Table 3.

Summary of Results Obtained from the TDFw⁵³ Fits of the Temperature Dependence of the three δ(pyrrole-H) and δ(pyrroline-H) of the [(TPC)Fe(L)₂]⁺ Complexes of this Study.

System	GSa	ESb	ΔE,c cm−1	MSDd	pyrroline-α and β-pyrrole carbon spin densities, ρC,e comments on quality or nature of fit
L = Im-d4	1/2	3/2	238	0.054	1: 0.0210, 0.0143 av (0.0064, 0.0308, 0.0057). OK for S = 1/2 dπ/dxy.
					2: 0.0117, 0.0127 av (0.0102, 0.0215, 0.0066). OK for S = 3/2.
L = 4-Me2NPy	1/2	3/2	132	0.050	1: 0.0152, 0.0121 av (0.0071, 0.0275, 0.0017). OK for S = 1/2 dπ/dxy.
					2: 0.0103, 0.0115 av (0.0083, 0.0206, 0.0057). Av. ρC too small for S = 3/2.
L = 2-MeHIm	1/2	3/2	639	0.083	1: 0.0091, 0.0098 av (0.0081, 0.0182, 0.0030). OK for S = 1/2 dπ/dxy.
					2: 0.0032, 0.0080 av (0.0061, 0.0130, 0.0049). Av. ρC too small for S = 3/2.
L = Py	1/2	3/2	700	0.149	1: 0.0032, 0.0042 av (0.0043, 0.0115, −0.0032). OK for S = 1/2 dxy/dπ.
					2: 0.0205, 0.0206 av (0.0048, 0.0402, 0.0169). OK for S = 3/2.
L = 4-CNPy	1/2	3/2	563	0.174	1: −0.0101, −0.0010 av (0.0011, 0.0011, −0.0050). OK for S = 1/2 dxy.
					2: 0.0335, 0.0133 av (0.0060, 0.0386, 0.0029). OK for S = 3/2.

^aGround state spin (S); electron configuration may be (d_xy)²(d_xz,d_yz)³ (abbreviated d_π), (d_xz,d_yz)⁴(d_xy)¹ (abbreviated d_xy), or a mixture of the two, as marked in the comments at the far right.

^bExcited state spin (S); all systems appear to have the electron configuration (d_xz,d_yz)³(d_xy)¹(d_z²)¹.

^cBest fit energy difference between ground and excited state (±30%).

^dMSD = mean-square deviation of the data points from the best fit.

^eSpin densities, ρ_C, obtained from fits, using the program TDFw, to Equation (1); 1 = ground state, 2 = excited state. Spin densities are given in the order pyrroline-H, average of three pyrrole-H, with individual pyrrole-H spin densities in parentheses in the order 7,18; 8,17; 12,13. Comments indicate how the spin density distribution is interpreted in terms of the sizes of the coefficients for each pyrrole position.