Synthesis, Supramolecular Behavior, and In Vitro Photodynamic Activities of Novel Zinc(II) Phthalocyanines “Side‐strapped” with Crown Ether Bridges

Abstract

Two new tetra- or di-α-substituted zinc(II) phthalocyanines 5 and 6 have been prepared through a "side-strapped" method. In the molecules, the adjacent benzene rings of the phthalocyanine core are linked at α-position through a triethylene glycol bridge to form a hybrid aza-/oxa-crown ether. The tetra-α-substituted phthalocyanine 5 shows an eclipsed self-assembly property in CH2Cl2 and the effect on the di-α-substituted analogue 6 is significantly weakened. Furthermore, the crown ethers of these compounds can selectively complex with Fe(3+) or Cu(2+) ion in DMF, leading to formation of J-aggregated nano-assemblies, which can be disaggregated in the presence of some organic or inorganic ligands, such as triethylamine, tetramethylethylenediamine, CH3COO(-), or OH(-). In addition, both compounds are efficient singlet oxygen generators with the singlet oxygen quantum yields (Φ(Δ)) of 0.54-0.74 in DMF relative to unsubstituted zinc(II) phthalocyanine (Φ(Δ)=0.56). They exhibit photodynamic activities toward HepG2 human hepatocarcinoma cells, but the compound 6, which has more than 40-fold lower IC50 value (0.08 μM) compared to the analogue 5 (IC50=3.31 μM), shows remarkablely higher in vitro photocytotoxicity due to its significantly higher cellular uptake and singlet oxygen generation efficiency. The results suggest that these compounds can serve as promising multifunctional materials both in (opto)electronic field and photodynamic therapy.

Superior Sensor for Be2+ Ion Recognition via the Unprecedented Octahedral Crystal Structure of a One-Dimensional Coordination Polymer of Crown Fused Zinc Phthalocyanine

“…In fact, the alkali- or alkaline-earth-metal-induced H aggregate is known to be the predominant form of aggregation of especially crown-substituted Pc due to the strong π–π interaction between Pc molecules, while metal- or solvent-induced J aggregation of Pc has been reported in only a few cases so far. The changes observed in the UV–vis and fluorescence spectra of P-CfZnPc originating from Be 2+ -induced J aggregation is quite similar to the metal- or solvent-induced J aggregation observed in previous studies. , The polymeric structure and Be 2+ -induced J-aggregated form of P-CfZnPc were also confirmed by MALDI-TOF mass spectra (Figure ), scanning electron microscopy (SEM) images of the spin-coated films of P-CfZnPc and its Be complex on glass (Figure ), and electrochemistry (discussed below).…”

“…The changes observed in the UV−vis and fluorescence spectra of P-CfZnPc originating from Be 2+ -induced J aggregation is quite similar to the metal-or solvent-induced J aggregation observed in previous studies. 73,75 The polymeric structure and Be 2+ -induced J-aggregated form of P-CfZnPc were also confirmed by MALDI-TOF mass spectra (Figure 9), scanning electron microscopy (SEM) images of the spin-coated films of P-CfZnPc and its Be complex on glass (Figure 10), and electrochemistry (discussed below).…”

Molecular Interactions in Organic Nanoparticles for Phototheranostic Applications

“…Polypyrrole (PPy) nanoparticles are another class of conjugated polymers that exhibit high molar extinctions in the NIR and excellent photothermal conversion efficiencies. [175][176][177]180 Chen et al reported the synthesis of a strongly absorbing PPy nanoparticle with an extinction coefficient of 2.38 × 10 10 M −1 cm −1 at 808 nm, while conversion efficiency was 44.7%. 177 Using these nanoparticles, they were able to induce tumor cell kill by injecting PPy at a dose of 10 mg kg −1 and irradiating the area with 808 nm light (1 W cm −2 ; 5 min).…”

Applications of Photoinduced Phenomena in Supramolecularly Arranged Phthalocyanine Derivatives: A Perspective

“…Another reported approach to overcome Pc drawbacks as PS agent envisaged the chemical modification of Pc derivatives by developing novel synthetic routes and in order to tune Pc molecules aggregation and supramolecular organization [180,181]. Huang and collaborators [180] synthetized two ZnPc derivatives, a tetra-and a di-α-substituted ZnPc. A triethylene glycol (TEG) chain was used to form a hybrid aza-/oxa-crown-substituted phthalocyanine.…”