyCT/MLbpyCT(π → π*/d → π*)
			H−6 → L (41%)	LbpyLbpyCT(π → π*)
	280	0.4969	H−5 → L+1 (58%)	LLCT/MLCT(π → π*/d → π*)

^abpy: 2,2′-bpy.