Relaxation times for [Fe(bpy)₃]²⁺ in acetonitrile for various counterions at different concentrations following ¹A₁ → ¹MLCT excitation at 550 nm.

	Ground state recovery (ps)
	Abs = 0.1	Abs = 0.4	Abs = 0.7	Abs = 1.0
[Fe(bpy)3]Cl2	1015 ± 40	1020 ± 15	1005 ± 45	1010 ± 115
[Fe(bpy)3]Br2	1020 ± 30	1015 ± 15	1015 ± 25	970 ± 90
[Fe(bpy)3]I2	1040 ± 30	1015 ± 15	1010 ± 30	1045 ± 110
[Fe(bpy)3](PF6)2	1025 ± 25	1020 ± 20	1005 ± 40	1020 ± 105
[Fe(bpy)3](BPh4)2	1030 ± 40	1025 ± 15	1005 ± 30	1025 ± 110
[Fe(bpy)3](BArF4)2	1045 ± 45	1020 ± 20	1030 ± 30	1035 ± 120