Interpretation of the UV-vis spectra of the meso(ferrocenyl)-containing porphyrins using a TDDFT approach: is Gouterman's classic four-orbital model still in play?

Victor N Nemykin; Ryan G Hadt

doi:10.1021/jp1083828

Interpretation of the UV-vis spectra of the meso(ferrocenyl)-containing porphyrins using a TDDFT approach: is Gouterman's classic four-orbital model still in play?

J Phys Chem A. 2010 Nov 18;114(45):12062-6. doi: 10.1021/jp1083828. Epub 2010 Oct 27.

Authors

Victor N Nemykin¹, Ryan G Hadt

Affiliation

¹ Department of Chemistry and Biochemistry, University of Minnesota-Duluth, Duluth, Minnesota 55812, USA. vnemykin@d.umn.edu

PMID: 20979401
DOI: 10.1021/jp1083828

Abstract

The vertical excitation energies of H(2)TPP [TPP = 5,10,15,20-tetraphenylporphyrin(2-)], H(2)FcPh(3)P [FcPh(3)P = 5-ferrocenyl-10,15,20-triphenylporphyrin(2-)], cis-H(2)Fc(2)Ph(2)P [cis-Fc(2)Ph(2)P = 5,10-bisferrocenyl-15,20-diphenylporphyrin (2-)], trans-H(2)Fc(2)Ph(2)P [trans-Fc(2)Ph(2)P = 5,15-bisferrocenyl-10,20-diphenylporphyrin(2-)], H(2)Fc(3)PhP [H(2)Fc(3)PhP = 5,10,15-trisferrocenyl-20-phenylporphyrin(2-)], and H(2)TFcP [TFcP = 5,10,15,20-tetraferrocenylporphyrin(2-)] were investigated using a time-dependent density functional theory (DFT) approach and compared to their experimental UV-vis spectra in the 10,000-30,000 cm(-1) region. It was shown that the lowest energy transitions in meso(ferrocenyl)-containing porphyrins have predominantly ferrocene-to-porphyrin charge transfer character, while the porphyrin-centered π-π* transitions predicted by the Gouterman's classic four-orbital model still have the largest intensities in the UV-vis region. The number of predominantly ferrocene-to-porphyrin charge transfer transitions increases with the number of ferrocene substituents and becomes dominant in H(2)TFcP.