On the structure of unsolvated free-base 5,10,15,20-tetra(3-pyridyl)porphyrin

Seidel, Rüdiger W.; Goddard, Richard; Hoch, Constantin; Breidung, Jürgen; Oppel, Iris M.

doi:10.1016/j.molstruc.2010.11.011

Cited by 12 publications

(9 citation statements)

References 36 publications

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“…As observed for meta -TPyP [ 61 ] the [ meta -TMPyP ] 4+ fragment was also found in the ααββ conformation in the solid state. The dihedral angles between a calculated mean plane of the C 20 N 4 porphyrin macrocycle and the pyridyl rings were 71.4(1)° and 73.6(1)° ( Figure S4 ) and thus substantially larger compared to the ones of meta -TPyP for which 62.63(7)° and 64.63(6)° have been reported [ 61 ]. On the contrary, for meta -TPyP a slight wave distortion of the porphyrin macrocycle was observed (r.m.s.…”

Section: Resultssupporting

confidence: 62%

The Meta-Substituted Isomer of TMPyP Enables More Effective Photodynamic Bacterial Inactivation than Para-TMPyP In Vitro

et al. 2022

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Porphyrinoid-based photodynamic inactivation (PDI) provides a promising approach to treating multidrug-resistant infections. However, available agents for PDI still have optimization potential with regard to effectiveness, toxicology, chemical stability, and solubility. The currently available photosensitizer TMPyP is provided with a para substitution pattern (para-TMPyP) of the pyridinium groups and has been demonstrated to be effective for PDI of multidrug-resistant bacteria. To further improve its properties, we synthetized a structural variant of TMPyP with an isomeric substitution pattern in a meta configuration (meta-TMPyP), confirmed the correct structure by crystallographic analysis and performed a characterization with NMR-, UV/Vis-, and IR spectroscopy, photostability, and singlet oxygen generation assay. Meta-TMPyP had a hypochromic shift in absorbance (4 nm) with a 55% higher extinction coefficient and slightly improved photostability (+6.9%) compared to para-TMPyP. Despite these superior molecular properties, singlet oxygen generation was increased by only 5.4%. In contrast, PDI, based on meta-TMPyP, reduced the density of extended spectrum β-lactamase-producing and fluoroquinolone-resistant Escherichia coli by several orders of magnitude, whereby a sterilizing effect was observed after 48 min of illumination, while para-TMPyP was less effective (p < 0.01). These findings demonstrate that structural modification with meta substitution increases antibacterial properties of TMPyP in PDI.

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Section: Resultssupporting

confidence: 62%

The Meta-Substituted Isomer of TMPyP Enables More Effective Photodynamic Bacterial Inactivation than Para-TMPyP In Vitro

et al. 2022

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“…It is known that tetraphenylporphyrins and their derivative analogues are characterized by the existence of dimers formed as a result of conjugation of a phenyl hydrogen atom and a π‐system of fragments A, C or B (D) [27] . Due to differences in the geometric structure, atomic composition, and electron density of fragments A, C, and B (D) of HOPP , HSPP , and S 2 PP molecules, the bond strength of dimeric forms is also different.…”

Section: Resultsmentioning

confidence: 99%

First Sublimation Thermodynamics and First Gas‐Phase Experimental Molecular Structure of Heteroporphyrins: 5,10,15,20‐Tetraphenyl‐21‐X, 23‐Y‐Porphyrins (X=O or S; Y=N or S)

Kuzmin,

Shlykov,

Krasnov

et al. 2024

ChemistrySelect

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First sublimation enthalpies of heteroporphyrins: 10,15,20‐tetraphenyl‐21‐oxa‐ (HOPP), 5,10,15,20‐tetraphenyl‐21‐thia‐ (HSPP) and 5,10,15,20‐tetraphenyl‐21,23‐dithia‐ (S2PP) were measured by Knudsen effusion mass spectrometry: ΔsublH (T)=209±2 (561 K), 224±2 (552 K) and 219±2 (577 K) kJ/mol, respectively. Geometry and force field of a free molecule of HSPP was studied by quantum chemistry, and first gas‐phase experimental molecular structure of heteroporphyrins was derived by gas‐phase electron diffraction. Theoretically observed changes of the coordination cavity geometries due to heteroatomic intracavity substitution were experimentally confirmed with good agreement. Molecular structures of the dimeric associates of the heteroporphyrins were tested simulated to reveal tendencies in sublimation thermodynamics.

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“…In the same manner, the highest HER catalytic activity can also be expected in an alkaline solution for the electrode covered with Zn-porphyrin because the four pyridyl groups grafted on the porphine ring are stable in this medium, but generate pyridinium N + H in an acidic environment, thus promoting dimerization and an undesired uniform and compact self-aggregation due to London’s dispersion force being the main binding force [ 71 ]. In addition, the positional disorder of the pyrrole NH atoms was demonstrated in pyridyl-substituted porphyrins [ 72 ] in normal and basic pH. Instead, the distorted porphyrin molecules obtained in acidic medium by the protonation of the N-pyridyl groups were packed more efficiently in adjacent stacks because of the weak C–H…N hydrogen bonds formed between β-pyrrole moieties and the pyridyl groups of the molecules.…”

Section: Resultsmentioning

confidence: 99%

The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins

Țăranu

Fagadar‐Cosma

2022

Nanomaterials

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Hydrogen, considered to be an alternative fuel to traditional fossil fuels, can be generated by splitting water molecules into hydrogen and oxygen via the use of electrical energy, in a process whose efficiency depends directly on the employed catalytic material. The current study takes part in the relentless search for suitable and low-cost catalysts relevant to the water-splitting field by investigating the electrocatalytic properties of the O2 and H2 evolution reactions (OER and HER) of two metalloporphyrins: Zn(II) 5,10,15,20-tetrakis(4-pyridyl)-porphyrin and Co(II) 5,10,15,20-tetrakis(3-hydroxyphenyl)-porphyrin. The TEM/STEM characterisation of the porphyrin samples obtained using different organic solvents revealed several types of self-assembled aggregates. The HER and OER experiments performed on porphyrin-modified graphite electrodes in media with different pH values revealed the most electrocatalytically active specimens. For the OER, this specimen was the electrode manufactured with one layer of Co-porphyrin applied from dimethylsulfoxide, exhibiting an overpotential of 0.51 V at i = 10 mA/cm2 and a Tafel slope of 0.27 V/dec. For the HER, it was the sample obtained by drop casting one layer of Zn-porphyrin from N,N-dimethylformamide that displayed a HER overpotential of 0.52 V at i = −10 mA/cm2 and a Tafel slope of 0.15 V/dec.

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On the structure of unsolvated free-base 5,10,15,20-tetra(3-pyridyl)porphyrin

Cited by 12 publications

References 36 publications

The Meta-Substituted Isomer of TMPyP Enables More Effective Photodynamic Bacterial Inactivation than Para-TMPyP In Vitro

The Meta-Substituted Isomer of TMPyP Enables More Effective Photodynamic Bacterial Inactivation than Para-TMPyP In Vitro

First Sublimation Thermodynamics and First Gas‐Phase Experimental Molecular Structure of Heteroporphyrins: 5,10,15,20‐Tetraphenyl‐21‐X, 23‐Y‐Porphyrins (X=O or S; Y=N or S)

The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins

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