In situ extended X-ray absorption fine structure of an iron porphyrin irreversibly adsorbed on an electrode surface

S. Kim*, D. A. Tryk, I. T. Bae, M. Sandifer, R. Carr, M. R. Antonio, Daniel Alberto Scherson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)10359-10364
Number of pages6
JournalJournal of physical chemistry
Volume99
Issue number25
DOIs
Publication statusPublished - 1995 Jan 1
Externally publishedYes

ASJC Scopus subject areas

  • Engineering(all)
  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'In situ extended X-ray absorption fine structure of an iron porphyrin irreversibly adsorbed on an electrode surface'. Together they form a unique fingerprint.

Cite this