Table 1.

Selected geometrical parameters for the hemichromes in the β subunits of the Hb[α-Fe^III(H₂O)][β-Fe^III(His)₂] derivatives from the reactions of ferric Hb with t-BuNHOH and PhNHOH

	from t-BuNHOHa		from PhNHOHb
	β1	β2	β1	β2
θp (°)	79	87	90	90
θd (°)	84	80	80	79
Nε2im-Fe-Nε2im (°)	174	178	177	176
ω (°)	78	70	72	67
Fe-Nε2im (Å)
Prox.	2.4	2.6	2.2	2.2
Dist.	2.4	2.4	2.1	2.1
Cαprox- Cαdist (Å)	13.0	12.9	12.7	12.7
βcys93 oxidized	no	no	no	yes

^aHemichrome β-subunit from the reaction with t-BuNHOH.

^bHemichrome β-subunit from the reaction with PhNHOH.