Table 2.

EPR Parameters for Low-spin (Cyano)iron(III)porphyrinates and Hemoproteins

complex	gxx	gyy	gzz	T(K)	phase	EPR type	ref.
[Fe(Porph)(CN)2]−
[K(18-C-6)][Fe(TMP)(CN)2]	1.20	1.68	3.47	4.2	microcrystalline	large gmax	tw
[K(18-C-6)][Fe(TMP)(CN)2]	2.54	2.54		4.2	CH2Cl2	axial	tw
[K((CH3)2CO)2][Fe(TPP)(CN)2]	0.52	1.05	3.70	6.0	single crystal	large gmax	16
[K((CH3)2CO)2][Fe(TPP)(CN)2]			3.67	4.2	microcrystalline	large gmax	tw
	2.57	2.57		4.2	microcrystalline	axial	tw
[K((CH3)2CO)2][Fe(TPP)(CN)2]			3.54	4.2	CH2Cl2-CH3OH	large gmax	tw
	1.76	2.21	2.74	4.2	CH2Cl2-CH3OH	rhombic	tw
[Fe(PPIX)(CN)2]−	1.03	2.42	3.75	–	–	large gmax	36
[Fe(THP)(CN)2]−			3.5	4.2	CH2Cl2-CH3OH	large gmax	20
[Fe(TPP)(CN)2]−			3.56	4.2	CH2Cl2-CH3OH	large gmax	21
[Fe(OMTPP)(CN)2]−			3.48	4.2	CH2Cl2	large gmax	37
[Fe(OETPP)(CN)2]−			3.31	4.2	CH2Cl2	large gmax	37
[Fe(OETPP)(CN)2]−			3.47	–	–	large gmax	38
[Fe(OEP)(CN)2]−			3.73	–	–	large gmax	38
[Fe(TTP)(CN)2]−a			3.6	4.2	CH2Cl2	large gmax	24
[Fe(TTP)(CN)2]−a	2.5	2.5		4.2	CH3OH	axial	24
[Fe(TMP)(CN)2]−	2.47	2.47	1.5	4.2	CH2Cl2-CH3OH	axial	21
[Fe(TEt3PP)(CN)2]−a,b	2.45	2.45	1.6	4.2	CD3OD	axial	23
[Fe(TEt3PP)(CN)2]−a,b	2.45	2.45	1.5	4.2	CH2Cl2-CH3OH	axial	21
[Fe(TiPr3PP)(CN)2]−a,b	2.45	2.45	1.5	4.2	CH2Cl2-CH3OH	axial	21
[Fe(TMeP)(CN)2]−	2.43	2.43	1.69	4.2	CH2Cl2-CH3OH	axial	20
[Fe(TEtP)(CN)2]−	2.47	2.47	1.61	4.2	CH2Cl2-CH3OH	axial	20
[Fe(TiPrP)(CN)2]−	2.35	2.35	1.82	4.2	CH2Cl2-CH3OH	axial	20
[Fe(TiPrP)(CN)2]−	2.42	2.42	1.74	4.2	CH2Cl2	axial	24
[Fe(TcPrP)(CN)2]−	2.47	2.47		4.2	CH2Cl2	axial	22
[Fe(TnPrP)(CN)2]−	2.49	2.49		4.2	CH2Cl2	axial	22
[Fe(TMP)(CN)2]−	2.56	2.56	1.70	–	–	axial	38
[Fe(QTPP)(CN)2]−	2.51	2.25	1.75	77	CH3OH	axial	39
[Fe(MQTPP)(CN)2]−	2.53	2.26	1.77	77	CH3OH	axial	39
[Fe(PTPP)(CN)2]−	2.46	2.29	1.7	77	CH3OH	axial	39
[Fe(Porph)(CN)(L)]
[Fe(TPP)(CN)(Py)]	0.34	1.76	3.31	6.0	single crystal	large gmax	16
[Fe(TPP)(CN)(Py)]			3.6	4.2	CH2Cl2	large gmax	tw
[Fe(TPP)(CN)(Py)]		1.8	3.3	4.2	microcrystalline	large gmax	tw
[Fe(TPP)(CN)(Py)]c		1.81	3.17	4.2	microcrystalline	large gmax	tw
[Fe(TPP)(CN)(1-MeIm)]		2.04	3.36	4.2	CH2Cl2	large gmax	tw
[Fe(TPP)(CN)(1-MeIm)]		1.92	3.51	4.2	microcrystalline	large gmax	tw
[Fe(TMP)(CN)(1-MeIm)]		2.04	3.28	4.2	CH2Cl2	large gmax	tw
[Fe(TMP)(CN)(1-MeIm)]		1.91	3.37	4.2	microcrystalline	large gmax	tw
[Fe(PPIX)(CN)(Im)]−	1.4	2.2	3.1	77	–	large gmax	40
[Fe(THP)(CN)(2-MeHIm)]			3.3	4.2	CH2Cl2-CH3OH	large gmax	41
[Fe(TMeP)(CN)(2-MeHIm)]	2.5	2.5	1.6	4.2	CH2Cl2-CH3OH	axial	41
[Fe(TEtP)(CN)(2-MeHIm)]	2.5	2.5	1.6	4.2	CH2Cl2-CH3OH	axial	41
[Fe(TiPrP)(CN)(2-MeHIm)]	2.45	2.45	1.67	4.2	CH2Cl2-CH3OH	axial	41
Cyano Hemoproteins
Mb, HIm, CN−	0.93	1.89	3.45	–	–	large gmax	42
Cytochrome c, CN−	0.73	1.85	3.47	–	–	large gmax	42
Sirohemin, 2CN−	2.37	2.37	1.78	15-20	–	axial	43

^aSimilar results were claimed for a number of meso-tetrakis(p-substituted-phenyl)porphyrin derivatives, p-X-TPP; X = OCH₃, H, F, Cl, COOCH₃, CF₃ and CN, but no data shown.

^bthe complex shows either an axial type signal or both axial and large g_max type signals in different solvents.[23]

^cCrystalline phase of Mössbauer sample.