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

摘要

Photophysical properties of two novel guanidiniocarbonyl (I) and monocyclic guanidine (II)tetraphenylporphyrins and their interaction with DNA were investigated by steady-state and time-resolvedabsorption and emission spectroscopies.Istays predominantly monomeric in aqueous solutions. It producessinglet oxygen with high quantum yield(ΦΔ=0.67)that is typical for monomeric porphyrins. The electronicabsorption spectra ofIare not influenced by interaction with DNA. This is in contrast with monomeric tetratolylporphyrinsbearing phosphonium,ammonium and pyridinium groups where the formation of stablecomplexes with DNA is accompanied by a characteristic red shift of the Soret band.IIextensively forms HandJ-aggregates,which do not produce singlet oxygen(ΦΔ<0.01). In the presence of DNA only a smallfraction ofIIremains in monomeric form that is bound to DNA exterior.