Intramolecular Interactions in the Ground and Excited States of Tetrakis(N-methylpyridyl)porphyrins

Vergeldt, Frank J.; Koehorst, R.B.M.; Hoek, A. van; Schaafsma, T.J.

doi:10.1021/j100013a007

Cited by 178 publications

(192 citation statements)

References 3 publications

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“…The estimated values of the dimerization constants are presented in Table 1. The range of the dimerization constants is the same to that known from the literature for water solution [35,36]. Values of the dimerization constants from Table 1 are insignificantly decreasing along with the time of monolith samples drying.…”

Section: Discussionsupporting

confidence: 57%

Spectroscopic characterization of water-soluble cationic porphyrins in sol–gel silica matrices and coatings

Dargiewicz¹,

Makarska²,

Radzki³

2002

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Silica aeorogels doped with different concentrations of water-soluble cationic porphyrins were synthesised by the sol-gel polymerisation of tetraethylorthosilicate (TEOS). Porphyrin dimer formation in sol-gel matrices was studied in the function of gelation time, over the porphyrin concentration range up to 10 − 5 M. The deviation from the linearity of Beer-Lambert law starts with porphyrin concentration about 5 ×10 − 6 M. The dimerization constants were estimated. The similar dependence could be observed for the aerogels and the solid thin films.

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Section: Discussionsupporting

confidence: 57%

Spectroscopic characterization of water-soluble cationic porphyrins in sol–gel silica matrices and coatings

Dargiewicz¹,

Makarska²,

Radzki³

2002

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…However, in our experimental results, we did not observe any significant dependence of st on f. The changes in the TMPyP absorption and fluorescence spectra due to variations of the solvent polarity could be associated with charge transfer (CT) between the porphyrin core and lateral groups, which contributes to the formation of their lowest absorption maximum [32][33][34]. However, when CT transitions do occur at the change of the environment polarity, the absorption and fluorescence spectra appear significantly shifted [35] while in our experiments we have observed just a weak effect of solvent polarity on the TMPyP spectra.…”

Section: Tablementioning

confidence: 56%

“…The intersystem crossing and internal conversion quantum yields were calculated as ϕ isc = S 1 / isc and ϕ ic = 1 − (ϕ isc + ϕ F ), respectively. We have observed a reduction of the 34 value and an increase of isc and ic in organic and micellar solutions, as compared with aqueous ones, while both ϕ isc and ϕ ic remained practically unchanged.…”

Section: Tablementioning

confidence: 67%

“…The larger Stokes shift in water, compared to that of organic solvents, can be associated to a higher f in water. It can also be associated to the solvent polarity effect on the CT transition, as proposed in the literature [32][33][34]. However, the increase of environment polarity generally induces a red shift of the CT absorption band [35].…”

Section: Tablementioning

confidence: 82%

“…This procedure provides the 12 values given in Table 1, which are very close for all samples studied. In order to determine the T 1 state cross-sections, 34 , and the S 1 → T 1 intersystem crossing lifetimes, isc , we used the pulse train Z-scan technique. Fig.…”

Section: Tablementioning

confidence: 99%

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Effects of environment on the photophysical characteristics of mesotetrakis methylpyridiniumyl porphyrin (TMPyP)

Gonçalves

Franzen

Corrêa

et al. 2011

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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Electrospray mass spectrometry of isomeric tetrakis(N-alkylpyridyl)porphyrins and their manganese(III) and iron(III) complexes

Batinić‐Haberle

Stevens

Fridovich

2000

J. Porphyrins Phthalocyanines

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Manganese(III) complexes of isomeric tetrakis(N-alkylpyridyl)porphyrins (N- alkyl = N- methyl , M or N- ethyl , E ), MnTM ( E )-2(3,4)- PyP 5+, are being developed as superoxide dismutase (SOD) mimics. Simultaneously, techniques for their purification, identification and characterization are being pursued. Electrospray mass spectrometry ( ESMS ) proved to be an excellent method for identification and characterization of this group of water-soluble cationic porphyrins. The multiply charged parent ion is observed for both the metal-free ligands and their corresponding manganese complexes. The other major peaks in the mass spectra result from loss of N-alkyl groups, reduction of the metal center, axial coordination of chloride or hydroxo ion in the case of the Fe porphyrin, loss of metal and deprotonation of pyrrolic nitrogens. As a result of inductive and resonance effects, which stabilize the ortho isomer, almost no loss of N-alkyl groups from the manganese complex or from its parent ligand was observed. The relative intensity of the multiply charged molecular ion Mn III TM -3(4)- PyP 5+/5 was 100% in the case of the meta and para isomers. Although manganese porphyrins display a low preference toward axial ligation, favorable electrostatics at the metal center of the ortho isomer gives rise to 100% relative intensity of the species that has chloride axially ligated at the manganese site, Mn III TM ( E )-2- PyPCl 4+/4. When the stronger preference of iron porphyrins toward axial ligation combines with the ortho effect, the monohydroxo iron porphyrin Fe III TM -2- PyP ( OH )4+/4 dominates the ESMS of an aqueous acetonitrile solution at pH 7.8.

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Intramolecular Interactions in the Ground and Excited States of Tetrakis(N-methylpyridyl)porphyrins

Cited by 178 publications

References 3 publications

Spectroscopic characterization of water-soluble cationic porphyrins in sol–gel silica matrices and coatings

Spectroscopic characterization of water-soluble cationic porphyrins in sol–gel silica matrices and coatings

Effects of environment on the photophysical characteristics of mesotetrakis methylpyridiniumyl porphyrin (TMPyP)

Electrospray mass spectrometry of isomeric tetrakis(N-alkylpyridyl)porphyrins and their manganese(III) and iron(III) complexes

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