Boosting the singlet oxygen photosensitization abilities of Zn(ii) phthalocyanines through functionalization with bulky fluorinated substituents

Abstract

Non-aggregated, crosswise ZnPcs functionalized with bis(trifluoromethyl)phenyl groups in facing isoindoles have proved efficient photosensitizers for singlet oxygen generation.

Assessing Amphiphilic ABAB Zn(II) Phthalocyanines with Enhanced Photosensitization Abilities in In Vitro Photodynamic Therapy Studies Against Cancer

“…These values should be considered with caution since indirect methods could be subjected to different variables, but are useful for comparative purposes. From those results we can infer that the larger the number of bulky fluorinated groups at α-positions, the better the 1 O 2 generation efficiency, as otherwise expected considering previous studies with related compounds [22], which show the important role of the bulky, electron-withdrawing bis(trifluoromethyl) groups in the 1 O 2 production . It is important to mention that aggregation is not considered to evaluate these results since the three compounds are non-aggregated in DMSO (see below).…”

“…The target Pcs have been synthesized following two different synthetic pathways: (i) a divergent route that allows to obtain generic ABAB and A3B Zn(II)Pcs functionalized with phenolic groups (ABAB-2 and A3B-2 Zn(II)Pcs in Scheme 1), which represent synthons, over which it is possible to add hydrophilic groups such as PEG chains; and (ii) the straightforward preparation of ABAB-1 and A3B-1 (and also A4-1) starting from adequately functionalized phthalonitriles. We have performed aggregation and photophysical studies in solution over this family of compounds in order to ratify our previous results regarding the enhanced 1 O2 generation abilities of the nonaggregated ABAB-type Zn(II)Pc compounds with regard to their A3B and A4 counterparts [22]. Going one step further, we have performed in vitro assays to examine the toxicity of ABAB-1, A3B-1 and A4-1 in different tumor cells, i.e., SCC-13 and HeLa, as well as their cell localization.…”

“…The samples were excited at: ABAB-1 667 (THF) and 702 nm (toluene); A 3 B-1 665 (THF) and 670 nm (toluene); A 4 -1 693 (THF) and 672 nm (toluene). Fluorescent quantum yields (Φ F ) were determined by comparing the integrated fluorescent intensity of optically matched solutions between samples (S) and reference (R) ZnPc in 1-propanol (Φ F = 0.20) [22]. The samples were excited at: ABAB-1 609 (THF) and 603 nm (toluene); A 3 B-1 610 (THF) and 605 nm (toluene); A 4 -1 610.5 (THF) and 610 nm (toluene).…”

Distorted Phthalocyanines by Click Chemistry: Photoacoustic, Photothermal, and Surface‐Enhanced Resonance Raman Studies

“…Compared to the planar derivatives, distorted Pc have unique photophysical attributes such as near IR (NIR) absorption, low fluorescence and 1 O 2 quantum yields, solvent dependency, different redox potentials, distinct catalytic cycles, and diverse materials properties . Most Pc distortion is achieved by steric crowding of the peripheral substituents, especially at neighboring α,α‐positions . To develop a lipophilic or amphipathic Pc derivative, we substituted a commercial surfactant, isodecyloxypropyl‐1,3‐diamino‐propane (tomamine®), onto ZnF 16 Pc via a simple one‐step annulation to yield a seven‐membered ring on adjacent β‐positions of an isoindole (Scheme ).…”

Effect of Position and Connected Atom on Photophysical and Photochemical Properties of Some Fluorinated Metallophthalocyanines

“…Among the diverse MPc substituted Pcs, alkoxy‐ and especially alkylthio‐substituted MPcs show excellent photosensitizing properties (24,25). Fluorinated phthalocyanines have been also reported to show improved photosensitizer activity for PDT compared to nonfluorinated derivatives (25–28).…”