Photophysics and photochemistry of kinetically labile, water-soluble porphyrin complexes

Horváth, Ottó; Huszánk, Róbert; Valicsek, Zsolt; Lendvay, György

doi:10.1016/j.ccr.2006.02.014

Cited by 73 publications

(115 citation statements)

References 33 publications

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“…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%

“…Interestingly, even in the 20 presence of efficient electron donor (NADH, reduced nicotinamide adenine dinucleotide), not the metal center, but the porphyrin ligand (TMPyP 2+ ) was reduced upon irradiation of Lu(III)TMPyP 5+ (H2TMPyP 4+ = tetrakis(4-methyl-4-pyridinium)-porphyrin). 23 However, no observation was published about 25 photoinduced CT reactions between the porphyrin and the metal center, neither dissociations of lanthanide(III) porphyrins.…”

Section: Introductionmentioning

confidence: 99%

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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: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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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“…Metal ions can form in-plane metalloporphyrins, fitting into the cavity of the porphyrin ring, or several of them are located out of the ligand plane, resulting in out-of-plane (OOP or sitting-atop=SAT) complexes with dome-distorted structure, thermodynamic instability, kinetic lability, typical photophysical features, and photochemical reactivity [1,2]. Besides, the OOP position promotes the formation of bis-or oligoporphyrins, so called sandwich complexes, mainly if the metal center is susceptible to higher coordination numbers ( Fig.…”

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confidence: 99%

“…in optical telecommunication, spectral conversion of solar energy, and biomedical optical imaging [11][12][13][14][15][16]. Furthermore, lanthanide(III) porphyrins may be useful in the photocatalytic cleavage of water because the metal center, reduced due to the photoinduced charge transfer from ligand to metal (LMCT) [1,2,17,18], has a negative redox potential large enough to produce hydrogen (except Eu 3+ , Fig. 2) [9].…”

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confidence: 99%

“…However, during the photolysis of early lanthanide(III) porphyrins at the maximum of the Q-bands (~555 nm), a new photoproduct appears, which is stable in dark (Fig. 6) and undetectable in the case of post-transition metal ions' typical OOP complexes [1,2]. The Soretband disappeared as a consequence of the ring-opening reaction; hence, the absorption band at 590 nm may be assigned to a complex between lanthanide(III) and this open-chain, dioxotetrapyrrole derivative (Fig.…”

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Peculiar photoinduced properties of water-soluble, early lanthanide(III) porphyrins

Imran

Szentgyörgyi

Eller

et al. 2015

Inorganic Chemistry Communications

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Water-soluble, early lanthanide(III) mono-and bisporphyrin complexes possess very similar UV-Vis absorption, photophysical and photochemical properties, as a consequence of a special type of aggregation, through the peripheral substituents. In the absence of the bidentate, O-donor acetate ligand, bisporphyrin can form too, which has slightly redshifted and broadened absorption bands, compared to those of the monoporphyrin. Also the bisporphyrin displays a blueshifted and less intense fluorescence, related to the free-base porphyrin. The formation of complexes and the transformation between the mono-and bisporphyrins are very slow reactions in dark at room temperature. These reactions are accelerated by the photolysis of the system; which are considerable by-processes of the photoredox degradation. Depending on the wavelength of irradiation, two types of photoproducts can appear: during the photolysis at the Soret-band, a radical type intermediate can be observed, which disappears in dark. However, during the irradiation at the Q-bands, a new photoproduct appears, which is stable in dark and undetectable in the case of post-transition metal ions' out-of-plane porphyrin complexes.

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Spider Silk/Hemin Biobased Electrets for Organic Phototransistor Memory: A Comprehensive Study on Solution Process Engineering

Hsu,

Yu,

Shen

et al. 2024

Adv Funct Materials

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The escalating environmental impact of pollution and the imperative to reduce carbon emissions have heightened the significance of developing biobased materials from natural biomass for electronic devices. This study investigates the utilization of biofermentation‐produced recombinant spider silk and animal‐derived hemin to create a novel biobased electret for field‐effect transistor memory. A critical challenge arises from the incompatibility between natural photoresponsive molecules and insulating biomaterials, resulting in severe phase separation that compromises film quality and morphology uniformity. This study systematically examines the effects of various film deposition and manufacturing techniques on the biobased electret's morphology, phase separation, and performance. Different methods demonstrate distinct advantages in terms of molecular aggregation/segregation, morphological homogeneity, and device performance. Phototransistor memory devices fabricated using spin coating and spray coating techniques exhibit robust aggregations and high memory windows of ≈30 V. Conversely, devices produced through solution shearing and electrospinning methods display enhanced smooth morphologies and high photoresponsivity. The phototransistor memory comprising electrospun fibers holds the potential to achieve the highest memory ratio, reaching ≈105. These findings not only highlight the applications of biobased materials through scalable film deposition processes but also underscore the importance of refining their morphology, phase separation, and performance in optoelectronic devices.

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Photophysics and photochemistry of kinetically labile, water-soluble porphyrin complexes

Cited by 73 publications

References 33 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

Peculiar photoinduced properties of water-soluble, early lanthanide(III) porphyrins

Spider Silk/Hemin Biobased Electrets for Organic Phototransistor Memory: A Comprehensive Study on Solution Process Engineering

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