Photophysical properties of mesonitrophenyl-substituted porphyrins and their dimers at 295 K

Knyukshto, V. N.; Zenkevich, É. I.; Sagun, E. I.; Шульга, А. М.; Bachilo, Sergei M.

doi:10.1007/bf02675391

Cited by 8 publications

(25 citation statements)

References 11 publications

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“…The phosphorescence of PdOEP-Ph is strongly quenched compared to that of PdTMDEP-Ph (by a factor of 350). According to the results of our studies [13,14], this quenching is related to the nonstationary nonplanarity of the porphyrin macrocycle in the excited T 1 state. The search for new bands in the spectral region up to 1100 nm at 293 K performed in this paper did result in the detection of the phosphorescence bands belonging to the nonplanar conformation of PdOEP-Ph molecules.…”

Section: Absorption and Luminescence Spectramentioning

confidence: 57%

“…In the case of mono-mesophenyl-substituted PdOEP-Ph, a passage to rigid matrices at 77 K eliminates the conformation dynamics of the π-conjugated macrocycle in the T 1 state caused by the steric interaction of volume substituents [13,14]. As a result, the phosphorescence spectra detected under these conditions coincide with those of PdOEP and PdTMDEP-Ph (see Fig.…”

Section: Absorption and Luminescence Spectramentioning

confidence: 83%

“…Such an approach was used for studying PET from the T 1 state in covalently bonded complexes of Pd-tetraphenylporphyrin-quinone (PdTPP-Q) in toluene at 293 K [19]. We have shown that efficient PET (the probability = 9.5 × 10 9 s -1 in toluene at 293 K) occurs from the excited S 1 states of steric hindered meso-ortho-nitrophenyloctaetylporphyrins and their chemical dimers to the NO 2 group, which can be described by the Marcus theory for nonadiabatic electron transfer [20][21][22]. The study of Pd complexes of these compounds is of interest from the point of view of the elucidation of mechanisms of PET involving triplet states.…”

Section: Manifestation Of Nonplanarity Effects and Charge-transfer Inmentioning

confidence: 99%

“…We showed recently [12][13][14] that the introduction of volume substituents into the ortho position of the phenyl ring of β-alkyl-substituted porphyrins (a passage from OEP-Ph to OEP-Ph(o-CH 3 )) substantially increases steric interactions and hinders torsion vibrations of mesophenyl around a singular C-C bond. In this case, unlike OEP-Ph, the OEP-Ph(o-CH 3 ) molecule remains planar in the excited T 1 state and has a long lifetime in degassed solutions at 293 K. Taking into account these facts, the presence of the long-wavelength band at 1000 nm in the T-T absorption spectrum of the OEP-Ph molecule should be related to the dynamic nonplanarity of the porphyrin macrocycle.…”

Section: Induced Absorption Spectramentioning

confidence: 99%

“…Recently we found [12][13][14] that the introduction of even one phenyl ring into the meso position of β -alkylsubstituted porphyrins [octaethylporphyrins (OEPs), ethioporphyrin II, and their Zn complexes] results in a drastic shortening of τ T at room temperature in liquid solutions and virtually does not affect the spectral and kinetic parameters of the S 1 state decay. We showed in these papers that this effect is related to torsion vibrations (librations) of the phenyl ring around a single C-C bond in porphyrins with the steric hindrance.…”

Section: Introductionmentioning

confidence: 99%

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Manifestation of nonplanarity effects and charge-transfer interactions in spectral and kinetic properties of triplet states of sterically strained octaethylporphyrins

et al. 2001

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-Properties of the triplet states of octaethylporphyrins with the steric hindrance (free bases and Pd complexes) are studied by the methods of stationary and kinetic spectroscopy in the temperature range from 77 to 293 K. The mono-mesophenyl substitution results in a decrease in the quantum yield and shortening of the phosphorescence lifetime of Pd complexes by 250-3500 times in degassed toluene at 293 K. The phosphorescence quenching is caused by nonplanar dynamic conformations of the porphyrin macrocycle in the T 1 state, which also lead to the appearance of new bands at λ ~ 1000 nm in the T -T absorption spectra. As the number of meso-phenyls (Pd-octaetyltetraphenylporphyrin) increases, the quantum yield of phosphorescence further decreases ( <10 -5 ) at 293 K, the lifetime of the T 1 state shortens (<50 ns), and the efficiency of the singlet oxygen generation abruptly decreases (<0.01). The intense bathochromic emission of this compound at 705 nm with a lifetime of 1 ms at 77 K is assigned to the phosphorescence of a nonplanar conformation. Upon meso-orthonitrophenyl substitution, the quenching of phosphorescence of Pd complexes (by more than 10 4 times at 293 K) is caused by direct nonadiabatic photoinduced electron transfer from the T 1 state to the nearest charge-transfer state with the probability = (1.5-4.0) × 10 6 s -1 . The induced absorption of ortho-nitro derivatives in the region between 110 and 1400 nm is caused by mixing of pure ππ * states with charge-transfer states. © 2001 MAIK "Nauka/Interperiodica".

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Section: Absorption and Luminescence Spectramentioning

confidence: 57%

Section: Absorption and Luminescence Spectramentioning

confidence: 83%

Section: Manifestation Of Nonplanarity Effects and Charge-transfer Inmentioning

confidence: 99%

Section: Induced Absorption Spectramentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Manifestation of nonplanarity effects and charge-transfer interactions in spectral and kinetic properties of triplet states of sterically strained octaethylporphyrins

et al. 2001

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ChemInform Abstract: Photophysical Properties of meso‐Nitrophenyl‐substituted Porphyrins and Their Dimers at 295 K

Knyukshto¹,

Zenkevich²,

Sagun³

et al. 2000

ChemInform

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Gallium(III) Corrole Complexes as Near‐Infrared Emitter – Synthesis, Computational and Photophysical Study

et al. 2021

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We report on the chemical synthesis and characterization of free‐base A2B‐ and A3‐meso‐TIPS ethynyl corroles, which serve as a precursor for metalation with gallium(III)chloride and subsequent in‐situ sila Sonogashira cross‐coupling reaction. Under ambient conditions and with a common catalyst system the reaction with different aryliodides proved to be successful. Compared to the well‐known Ga(III)‐pyr‐5,10,15‐trispentafluorophenylcorrole complex, the emission wavelengths of such gallium(III) corroles complexes could be shifted bathochromically by up to ∼3100 cm−1 to the near‐infrared region (NIR). The described synthetic procedure establishes a facile way to obtain organic near‐infrared‐emitters based on gallium(III) meso‐aryl‐ethynyl corrole complexes.

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Photophysical properties of mesonitrophenyl-substituted porphyrins and their dimers at 295 K

Cited by 8 publications

References 11 publications

Manifestation of nonplanarity effects and charge-transfer interactions in spectral and kinetic properties of triplet states of sterically strained octaethylporphyrins

Manifestation of nonplanarity effects and charge-transfer interactions in spectral and kinetic properties of triplet states of sterically strained octaethylporphyrins

ChemInform Abstract: Photophysical Properties of meso‐Nitrophenyl‐substituted Porphyrins and Their Dimers at 295 K

Gallium(III) Corrole Complexes as Near‐Infrared Emitter – Synthesis, Computational and Photophysical Study

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