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An improved model for malaria pigment and β ‐hematin: Fe(OEP)picrate
Author(s) -
Puntharod Ratchadaporn,
Haller Kenneth J.,
Robertson Evan G.,
Gwee Eunice S. H.,
Izgorodina Ekaterina I.,
Wood Bayden R.
Publication year - 2017
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5176
Subject(s) - picrate , chemistry , raman spectroscopy , pigment , hemozoin , intermolecular force , resonance raman spectroscopy , crystallography , photochemistry , resonance (particle physics) , density functional theory , molecule , heme , stereochemistry , computational chemistry , organic chemistry , optics , ion , physics , particle physics , enzyme
Synthesis and crystallographic and spectroscopic structural characterization, along with spectral band assignments calculated by using density functional theory (M06L/cc‐pVDZ and B3LYP/6‐31G(d)), are reported for Fe(OEP)picrate as a model for hemozoin (malaria pigment) and its synthetic analog β ‐hematin, which are spectroscopically identical. The average Fe–N distance, 2.044(12) Å, and the Raman modes indicate a high‐spin five‐coordinate iron(III) complex. Resonance enhancement is observed for the totally symmetric oxidation state marker band ν 4 along with the characteristic bands of C β ‐substituted hemes in the ranges of 1621–1639 cm −1 for ν as (C α C m ) and 750–756 cm −1 for ν (pyr breathing) similar to β ‐hematin and hemozoin when using near‐IR excitation wavelengths. The similarity of the resonance Raman spectral profiles for Fe(OEP)picrate and β ‐hematin, along with the structural results, indicates that Fe(OEP)picrate is an excellent model for understanding the stereochemistry and intermolecular interaction of β ‐hematin. Copyright © 2017 John Wiley & Sons, Ltd.