Formation, photophysics, and photochemistry of cadmium(II) complexes with 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin and its octabromo derivative: The effects of bromination and the axial hydroxo ligand

Valicsek, Zsolt; Horváth, Ottó; Lendvay, György; Kikaš, Ilijana; Škorić, Irena

doi:10.1016/j.jphotochem.2010.12.014

Cited by 32 publications

(48 citation statements)

References 69 publications

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“…All experiments were carried out with aerated systems. The solutions containing metalloporphyrin were prepared well before the photophysical and photochemical experiments (keeping them at 60 45 o C for at least 3 days), so that the onset of complex equilibration was ensured. The actual concentrations of the porphyrin stock solutions prepared were checked spectrophotometrically, using the molar absorptions of the reagents at characteristic wavelengths.…”

Section: Analyticalmentioning

confidence: 99%

“…For determination of the compositions, stability constants, and individual absorption spectra of the complexes formed, experiments were carried out at constant porphyrin concentration, changing the metal ion concentration in the range of 0-6.410 -4 M. 45 Lanthanum(III) ion, as a consequence of its large ionic radius (103.2 pm 42 ), forms typical out-of-plane complexes, which decreases the energy of the intraligand * transitions, i.e. causes red shift of the corresponding bands.…”

Section: Monoporphyrin Complexesmentioning

confidence: 99%

“…Such reactions can be accounted for the high coordination number (8 and 9), which is peculiar to the ions of the f-block elements. In the bisporphyrin complexes the tetradentate ligands generate coordination spheres 45 with 8 position around the metal center with cubic (CU-8) or square antiprism (SAPR-8) symmetry. Although the difference between the stabilities of these two structures is relatively small, the latter one is more characteristic of these complexes.…”

Section: Bisporphyrin Complexmentioning

confidence: 99%

“…[13][14][15][16][17][18] In these species the distortion caused by the outof-plane location of the larger metal center makes two diagonal pyrrolic nitrogens more accessible to another metal ion on the other side of the porphyrin ligand. 19 45 Deviating from the coplanar metalloporphyrins, the OOP complexes, on account of their distorted structure and kinetic lability, display special photochemical properties, such as photoinduced charge transfer from the porphyrin ligand to the metal center, leading to irreversible ring opening of the ligand and 50 dissociation on excitation at both the Soret-and the Q-bands. 20 The absorption and emission features of these complexes also significantly differ from those of the in-plane metalloporphyrins.…”

Section: Introductionmentioning

confidence: 99%

“…This blue shiftred shift anomaly, however, is virtual, because the absorption shift is 65 referred to the average of the Qy(0,0)-and Qx(0,0)-bands of the free-base ligand, while the emission derives not from a hypothetical average level, but from the energetically lower S1x-state (populated in Qx(0,0) absorption). 45 Both phenomena indicate that the structure of the originally flat Since excitation at both the Soret-and the Q-bands leads to the same emission spectrum in the 580-780-nm range, the fluorescence takes place from the same excited state (S1), i.e. excitation to the S2 state is followed by an efficient internal conversion to the S1 state.…”

mentioning

confidence: 98%

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Equilibrium, photophysical and photochemical examination of anionic lanthanum(iii) mono- and bisporphyrins: the effects of the out-of-plane structure

2012

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Lanthanum(III) ion forms kinetically labile complexes with the 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin anion (H2TSPP 4-), the compositions and formation constants of which significantly depend on the presence of potential axial ligands (at 0.01 M). Deviating from the chloride ion, acetate coordinating to the metal center hinders the formation of bisporphyrin complex. In these 10 lanthanum(III) complexes, the metal center, due to its large ionic radius (103.2 pm), is located out of the ligand plane, distorting it. Accordingly, the absorption and fluorescence spectra of these coordination compounds display special properties characteristic of the so-called sitting-atop (SAT) or out-of-plane (OOP) porphyrin complexes. Metalation significantly decreases the quantum yield of the fluorescence from the S1 excited state. Quantum chemical calculations (DFT) confirm the considerable OOP 15 displacement of the La(III) center (about 120 pm in the monoporphyrin complexes). The monoporphyrins display efficient fluorescence (0.03), while the bisporphyrin does not emit. Differing from the normal (in-plane) metalloporphyrins, excitation of these lanthanum(III) porphyrins leads to an irreversible ligandto-metal charge transfer (LMCT) followed by the opening of the porphyrin ring, which is also typical of OOP complexes. Dissociation releasing free-base porphyrin can also be observed upon irradiation of the 20 monoporphyrin in acetate solution, while in the presence of chloride ions interconversions of the monoand bisporphyrins may also take place beside the irreversible photoredox reaction.

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Section: Analyticalmentioning

confidence: 99%

Section: Monoporphyrin Complexesmentioning

confidence: 99%

Section: Bisporphyrin Complexmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 98%

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Equilibrium, photophysical and photochemical examination of anionic lanthanum(iii) mono- and bisporphyrins: the effects of the out-of-plane structure

2012

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Employing Noble Metal–Porphyrins to Engineer Robust and Highly Active Single‐Atom Nanozymes for Targeted Catalytic Therapy in Nasopharyngeal Carcinoma

Wang,

Gao

et al. 2023

Advanced Materials

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Single‐atom nanozymes (SANzymes) emerge as promising alternatives to conventional enzymes. However, chemical instability limits their application. Here, a systematic synthesis of highly active and stable SANzymes is presented by leveraging noble metal–porphyrins. Four noble metal–porphyrins are successfully synthesized to mimic the active site of natural peroxidases through atomic metal–N coordination anchored to the porphyrin center. These noble metal–porphyrins are integrated into a stable and biocompatible Zr‐based metal–organic framework (MxP, x denoting Ir, Ru, Pt, and Pd). Among these, MIrP demonstrates superior peroxidase‐like activity (685.61 U mg−1), catalytic efficiency, and selectivity compared to horseradish peroxidase (267.71 U mg−1). Mechanistic investigations unveil heightened catalytic activity of MIrP arises from its robust H2O2 adsorption capacity, unique rate‐determining step, and low energy threshold. Crucially, MIrP exhibits remarkable chemical stability under both room temperature and high H2O2 concentrations. Further, through modification with (−)‐Epigallocatechin‐3‐Gallate, a natural ligand for Epstein–Barr virus (EBV)‐encoded latent membrane protein 1, targeted SANzyme (MIrPHE) tailored for EBV‐associated nasopharyngeal carcinoma is engineered. This study not only presents an innovative strategy for augmenting the catalytic activity and chemical stability of SANzymes but also highlights the substantial potential of MIrP as a potent nanomedicine for targeted catalytic tumor therapy.

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Advances and perspectives in near‐infrared fluorescent organic probes for surgical oncology

Xü

Chu

et al. 2020

WIREs Nanomed Nanobiotechnol

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Surgical resection of solid tumors is currently the most efficient and preferred therapeutic strategy for treating cancer. Despite significant medical, technical, and scientific advances, the complete treatment of this lethal disease is still a challenging task. New imaging techniques and contrast agents are urgently needed to improve cytoreductive surgery and patient outcomes. Tumor‐targeted probes are valuable for guiding a surgical resection of tumor from subjective judgments to visual inspection. Near‐infrared (NIR) fluorescent imaging is a promising technology in preclinical and clinical tumor diagnosis and therapy. The rapid development in NIR fluorophores with improved optical properties, targeting strategies, and imaging devices has brought about prospective study of novel NIR nanomaterials for intraoperative tumor detection. In this review, we summarize the recent development in NIR‐emitting organic fluorophores and cancer‐targeting strategies that specifically target and accumulate in tumors for the molecular imaging of cancerous cells. We believe this technique utilizing new fluorescent probes with an intraoperative optical imaging capacity could provide a more sensitive and accurate method for cancer resection guidance, thereby resulting in better surgical outcomes. This article is categorized under: Diagnostic Tools > in vivo Nanodiagnostics and Imaging Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

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Formation, photophysics, and photochemistry of cadmium(II) complexes with 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin and its octabromo derivative: The effects of bromination and the axial hydroxo ligand

Cited by 32 publications

References 69 publications

Equilibrium, photophysical and photochemical examination of anionic lanthanum(iii) mono- and bisporphyrins: the effects of the out-of-plane structure

Equilibrium, photophysical and photochemical examination of anionic lanthanum(iii) mono- and bisporphyrins: the effects of the out-of-plane structure

Employing Noble Metal–Porphyrins to Engineer Robust and Highly Active Single‐Atom Nanozymes for Targeted Catalytic Therapy in Nasopharyngeal Carcinoma

Advances and perspectives in near‐infrared fluorescent organic probes for surgical oncology

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