title: Effect of intramolecular charge transfer on fluorescence and singlet oxygen production of phthalocyanine analogues.
abstract: Intramolecular charge transfer (ICT) was studied on a series of magnesium, metal-free and zinc complexes of unsymmetrical tetrapyrazinoporphyrazines and tribenzopyrazinoporphyrazines bearing two dialkylamino substituents (donors) and six alkylsulfanyl or aryloxy substituents (non-donors). The dialkylamino substituents were responsible for ICT that deactivated excited states and led to considerable decrease of fluorescence and singlet oxygen quantum yields. Photophysical and photochemical properties were compared to corresponding macrocycles that do not bear any donor centers. The data showed high feasibility of ICT in the tetrapyrazinoporphyrazine macrocycle and significantly lower efficiency of this deactivation process in the tribenzopyrazinoporphyrazine type molecules. Considerable effect of non-donor peripheral substituents on ICT was also described. The results imply that tetrapyrazinoporphyrazines may be more suitable for development of new molecules investigated in applications based on ICT.
authors: Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 50005, Hradec Kralove, Czech Republic.
authors: Lenka
authors: L
authors: Vachova
authors: Veronika
authors: V
authors: Novakova
authors: Kamil
authors: K
authors: Kopecky
authors: Miroslav
authors: M
authors: Miletin
authors: Petr
authors: P
authors: Zimcik
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D008274:Magnesium / Q000737:chemistry; D011789:Quantum Theory; D026082:Singlet Oxygen / Q000737:chemistry* / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: D056831:Coordination Complexes; D007211:Indoles; D054833:Isoindoles; D026082:Singlet Oxygen; D008274:Magnesium; C013647:phthalocyanine