Comparative photophysical investigation of oxygen and sulfur as covalent linkers on octaalkylamino substituted zinc(ii) phthalocyanines

Abstract

This work describes a systematic comparison of oxygen and sulfur as covalent linkers on octasubstituted zinc(II) phthalocyaninates. Most photophysical parameters that make phthalocyanines technologically relevant, e.g. molar absorption coefficients, fluorescence, triplet and singlet oxygen quantum yields, are essentially unaffected by the substitution. The energy content of the first triplet state was observed to be close to the first singlet state of molecular oxygen for both spacers, as follows from photoacoustic determinations. Nonetheless, a bathochromic shift of 30 nm in the absorption and emission maxima, and of 60 nm in the triplet-triplet absorption spectra were observed when alkyloxyl and alkylsulfanyl moieties were alternatively present. Fluorescence quantum yields proved to be much more sensitive towards aggregation than the absorption spectra. Therefore, a novel fluorescence data analysis provided aggregation parameters and photophysical properties of the monomeric species. It was observed that the tendency towards dimerization is slightly higher with sulfur linkers. These results set a foundation for the rational design of conveniently substituted phthalocyaninates with different connectors between the macrocycle and the side chains.

A comparative study of a novel lipophilic phthalocyanine incorporated into nanoemulsion formulations: Photophysics, size, solubility and thermodynamic stability

“…5 shows the incorporation of ZnPc in homogeneous media (THF) and into nanoemulsions. The absorption spectra of ZnPc incorporated into NE1 and NE2 in the range of 500e800 nm range were similar to those previously reported for other zinc(II) phthalocyanines in homogeneous media [2,13,30]. The spectra in THF and into nanoemulsions recorded at [ZnPc] ¼ 0.6 mMe4 mM showed a linear behavior (inset Fig.…”

Photodynamic effects of isosteric water-soluble phthalocyanines on human nasopharynx KB carcinoma cells

“…This effect was observed for phthalocyanines 7e10 and cationic derivatives 11e14 respectively [31,32]. Such bathochromic shift into the therapeutic window is highly promising for a second-generation photosensitizer for biomedical purposes in photodynamic therapy.…”

“…Diphenylisobenzofuran (DPBF), N,N-diethyl-4-nitrosoaniline, imidazol and Methylene blue (MB) as well as all reagents were provided by SigmaeAldrich. Tetra-t-butylphthalocyaninatozinc(II) [26], 2,3,9,10,16,17,23,24-octakis(decyloxi)phthalocyaninatozinc(II) (ZnPc) [33] and 2,3,9,10,16,17,23,24-octakis[(N,N-dimethylaminoethylsulfanyl)]phthalocyaninatozinc(II) [31] were synthesized in our laboratory. …”

Photoaktive hybride Nanomaterialien für gezieltes Anbinden, Markieren und Töten von Antibiotika‐resistenten Bakterien

“…Phthalocyanine eignen sich ausgezeichnet für die Entwicklung von Phototherapeutika, da sie wenig giftig und sehr stabil sind, eine hohe 1 O 2 -Produktion gewährleisten und Licht im "therapeutischen Fenster" absorbieren. [1][2][3]17] Insbesondere wurden Zn II -und Si IV -Phthalocyanine als vielversprechende Photosensibilisatoren untersucht. [1][2][3] Auch hier sind Aminogruppen wichtig, um die biologische Aktivität der Farbstoffe zu modulieren, [18,19] die mit einer Vielzahl an Strukturen mit interessanten photophysikalischen und photobiologischen Eigenschaften verknüpft werden können.…”

“…[20][21][22][23][24] Das Aggregieren dieser Verbindungen ist jedoch ein Nachteil, den es zu vermeiden gilt, um die photosensibilisierenden Eigenschaften der Makrocyclen zu nutzen. [17] Wir haben eine Nanoarchitektur konzipiert, die Fluoreszenzbildgebung, photosensibilisierende Eigenschaften und Anhaftung an Zellen vereint (Abbildung 1). Hierzu wurden Zeolith L-Nanokristalle mit 50 nm in Länge und Durchmesser mit grün emittierendem DXP (N,N'-Bis(2,6-dimethylphenyl)perylen-3,4,9,10-tetracarbodiimid) durch Gasphasenaustausch beladen.…”