Porphyrin halide ion receptor

Ivanova, Yu. B.; Sheinin, V. B.; Мамардашвили, Н. Ж.

doi:10.1134/s1070363207080270

Cited by 39 publications

(19 citation statements)

References 3 publications

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“…[14,[53][54][55][56][57] For example, the maximum of the 0-0 transition of the uncomplexed DP species of Н 2 ТPP lies at 650-652 nm (depending on the solvent), whereas upon complexation with PF 6 -or Cl -it shifts to 659 and 665 nm, respectively. The maxima in the fluorescence spectra also show a bathochromic shift.…”

Section: Photophysical Properties Of Mono-and Diprotonated Porphyrinsmentioning

confidence: 99%

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Influence of Macrocycle Protonation on the Photophysical Properties of Porphyrins

Kruk¹,

Старухин²,

Maes³

2011

MHC

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Section: Photophysical Properties Of Mono-and Diprotonated Porphyrinsmentioning

confidence: 99%

“…-complexes with halides, [23,26,53,55,57] the bathochromic shift of the spectra increases in the series Cl -> Br -> I -. The fluorescence quenching in the DP .…”

Section: Photophysical Properties Of Mono-and Diprotonated Porphyrinsmentioning

confidence: 99%

Influence of Macrocycle Protonation on the Photophysical Properties of Porphyrins

Kruk¹,

Старухин²,

Maes³

2011

MHC

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“…About 70−80% of absorbance changes are observed within the first stage and the remainder occurs within the second one. Having determined the coordinates of the folding point in the titration curve using a known procedure, 26 the two protonation steps were separated, and the corresponding protonation constants were calculated. The values of the protonation constants for the first (K b1 ) and second (K b2 ) steps were 151 and 41, respectively, with corresponding log K values of 2.18 and 1.6.…”

Section: 23mentioning

confidence: 99%

Corrole NH Tautomers: Spectral Features and Individual Protonation

et al. 2012

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Protonation of a free-base meso-pyrimidinyl-substituted AB 2 -corrole (H 3 AB 2 ) in ethanol solution by stepwise addition of sulfuric acid has been studied in the temperature range from 293 to 333 K. The formation rate of protonated species was found to depend profoundly on the temperature at which the titration was undertaken. Two steps in the titration curve were identified at temperatures around 293−298 K, whereas one-step formation of protonated species was found to occur at temperatures above 308 K. The protonation product was the same in both cases, i.e., H 4 AB 2 + corrole, protonated at the macrocycle core nitrogen atoms. The two steps in the protonation kinetics at lower temperatures were attributed to protonation of individual tautomers of the free-base H 3 AB 2 corrole. To the best of our knowledge, this is the first well-illustrated (spectrophotometric) observation of individual properties of corrole NH tautomers in fluid solution. Concomitant increase in the NH tautomerization rate with increasing temperature is proposed to account for the one-step protonation. Evidences for the role of individual corrole NH tautomers in the protonation process as well as their optical features are discussed based on spectroscopic results and simulation data. ■ INTRODUCTIONCorroles, contracted tetrapyrrolic macrocycles lacking one meso-carbon atom, have emerged as attractive porphyrinoid materials, notably during the past decade, in which novel synthetic pathways toward meso-triaryl-substituted corroles and numerous postmacrocyclization functionalization protocols have considerably enlarged the set of available corrole structures and their potential applications.1,2 Corrole-based materials are nowadays extensively studied as novel catalysts, antitumor treatment, and imaging agents as well as active materials in the design of new sensors and optoelectronic devices. 3,4 Two major structural peculiarities of corroles relative to porphyrins are the presence of three rather than two NH protons in the coordination core and their lower symmetry. The phenomenon of NH tautomerization has been known for a long time for free-base (Fb) porphyrins and has been studied in detail by NMR and optical spectroscopy methods in both the liquid and solid states. 5 The presence of three NH protons in the corrole macrocyclic core and the inherent asymmetry impose many questions concerning the specific details of the corrole tautomerization mechanism. Quantum chemical calculations predict a substantially lower barrier for corrole tautomerization (2.45 kcal mol −1 )6 as compared to that of porphyrins (17 kcal mol −1 ), 7 which leads to a much faster rate of proton migration in the tetrapyrrolic core. The lower symmetry of the Fb corrole macrocycle (C s ) compared to that of a Fb porphyrin (D 2h ) implies that the two tautomeric forms are distinct and structurally quite different (see Scheme 1), which opens the possibility to detect the two NH tautomers for any corrole derivative, independently of the peripheral substitution pa...

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“…Равновесный процесс протонирования порфиринов по внутрициклическим атомам азота (2) изучали согласно описанным в литературе методам. [20,21] Cначальная и текущая концентрации порфирина). Концентрацию порфиринов в ходе эксперимента контролировали по изменению оптической плотности раствора.…”

Section: экспериментальная частьunclassified

Influence of the Ligand’s Basicity on the Kinetics of Complexation of 5,10,15,20-Tetra(trifluoromethyl) and 5,10,15,20-Tetra(iso-butyl)porphine with Copper Acetate

Pukhovskaya¹,

Ivanova²,

Семейкин³

et al. 2018

MHC

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HClO 4 и CH 3 COOH-Cu(ОАc) 2. Установлено, что при титровании лигандов хлорной кислотой в ацетонитриле происходит последовательное протонирование атомов азота пиррольных колец с образованием монои дикатионных форм, электронные спектры поглощения которых могут быть выделены. Определены суммарные константы основности и концентрационные интервалы существования ионизированных форм лигандов в ацетонитриле. Измерены кинетические параметры образования комплексов меди(II). Обсуждено влияние природы заместителей в мезо-положениях порфиринового макроцикла на реакционную способность тетрапиррольных макроциклов.

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Porphyrin halide ion receptor

Cited by 39 publications

References 3 publications

Influence of Macrocycle Protonation on the Photophysical Properties of Porphyrins

Influence of Macrocycle Protonation on the Photophysical Properties of Porphyrins

Corrole NH Tautomers: Spectral Features and Individual Protonation

Influence of the Ligand’s Basicity on the Kinetics of Complexation of 5,10,15,20-Tetra(trifluoromethyl) and 5,10,15,20-Tetra(iso-butyl)porphine with Copper Acetate

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