Porphyrins

Eastwood, DeLyle; Gouterman, Martin

doi:10.1016/0022-2852(69)90276-8

Cited by 85 publications

(33 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…But for metalloporphyrins of D 4h symmetry the polarization of emission showed no such dependence [26]. 2 Having in mind that at longer delay times (i.e. P 500 ps) the decay kinetics for DA k and DA MA should coincide, we used as (DA k À DA MA ) term in Eq.…”

Section: Resultsmentioning

confidence: 99%

“…4 T 1 relaxation kinetics in transient absorption experiments is unlikely because the extinction coefficients of the 2 T 1 and 4 T 1 states should be close to each other. The methods of kinetic luminescence spectroscopy could be more promising for this purpose due to considerable difference in deactivation rates (both radiative and radiationless) for the 2 T 1 and 4 T 1 states [2][3][4]11].…”

Section: Discussionmentioning

confidence: 99%

“…1). The quartet is lower in energy than the tripdoublet by 200-700 cm À1 , depending on the macrocycle, and these two states apparently differ in both radiative and non-radiative rates of deactivation to the ground doublet state [2][3][4].…”

Section: Introductionmentioning

confidence: 98%

“…2;4 T 1 radiationless deactivation [5,6] resulting in very efficient 2;4 T 1 state population (the quantum yield of intersystem crossing c % 0:90 [7]). Secondly, the spectrum, lifetime and quantum yield of the luminescence arising from the tripdoublet-quartet pair are highly temperature dependent [2,4,8,9]. This has been rationalized in terms of (i) temperature dependent relative populations of the 2 T 1 and 4 T 1 states, and (ii) a presence of the low-lying chargetransfer (CT) state, likely of a ring-to-metal (p, d) origin, that quenches the luminescence from the 2 T 1 and 4 T 1 states.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Dichroism of the triplet–triplet transient absorption of copper(II) porphyrins in liquid solution. New interpretation of the subnanosecond relaxation component

Sazanovich

Ganzha

Джагаров

et al. 2003

Chemical Physics Letters

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Dichroism of the triplet–triplet transient absorption of copper(II) porphyrins in liquid solution. New interpretation of the subnanosecond relaxation component

Sazanovich

Ganzha

Джагаров

et al. 2003

Chemical Physics Letters

View full text Add to dashboard Cite

“…The weaker phosphorescence of other metalloporphyrins has been known since 1947 [21]. It can be noted that the phosphorescence quantum yield is close to unity for Pt-porphyrins with alkyl and pseudo-alkyl substituents (PtOAlkP) in the β-positions of the pyrrole rings whereas those for PdOAlkP are slightly lower, e.g., 0.9 and 0.5, respectively, for etioporphyrin complexes [22]. Studies of the influence of structural factors on the phosphorescence showed that reduction of the pyrrole ring increased ΔE ST by ~800 cm -1 for Pd-porphine, by ~1000 cm -1 for PdOAlkP [23], and by 2250 cm -1 for mesotetraazasubstitution on going from Pd-porphine to PdTAP [24].…”

Section: Experimental Synthesis Norborn-5′-eno[b]tetraazachlorin (Hmentioning

confidence: 99%

Spectral-luminescence properties of a norbornene-substituted tetraazachlorin and its metal complexes

et al. 2010

View full text Add to dashboard Cite

The spectral-luminescence properties of a tetraazachlorin derivative with a norbornene fragment annelated to a reduced pyrrole ring and its complexes with zinc and palladium have been studied at 293 and 77 K. For the norbornene-substituted free base, differences in fluorescence from unsubstituted tetraazachlroin and its dibenzobarrelene-substituted analog are found. The fluorescence lifetime is observed to rise by ~7 times for the free base and by ~1.6 ties for the Zn complex on going from 293 to 77 K. An essential dependence of the photophysical parameters on the nature of the solvent is noted. The fluorescence polarization spectrum of the norbornene-substituted tetraazachlorin reveals in the Soret band region at least four electronic transitions. For the Pd complex, weak phosphorescence in the near IR region has been detected; the 0-0 band maximum is at 990 nm and the singlet-triplet interval amounts to 5800 cm -1 , which is larger by 400 cm -1 than for Pd tetraazaporphine. The quantum yields of the photosensitized formation of singlet oxygen have been determined using a relative luminescence method.

show abstract

Quasi-line phosphorescence spectra of the copper complex of meso-tetrapropylporphin at liquid helium temperature

Arabei

Solovyov

Egorova

2000

J. Porphyrins Phthalocyanines

View full text Add to dashboard Cite

Quasi-line spectra of the 4 T 1→2 S 0 phosphorescence of Cu meso-tetrakis(n-propyl)porphin in n-octane at 4.2 K under wide-band and selective excitation have been obtained and analysed. A non-typically large distance between the edge components of the origin ‘multiplet’ (175 cm−1) indicating the sensitivity of the energy of the 0-0 transition of molecular impurity centres to the surroundings has been noted, which can lead to a significant inhomogeneous broadening in amorphous media. Two vibrations with frequencies of about 220 cm−1 are predominantly active in the phosphorescence spectrum. Unlike Cu porphin, the intensity of the corresponding quasi-lines is lower than the intensity of the 0-0 transition. From the broadening of the Q(0-0) band in the phosphorescence excitation spectrum at selective recording of the 0-0 quasi-line the lifetime of the level 2 S 1 (Q) has been determined as 35 fs.

show abstract

Porphyrins

Cited by 85 publications

References 17 publications

Dichroism of the triplet–triplet transient absorption of copper(II) porphyrins in liquid solution. New interpretation of the subnanosecond relaxation component

Dichroism of the triplet–triplet transient absorption of copper(II) porphyrins in liquid solution. New interpretation of the subnanosecond relaxation component

Spectral-luminescence properties of a norbornene-substituted tetraazachlorin and its metal complexes

Quasi-line phosphorescence spectra of the copper complex of meso-tetrapropylporphin at liquid helium temperature

Contact Info

Product

Resources

About