Table 2. ZFS Parameters and Relative Sublevel Populations of the Zinc and Free-Base Porphyrins Determined through Simulation of the Transient EPR Spectra Recorded at Wavelengths Corresponding to the Planar Conformations.

	Zinc Porphyrins			Free-Base Porphyrins
	|D| [MHz]	|E| [MHz]	pX:pY:pZ	|D| [MHz]	|E| [MHz]	pX:pY:pZ
P1	898 ± 5	161 ± 2	0.05:0.00:0.95	1024 ± 3	144 ± 2	0.47:0.53:0.00
P2	1117 ± 9	284 ± 2	0.88:0.00:0.12	1053 ± 3	311 ± 4	0.00:0.29:0.71
P3	1169 ± 7	269 ± 2	0.46:0.00:0.54	1087 ± 3	321 ± 2	0.00:0.08:0.92
P4	1195 ± 8	273 ± 2	0.28:0.00:0.72	1116 ± 6	308 ± 5	0.00:0.04:0.96