Solvent effects on the fac/mer-isomerization equilibrium of various complexes^a.

Complex	Difference from [2bFe](TFPB)2	fac/mer in CD3CN	fac/mer in CD3CN/CDCl3 = 1/4	fac/mer in CDCl3
[2bFe](TFPB)2	—	71 : 29	39 : 61	10 : 90
[1aFe](TFPB)2	No group A, B	83 : 17	—	64 : 36
[1bFe](TFPB)2	No group A	76 : 24	—	22 : 78
[2aFe](TFPB)2	No group B	75 : 25	—	13 : 87
[2bFe](PF6)2	PF6−	71 : 29	—	4 : 96
[2bZn](TFPB)2	ZnII	90 : 10	67 : 33	—
[(3b)3Fe](TFPB)2	Without pivot	22 : 78b	—	21 : 79b

^aThe fac/mer ratios were calculated from the signals of the proton f (2 position of the benzene ring of the pivot) (see Fig. 2).

^bCalculated from the signals of the formyl proton q (see Fig. S61).