TY - JOUR
T1 - In situ extended X-ray absorption fine structure of an iron porphyrin irreversibly adsorbed on an electrode surface
AU - Kim, S.
AU - Tryk, D. A.
AU - Bae, I. T.
AU - Sandifer, M.
AU - Carr, R.
AU - Antonio, M. R.
AU - Scherson, Daniel Alberto
PY - 1995/1/1
Y1 - 1995/1/1
N2 -
The analysis of iron K-edge XAFS for hemoproteins is a subject of maturity in bioinorganic chemistry. The analysis of the in situ iron K-edge EXAFS reported here for 40% [Fe(TMPP)]
2
O adsorbed on BP as a function of solution pH and applied potential has benefit from this precedence. The results that clearly emerge are that d(Fe-N
p
) is longer for the oxidized than for the reduced states. The range of d(Fe-N
p
) for the oxidized macrocycles (2.05-2.08 A) is typical of high-spin Fe
III
, whereas the corresponding range for the reduced macrocycle (2.01-2.04 A) is smaller and typical of either high- and/or intermediate-spin Fe
II
. The μ-oxo dimer structure, [Fe(TMPP)]
2
O, is maintained from pH 5-11 for the oxidized material. At lower solution pH values (1.2-3.1), the smaller value of d(Fe-N
p
) suggests the presence of a diaquo complex, [FeTMPP(OH
2
)
2
]
+
, whereas at higher pH values, i.e., 13, the dihydroxy species appears to predominate.
AB -
The analysis of iron K-edge XAFS for hemoproteins is a subject of maturity in bioinorganic chemistry. The analysis of the in situ iron K-edge EXAFS reported here for 40% [Fe(TMPP)]
2
O adsorbed on BP as a function of solution pH and applied potential has benefit from this precedence. The results that clearly emerge are that d(Fe-N
p
) is longer for the oxidized than for the reduced states. The range of d(Fe-N
p
) for the oxidized macrocycles (2.05-2.08 A) is typical of high-spin Fe
III
, whereas the corresponding range for the reduced macrocycle (2.01-2.04 A) is smaller and typical of either high- and/or intermediate-spin Fe
II
. The μ-oxo dimer structure, [Fe(TMPP)]
2
O, is maintained from pH 5-11 for the oxidized material. At lower solution pH values (1.2-3.1), the smaller value of d(Fe-N
p
) suggests the presence of a diaquo complex, [FeTMPP(OH
2
)
2
]
+
, whereas at higher pH values, i.e., 13, the dihydroxy species appears to predominate.
UR - http://www.scopus.com/inward/record.url?scp=0029326805&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029326805&partnerID=8YFLogxK
U2 - 10.1021/j100025a044
DO - 10.1021/j100025a044
M3 - Article
AN - SCOPUS:0029326805
SN - 0022-3654
VL - 99
SP - 10359
EP - 10364
JO - Journal of physical chemistry
JF - Journal of physical chemistry
IS - 25
ER -