International Journal of Photoenergy (Jan 2001)

Photophysical properties of two novel tetraphenylporphyrins substituted by guanidiniocarbonyl and monocyclic guanidine groups

  • Pavel Kubát,
  • Kamil Lang,
  • Vladimír Král,
  • Franz P. Schmidtchen

DOI
https://doi.org/10.1155/S1110662X01000186
Journal volume & issue
Vol. 3, no. 3
pp. 147 – 151

Abstract

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Photophysical properties of two novel guanidiniocarbonyl (I) and monocyclic guanidine (II) tetraphenylporphyrins and their interaction with DNA were investigated by steady-state and time-resolved absorption and emission spectroscopies. I stays predominantly monomeric in aqueous solutions. It produces singlet oxygen with high quantum yield (ΦΔ=0.67) that is typical for monomeric porphyrins. The electronic absorption spectra of I are not influenced by interaction with DNA. This is in contrast with monomeric tetratolylporphyrins bearing phosphonium,ammonium and pyridinium groups where the formation of stable complexes with DNA is accompanied by a characteristic red shift of the Soret band. II extensively forms Hand J-aggregates,which do not produce singlet oxygen (ΦΔ<0.01). In the presence of DNA only a small fraction of II remains in monomeric form that is bound to DNA exterior.