Unknown

Dataset Information

0

3D Motions of Iron in Six-Coordinate {FeNO}(7) Hemes by Nuclear Resonance Vibration Spectroscopy.


ABSTRACT: The vibrational spectrum of a six-coordinate nitrosyl iron porphyrinate, monoclinic [Fe(TpFPP)(1-MeIm)(NO)] (TpFPP=tetra-para-fluorophenylporphyrin; 1-MeIm=1-methylimidazole), has been studied by oriented single-crystal nuclear resonance vibrational spectroscopy (NRVS). The crystal was oriented to give spectra perpendicular to the porphyrin plane and two in-plane spectra perpendicular or parallel to the projection of the FeNO plane. These enable assignment of the FeNO bending and stretching modes. The measurements reveal that the two in-plane spectra have substantial differences that result from the strongly bonded axial NO ligand. The direction of the in-plane iron motion is found to be largely parallel and perpendicular to the projection of the bent FeNO on the porphyrin plane. The out-of-plane Fe-N-O stretching and bending modes are strongly mixed with each other, as well as with porphyrin ligand modes. The stretch is mixed with v50 as was also observed for dioxygen complexes. The frequency of the assigned stretching mode of eight Fe-X-O (X=N, C, and O) complexes is correlated with the Fe-XO bond lengths. The nature of highest frequency band at ?560?cm(-1) has also been examined in two additional new derivatives. Previously assigned as the Fe-NO stretch (by resonance Raman), it is better described as the bend, as the motion of the central nitrogen atom of the FeNO group is very large. There is significant mixing of this mode. The results emphasize the importance of mode mixing; the extent of mixing must be related to the peripheral phenyl substituents.

SUBMITTER: Peng Q 

PROVIDER: S-EPMC4999340 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature

altmetric image

Publications

3D Motions of Iron in Six-Coordinate {FeNO}(7) Hemes by Nuclear Resonance Vibration Spectroscopy.

Peng Qian Q   Pavlik Jeffrey W JW   Silvernail Nathan J NJ   Alp E Ercan EE   Hu Michael Y MY   Zhao Jiyong J   Sage J Timothy JT   Scheidt W Robert WR  

Chemistry (Weinheim an der Bergstrasse, Germany) 20160321 18


The vibrational spectrum of a six-coordinate nitrosyl iron porphyrinate, monoclinic [Fe(TpFPP)(1-MeIm)(NO)] (TpFPP=tetra-para-fluorophenylporphyrin; 1-MeIm=1-methylimidazole), has been studied by oriented single-crystal nuclear resonance vibrational spectroscopy (NRVS). The crystal was oriented to give spectra perpendicular to the porphyrin plane and two in-plane spectra perpendicular or parallel to the projection of the FeNO plane. These enable assignment of the FeNO bending and stretching mode  ...[more]

Similar Datasets

| S-EPMC4295236 | biostudies-literature
| S-EPMC5555598 | biostudies-literature
| S-EPMC4167049 | biostudies-literature
| S-EPMC1502394 | biostudies-literature
| S-EPMC5117133 | biostudies-literature
| S-EPMC3993889 | biostudies-literature
| S-EPMC3273671 | biostudies-literature
| S-EPMC4251817 | biostudies-literature
| S-EPMC7735705 | biostudies-literature
| S-EPMC6002827 | biostudies-literature