Journal of Porphyrins and Phthalocyanines

Although photodynamic therapy has been extensively studied in recent years and preclinical studies have shown promising results, strategies for enhancing PDT outcomes and reducing side effects still urgently need to be developed. In this study, a series of Tamoxifen-zinc(II) phthalocyanine conjugates have been designed and synthesized. In these “double-headed” conjugates, photodynamic therapy agent zinc(II) phthalocyanine and hormone therapy drug Tamoxifen were combined via oligoethylene glycol linkers. The conjugates show high specificity, and some of them show cytotoxic effects against the MCF-7 cells overexpressed Estrogen receptor, due to the targeting and cytostatic Tamoxifen moiety. Upon illumination, all these conjugates show high cytotoxicity due to the photosensitizing phthalocyanine unit. Their structure-activity relationship was also assessed. The results show that $\alpha$-substituted Tamoxifen-zinc(II) phthalocyanine conjugates are highly promising anticancer targeting agents which exhibit additive effects of photodynamic therapy and hormone therapy.

The singlet oxygen quantum yields of photosensitizers in different solvents are very important for photodynamic therapy (PDT). Here, we investigated the singlet oxygen quantum yields of tetrakis (4-carboxyphenyl) porphyrin (TCPP) in various solvents by the iodide method. Results indicate that TCPP has different singlet oxygen formation efficiency in different solvents. When compared to TCPP dissolved in water, TCPP showed higher singlet oxygen yields in methanol and ethanol, but lower singlet oxygen yields in DMF under identical conditions. In particular, TCPP rapidly precipitated in acetone after potassium iodide added in the solution. The salting out effect of TCPP by potassium iodide in acetone was confirmed by re-dissolving the precipitation in water and the characteristic absorption of TCPP was measured. The phenomenon of salting out for TCPP in acetone suggests that acetone is not a good solvent for singlet oxygen generation when evaluated by the iodide method.

Dicyanoacetylene, a highly reactive dienophile, readily reacts to form substituted maleonitriles which serve as precursors to soluble tetraazaporphyrins. Unfortunately, dicyanoacetylene is difficult to synthesize in large quantities. We report here a new dicyanoacetylene synthon, 1-bromo-1,2-dicyanoethylene, which is easily made in high yield by reaction of elemental bromine with fumaronitrile and easily purified by vacuum distillation. The resulting 5:1 mixture of geometric isomers reacts with dienes via a Diels–Alder reaction followed by elimination of HBr to give substituted maleonitriles. We demonstrate the utility of these reactions by reporting the synthesis of a novel, soluble tetraazaporphyrin bearing four 1,4-fused cyclohexyl groups on the macrocycle periphery.

Heme catabolism is an important physiological process that converts heme to biliverdin in the presence of heme oxygenase which has an essential role in destroying unwanted heme. Verdohemes, the green iron (II) complexes of the 5-oxaporphyrin macrocycle are produced by oxidative destruction of heme. The main goal of this study is clarification of the central metal effect on stabilization of metal 5-oxaporphyrin molecules. To investigate the role of central metal on geometric and electronic properties of five coordinated verdoheme analogues, the first row transitional metals, including Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn, as the central metal of five-coordinated metal 5-oxaporphyrins were systematically calculated without any symmetry constraint by using the B3LYP as DFT method and the 6-31G basis set in gas and solvent phases. According to the results, the stabilization energy of metal 5-oxaporphyrins increases with atomic mass in the solvent phase more than in the gas phase. By reviewing the properties such as the computed frontier orbital energy, HOMO and LUMO gap energy $(\mathrm{\Delta }\mathrm{\text{E}})$, hardness $(\eta )$, chemical potential $(\mu )$, softness (s) and electrophilicity $(\omega )$, the pharmaceutical use of this compound can be discussed.

REE complexes with cyclic aromatic ligands are ranked as the molecular materials with both electronic functionality and a single-molecule magnet behavior at temperatures lower 80 K. At the temperature close to room, they display a positive magnetocaloric effect (MCE) often comparable with one in ferromagnetics. We were determined MCE during the magnetization of both (5,10,15,20-tetra(4-tert-butylphenylporphinato))ytterbium(III)chloride, (Cl)YbT${}^{\mathrm{\text{t}}}$BuPP and (5,10,15,20-tetraphenylporphinato)ytterbium(III)chloride, (Cl)YbTPP in their aqueous suspensions over the temperature range of 278–320 K and in magnetic fields from zero to 1 T by the direct microcalorimetric method. Specific heat capacity in the solid of (Cl)YbT${}^t$BuPP/(Cl)YbTPP has been directly determined in zero magnetic fields using differential scanning calorimetry. Thermodynamic parameters of ytterbium(III) complexes magnetization namely enthalpy/entropy change was determined. To improve understanding of the correlation between (Cl)YbT${}^t$BuPP/(Cl)YbTPP magnetic properties and its electronic structure, we have compared magnetic behavior of paramagnets studied with those for (Cl)MTPP where M = Gd, Eu, Tm.

In this work, copper phthalocyanine (CuPc) was encapsulated into mesocages of MIL-101(Cr) and MIL-100(Fe) by assembling CuPc’s constitutional fractions using a deep eutectic solvent. The prepared materials, CuPc@MIL-101(Cr) and CuPc@MIL-100(Fe), were characterized by powder X-ray diffraction (PXRD), FT-IR, UV-vis and diffuse reflectance UV (DR-UV) spectroscopies, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ICP-OES spectrometry. The prepared materials were used as heterogeneous catalysts for catalytic epoxidation of styrene with molecular oxygen and also tert-butyl hydroperoxide (TBHP) as oxidants in acetonitrile as a solvent. The impact of MOFs and the role of the CuPc complex as the active species in the MOFs’ cages in the epoxidation of styrene were investigated. Among the prepared catalysts, CuPc@MIL-101(Cr) showed the best performance. The heterogeneity of the catalysts was examined by a hot filtration test and ICP-OES of the filtrates after the reaction. Spent catalysts were analyzed by PXRD, FT-IR, UV-DRS, and TEM for reusability investigation and also to further explore the heterogeneous nature of the hybrid materials. Results showed that the prepared catalysts could be recycled and used for several concoctive times without a considerable drop in activity.

A novel asymmetrical zinc(II) phthalocyanine-BODIPY conjugate (ZnPc-BODIPY) bearing three iodine groups directly substituted to the macrocycle and one BODIPY connected to the macrocycle with an amide bond was synthesized by the reaction of carboxylic-acid-substituted asymmetrical zinc(II) phthalocyanine (ZnPc) with the BODIPY-derivative-bearing amino group (BODIPY-NH₂). This conjugate was fully characterized by spectroscopic methods (FT-IR, UV-vis, ¹H NMR, ¹¹B NMR, ¹⁹F NMR and mass) and elemental analysis. The fluorescence behavior of ZnPc-BODIPY was studied to determine the energy transfer process. Voltammetry measurements (CV and SWV) were performed to specify the HOMO–LUMO energy levels and band gaps of ZnPc-BODIPY and starting compounds (ZnPc and BODIPY-NH₂) for comparison. In addition, the band gaps of these compounds were also determined by UV-vis absorption onset (λ_onset) and theoretical calculations. Bulk heterojunction solar cells containing ZnPc-BODIPY were fabricated in the structure of ITO/PEDOT:PSS/ZnPc-BODIPY:PCBM/Al. The photovoltaic parameters of the solar cell were obtained and the ZnPc-BODIPY conjugate was found to bring spectral contribution to IPCE at a peak of 510 nm.

To investigate the solubility of porphyrin derivatives, their intermolecular interaction energies were calculated by the counterpoise method at the B97D3/6-31G(d) level. It was found that the calculated intermolecular interaction energies corresponded to the solubility measured by UV-vis spectroscopy. This correlation was consistent with differences in substituents and in the metals in the porphyrin core.

We have investigated the possible formation of charge transfer (CT) complexes of metallotetraphenylporphyrins (MTPhP with M = Mn, Fe, Co, Ni and Cu) and metallooctaethylporphyrins (MOEtP with M = Mn, Fe, Co, Ni, Cu and Zn) with the aromatic solvents, namely benzene, chlorobenzene, benzonitrile and toluene, respectively, in the tetrahydrofuran (THF) media. We have carried out energy minimization calculations of the hybrid systems (metalloporphyrins and aromatic solvents) in 1:1 and 1:2 stoichiometry in presence of THF media. We have analyzed the role of metal present in the metalloporphyrin in the formation of complexes for both 1:1 and 1:2 stoichiometry. Our analysis reveals that the MTPhP-solvent hybrid system is more stable compared to the MOEtP-solvent hybrid system.