Resonance Raman enhancement of FeIV=O stretch in high-valent iron porphyrins: an insight from TD-DFT calculations.
Density functional theory (DFT) has been applied to explain the origin of resonance Raman enhancement associated with the Fe(IV)=O stretch observed in iron(IV)oxo porphyrins. To accomplish this electronic excitations of the Im-(Por)Fe(IV)=O model were computed in the 1.5-4.0 eV spectral range using time-dependent DFT (TD-DFT). All electronic transitions having dominant pi-->pi* character were analyzed and assigned in terms of one-electron excitations. It was found that the most intense Soret band has a multi-component character, but the pi (a(2u))-->pi*(d(xz),d(yz)) and pi (a(1u))-->pi*(d(xz),d(yz)) electronic excitations are primarily responsible for observed resonance enhancement of the Fe(IV)=O stretch.
Kozlowski
Pawel M
PM
Department of Chemistry, University of Louisville, 2330 South Brook Street, Louisville, KY 40292, USA. pawel@louisville.edu
Kuta
Jadwiga
J
Ohta
Takehiro
T
Kitagawa
Teizo
T
D007501:Iron / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
D008665:Metalloporphyrins; C066317:ferryl iron; D007501:Iron; D010100:Oxygen