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Two series of unsymetrically functionalized, carboxyethynylphenyl-containing porphyrins, bearing either 2,4,6-triisopropylphenyl or triphenylamino substituents at three of the four meso positions, have been prepared by Sonogashira coupling from the corresponding ethynyl- or iodo-functionalized porphyrin precursors. UV/Vis and electrochemical measurements have been performed to determine the electronic features of these new compounds and, hence, their potential as dyes for dye-sensitized solar cells. [ABSTRACT FROM AUTHOR]

A series of homoleptic ([TbIII(Pc)2]) and heteroleptic ([TbIII(Pc)(Pc′)]) TbIII bis(phthalocyaninate) complexes that contain different peripheral substitution patterns (i.e., tert-butyl or tert-butylphenoxy groups) have been synthesized in their neutral radical forms and then reduced into their corresponding anionic forms as stable tetramethylammonium/tetrabutylammonium salts. All of these compounds were spectroscopically characterized and their magnetic susceptibility properties were investigated. As a general trend, the radical forms exhibited larger energy barriers for spin reversal than their corresponding reduced compounds. Remarkably, heteroleptic complexes that contain electron-donor moieties on one of the two Pc ligands show higher effective barriers and blocking temperatures than their homoleptic derivatives. This result is assigned to the elongation of the NTb distances in the substituted macrocycle, which brings the terbium(III) ion closer to the unsubstituted Pc, thus enhancing the ligand-field effect. In particular, heteroleptic [TbIII(Pc)(Pc′)] complex 4, which contains one octa( tert-butylphenoxy)-substituted Pc ring and one bare Pc ring, exhibits the highest effective barrier and blocking temperature for a single-molecule magnet reported to date. [ABSTRACT FROM AUTHOR]

Nanostructuring of phthalocyanine-based materials is a powerful tool towards the preparation of new materials with outstanding properties. It has been previously shown that porphyrin-functionalized and phthalocyanine-functionalized polymers give rise to nanosized aggregates. With the goal in mind of searching new phthalocyanine-containing polymeric materials that are able to self-organize into stable supramolecular nanostructures, we have prepared unsymmetrically functionalized Zn(II) phthalocyanines that are able to behave as initiators in the atom transfer radical polymerization of styrene. Hybrid phthalocyanine-polystyrene materials of different tail lengths have been prepared, and their self-organization behavior was studied by means of UV-Vis spectroscopy and transmission electron microscopy. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

HiPco single-walled carbon nanotubes (SWNTs) have been sidewall-functionalized with phtha- locyanine addends following two different approaches: a straightforward Prato reaction with N-octylglycine and a formyl-containing phthalocyanine, and a stepwise approach that involves a former Prato cycloaddition to the double bonds of SWNTs using p-formyl benzoic acid followed by esterification of the derivatized nanotubes with an appropriate phthalocyanine molecule. The two materials obtained by these routes comprise different carbon/Pc-addenda ratios, as evidenced by Raman, TGA, and photophysical studies. The occurrence of electron transfer from photoexcited phthalocyanines to the nanotube framework in these ZnPc-SWNT ensembles is observed in transient absorption experiments, which confirm the absorption of the one-electron oxidized ZnPc cation and the concomitant bleaching of the van Hove singularities typical from SWNTs. Charge-separation (i.e., 2.0 × 1010 -1) and charge-recombination (i.e., 1.5 × 106 s-1) dynamics reveal a notable stabilization of the radical ion pair product in dimethylformamide. [ABSTRACT FROM AUTHOR]

• Porphyrinoid-based photo- and electro-active systems within the Torres-Guldi collaboration are reviewed. • Covalent and non-covalent electron donor–acceptor systems based on phthalocyanines/subphthalocyanines and fullerenes. • Covalent and non-covalent electron donor–acceptor systems based on porphyrinoids and non-fullerenic electroactive moieties. • Phthalocyanines for solar cell applications. • Porphyrinoids for sensing, biochemical, and biomedical applications. This review highlights the combined effort of the Torres and Guldi groups in the preparation and study of porphyrinoid-based photo- and electro-active systems. The perfect synergy between the deep knowledge on the chemistry of porphyrinoids and advanced carbon allotropes possessed by the Spanish team, and the profound expertise in the advanced photophysical characterization and photon- and charge-management held by the German group represents the real asset of this transnational collaboration. Along the last twenty years, the two groups have developed a plethora of electron donor–acceptor architectures based mainly on phthalocyanines and subphthalocyanines, but also porphyrins and other porphyrinoids, connected, either covalently or through supramolecular interactions, to several electroactive units such as advanced carbon allotropes, that is, fullerenes, carbon nanotubes, and graphene, among others. Important guidelines relating the structural and electronic features of such photo- and electro-active species with physical aspects such as the dynamics of charge separation, charge transport, charge shift, and charge recombination processes have been obtained. This knowledge has resulted crucial for the implementation of many of these systems into applied research fields such as optoelectronics, solar energy conversion, and biomedicine. [ABSTRACT FROM AUTHOR]

We have previously demonstrated that singlet oxygen photosensitization abilities of Zn(II) phthalocyanines (Zn(II)Pcs) are enhanced through α-functionalization with bulky fluorinated substituents (i.e., bis(trifluoromethyl)phenyl units) at facing positions of ABAB Zn(II)Pcs, where A and B refer to differently functionalized isoindoles. In this work, we have prepared the Zn(II)Pc ABAB 1 endowed with hydrophilic triethylene glycol monomethyl ether (i.e., at the A isoindoles) to provide solubility in aqueous media, together with its A3B and A4 counterparts, and compared their ability to behave as photosensitizers for photodynamic therapy. All photophysical data, aggregation studies and preliminary in vitro biological assays in cell cultures of SCC-13 (squamous cell carcinoma) and HeLa (cervical cancer cells), have proved ABAB 1 as the best photosensitizer of the series. [ABSTRACT FROM AUTHOR]

Herein we report on the acceleration of the Diels‐Alder reaction between a series of 9‐functionalized anthracenes and C60/C70 encapsulated in a water‐soluble metallo‐organic Pd(II)‐subphthalocyanine cage (SubPc‐cage), which performs as a catalytic molecular reactor that provides a beneficial hydrophobic environment. Negatively and positively charged anthracenes do not react either with C60 or C70, due to a favored solvation in water medium and/or to detrimental interactions with positively‐charged Pd(II) corners of SubPc‐cage. Experiments with C60 and C70 rendered parallel results, although C70 proved more reactive, leading to anthracene cycloadducts by reaction in the α bonds. All the results have been rationalized by theoretical calculations at the GFN2‐xTB level. [ABSTRACT FROM AUTHOR]

Herein we report the first example of a supramolecular cage that works as a catalytic molecular reactor to perform transformations over fullerenes in aqueous medium. Taking advantage of the ability of metallo–organic Pd(II)‐subphthalocyanine (SubPc) capsules to form stable host:guest complexes with C60, we have prepared a water‐soluble cage that provides a hydrophobic environment for conducting cycloadditions over encapsulated C60, namely, Diels–Alder reactions with anthracene. Indeed, the presence of catalytic amounts of SubPc cage dissolved in water promotes co‐encapsulation of insoluble C60 and anthracene substrates, allowing the reaction to occur inside the cavity under mild conditions. The lower stability of the host:guest complex with the resulting C60 cycloadduct facilitates its displacement by pristine C60, which grants catalytic turnover. Moreover, bis‐addition compounds are regioselectively formed inside the cage when using excess anthracene. [ABSTRACT FROM AUTHOR]

Subphthalocyanines (SubPcs) are aromatic chromophores with a bowlshaped structure and outstanding optoelectronic properties. The cavity formed by a C3-symmetry trispyridyl-SubPc, Pd(II)-metalloorganic capsule has proved an optimal, shape-complementary space for the complexation of C60. Taking advantage of the intense green light absorption of the SubPc components of the capsule, and their ability to transfer energy/electrons from the excited state, our group has recently described the unprecedented use of SubPc cages as molecular photoreactors to perform photoredox-triggered addition of diphenylamine radicals over encapsulated C60. Unfortunately, the reaction could only be performed using stoichiometric amounts of the cage due to inhibition of the SubPc cavity by the addition compound. Here, we describe the preparation of a more flexible SubPc cage built with a related C1-symmetry trispyridyl-SubPc (C1-SubPc-cage), which could facilitate the exchange between the complexed addition compound and pristine fullerene, thus allowing to use it in catalytic amounts. After assessing the ability of C1-SubPc-cage to host C60, the addition of α-aminoalkyl radicals in the presence of the cage under green light irradiation was tested. Curiously, optimisation of the reaction conditions (using catalytic amounts of C1-SubPc-cage in diluted solutions) rendered a different reaction outcome, that is, a cyclopropanated fullerene, in remarkably high yields. [ABSTRACT FROM AUTHOR]

Abstract: Z-scan experiments have been performed on solutions of tBu4PcTiO2-C60 (2) in order to explore a plausible synergistic effect. For comparative purposes we have also measured C60 and tBu4PcTiO (1) derivatives. The results indicate poorer excited-state absorption of dyad 2 than those of the corresponding individual phthalocyanine and fullerene components. [Copyright &y& Elsevier]

Herein, we report the synthesis and characterization of new amphiphilic phthalocyanines (Pcs), the study of their singlet oxygen generation capabilities, and biological assays to determine their potential as photosensitizers for photodynamic inactivation of bacteria. In particular, Pcs with an ABAB geometry (where A and B refer to differently substituted isoindole constituents) have been synthesized. These molecules are endowed with bulky bis(trifluoromethylphenyl) groups in two facing isoindoles, which hinder aggregation and favour singlet oxygen generation, and pyridinium or alkylammonium moieties in the other two isoindoles. In particular, two water-soluble Pc derivatives (PS-1 and PS-2) have proved to be efficient in the photoinactivation of S. aureus and E. coli , selected as models of Gram-positive and Gram-negative bacteria. Image 1 • Synthesis of water-soluble ABAB ZnPcs for photodynamic inactivation of bacteria. • Rational design with bis(trifluoromethylphenyl) and cationic substituents in facing isoindoles. • Efficient 1O 2 generation, balanced lipophilicity/hydrophilicity and reduced aggregation. • More efficient photoinactivation of S. aureus and E. coli than other related cationic Pcs. [ABSTRACT FROM AUTHOR]

Pt(II)-BODIPY complexes combine the chemotherapeutic activity of Pt(II) with the photocytotoxicity of BODIPYs. Additional conjugation with targeting ligands can boost the uptake by cancer cells that overexpress the corresponding receptors. We describe two Pt(II) triangles, 1 and 2 , built with pyridyl BODIPYs functionalized with glucose ( 3 ) or triethylene glycol methyl ether ( 4 ), respectively. Both 1 and 2 showed higher singlet oxygen quantum yields than 3 and 4 , due to the enhanced singlet-to-triplet intersystem crossing. To evaluate the targeting effect of the glycosylated derivative, in vitro experiments were performed using glucose transporter 1 (GLUT1)-positive HT29 and A549 cancer cells, and noncancerous HEK293 cells as control. Both 1 and 2 showed higher cellular uptake than 3 and 4 . Specifically, 1 was selective and highly cytotoxic toward HT29 and A549 cells. The synergistic chemo- and photodynamic behavior of the metallacycles was also confirmed. Notably, 1 exhibited superior efficacy toward the cisplatin-resistant R-HepG2 cells.