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1.
V. V. Sapunov 《Journal of Applied Spectroscopy》1998,65(6):898-905
Concentration quenching of the triplet state (CQTS) of a number of Pd-porphyrins in toluene is investigated. Based on an analysis
of experimental results, a conclusion is drawn that such quenching proceeds via formation of exciting complexes from molecules
in the ground and triplet states (TS). From a small value of decay rate constants of the complexes it follows that these complexes
are triplet excimers but not complexes due to collision. It is established that by increasing the concentration of porphyrins
the maxima of their phosphorescence bands shift toward large wavelengths by a value of up to 3 nm and the bands, as a consequence,
broaden by 5–7 nm. The formation of excimers is explained by enhancement of solvophobic dispersion interactions of molecules
in the TS. Relatively small changes in the phosphorescence spectra upon formation of excimers are attributable to these interactions.
The magnitude of dipole-dipole interaction of molecules in the TS is insignificant since the dipole moment of the T↭S transition
is small. On the basis of consideration of the oxidation-reduction and energy characteristics of the compounds, it is shown
that the interaction with charge transfer in the case of the CQTS of Pd-porphyrins is inefficient.
Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 857–863, November–December, 1998. 相似文献
2.
L. V. Levshin G. A. Ketsle G. V. Mel’nikov Yu. D. Lantukh 《Journal of Applied Spectroscopy》1997,64(5):639-641
Investigation of deactivation processes in triplet states of a series of aromatic hydrocarbon molecules (antracene, 1,2-benzantracene,
and 3,4-benzpyrene) made it possible to reveal the presence of triplet-triplet annihilation of the molecules in aqueous micellar
solutions of sodium dodecyl sulfate. It is shown that the effect of microheterogeneous solutions on the process of triplet-triplet
annihilation manifests itself in an increase in the probability of excimerization upon dissociation of triplet pairs of 1,2-benzantracene
and 3,4-benpyrene molecules compared to one-component solutions.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 626–628, September–October, 1997. 相似文献
3.
We have pioneered a method of determining the rate constant of quenching of the excited electronic states of molecules by
molecular oxygen from measurements of the kinetics of photosensitized luminescence of singlet molecular oxygen (lδg). The method can be used in the case where the lifetime of the excited electronic state in an air-saturated solution is comparable
with or larger than the luminescence time of the singlet molecular oxygen in the given solvent. It is shown that this situation
is implemented on quenching, by molecular oxygen, of the excited triplet states associated with the biopolymers of tetrapyrrole
molecules in aqueous (H2O and D2O) solutions.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 3, pp. 401–404, May–June, 2000. 相似文献
4.
Time-resolved moderated luminescence of aromatic ketones (benzophenone, aceptophenone) in the presence of neutral and reactive
hydrogeneous foreign gases (ethylene, pentane, triethylamine) is investigated. It is shown that the addition of hydrogeneous
foreign gases leads to strong quenching of the triplet molecules of aromatic ketones. Effectivenesses of such bimolecular
processes as the collision detachment of a hydrogen atom and establishment of vibrational and thermal equilibrium are compared.
It is concluded that the vibrational degrees of freedom of the acceptors, the aromatic ketones, are inactive in the photochemical
process of collision detachment of a hydrogen atom that takes place after the establishment of vibrational equilibrium.
Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 1, pp. 73–77, January–February, 1999. 相似文献
5.
S. L. Bondarev 《Journal of Applied Spectroscopy》1997,64(1):1-15
A review of data on the photophysics of carotenoids is presented. Results of investigations of spectroscopic, temporal, and
energy parameters of excited S1 and S2 singlet states of β-carotene and related compounds are critically examined. These states give rise to extremely high probabilities
(1011–1013 sec−1) of radiationless deactivation of the electronic excitation energy in carotenoids. Results of investigations of photophysical
properties of triplet states of carotenoids are considered mainly from the standpoint of quenching of singlet oxygen and triplet
states of organic molecules by carotenoids.
Institute of Molecular and Atomic Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 5–19, January–February, 1997. 相似文献
6.
I. G. Samusev V. V. Bryukhanov A. M. Ivanov I. S. Labutin B. A. Loginov 《Journal of Applied Spectroscopy》2007,74(2):230-236
We have studied exchange resonance processes of homogeneous triplet-triplet annihilation and heterogeneous triplet-triplet
annihilation for erythrosine and anthracene molecules on an anodized aluminum surface over a broad temperature range. We have
shown that the kinetics of the considered processes are determined by the dimensionality of the molecular clusters on the
porous anodized aluminum surface.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 205–210, March–April, 2007. 相似文献
7.
We have studied the temperature dependence of the radiative deactivation of the Pd-porphine triplet states in Shpol’skii matrices
in the temperature range 1.2–210 K. A substantial transformation of the phosphorescence spectra is observed as the temperature
increases and is due to the inclusion of thermally activated Pd-porphine states in the radiative deactivation processes. The
activation energy Ea of these Pd-porphine states is measured in matrices of n-octane and n-nonane. The splitting of the lowest quasidegenerate
triplet state ΔE(T2−T1) is determined for planar and distorted conformations of the Pd-porphine macrocycle in the n-octane matrix as 40 and 57 cm−1, respectively. The ability to use the temperature dependence of the phosphorescence properties of Pd-porphine to fabricate
molecular thermometers for the low-temperature range is analyzed.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 460–464, July–August, 2007. 相似文献
8.
N. N. Gadzhieva 《Journal of Applied Spectroscopy》2005,72(4):471-477
Using the method of reflection-absorption infrared spectroscopy (RAS), the laws of thermal, radiation-thermal, and radiation
transformations of water on an aluminum surface have been investigated. It has been found that water radiolysis in the Al-adsorbed
water heterosystem is followed by the formation of surface hydroxides and hydrides and molecular hydrogen, as well as by the
formation of an oxide film on the Al surface. The kinetics of aluminum oxidation by water and accumulation of molecular hydrogen
(H2) under the action of γ-radiation at temperatures of 300–900 K has been investigated. It has been shown that as the temperature
of the aluminum-water contact is increased to T ≤ 873 K, there is an increase in the rates of the surface processes of oxidation
and accumulation of H2. On the basis of the results obtained, mechanisms of the processes are proposed.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 440–445, July–August, 2005. 相似文献
9.
V. V. Sapunov 《Journal of Applied Spectroscopy》2000,67(3):405-411
Using the method of pulse photolysis, we studied the quenching of the triplet state (TS) of a number of tetrapyrrole molecules
by complexes of Ni-, Ag-, and Fe-porphyrins in liquid solutions at a temperature of ∼298 K under the conditions where the
kinetics are markedly affected by the triplet-triplet annihilation of the molecules of energy donors. In the analysis of experimental
data, derivatives for the time dependences of the optical density of the triplet-triplet absorption were determined. The triple-triplet
annihilation process was considered for the case of the formation of excited a triplet-triplet complexes of two molecules
in the triplet state. A procedure of determining the rate constant for the quenching of the triplet state by foreign molecules
(Kq) under the effect of such triplet-triplet annihilation process is proposed and the values of Kq are obtained. For some donor-quencher pairs it is found that the kinetics of the triplet-state deactivation are affected
by the formation of short-lived particles with lifetimes both shorter and longer than the triplet-state lifetimes. The conclusion
is drawn that such particles are respectively the excited complexes of interacting molecules or ion radicals formed from such
complexes in polar solvents.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 3, pp. 296–300, May–June, 2000. 相似文献
10.
A. A. Sukhodola 《Journal of Applied Spectroscopy》2008,75(4):527-531
Spectral and kinetic characteristics of delayed luminescence of indole derivatives in the gas phase have been studied. The
mechanism for delayed luminescence has been shown to depend on the disposition of the two lowest excited singlet ππ*-states,
1La and 1Lb. For vapors of 3-methyl-and 2,3-dimethylindole having a small 1La-2Lb energy gap ΔE (ΔE < 500 cm−1), prolonged light emissions with maxima at 525 and 540 nm, respectively, have been observed and interpreted as luminescence
of free radicals formed due to dissociation of an N-H bond. For vapors of 5-methoxyindole having ΔE ≈ 3700 cm−1, annihilation of delayed luminescence has been observed. The lifetimes for triplet states of 3-methyl-, 2,3-dimethyl-, and
5-methoxyindole at T = 373 K equal to 30, 26, and 65 μsec, respectively, were calculated from the kinetics of the delayed
luminescence.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 4, pp. 503–508, July–August, 2008. 相似文献
11.
Photoinduced electron transfer (PET) was studied in toluene solutions of the Pd-porphyrin-quinone (Pd-PQ) dyad by flash photolysis
in the picosecond time range and by a luminescence method. It is found that Pd-PQ has a high rate of intercombination conversion
Kisc=(7.7±0.2)·1010 sec−1. Competing intramolecular PET occurs from the lower excited singlet state of the dyad with the rate constant K
et
s
=(2.7 ±0.3)·1010 sec−1. Therefore, ∼74% of excited molecules from the dyad make a transition to the triplet T1 state and 26% take part in intramolecular PET resulting in formation of radical products. The radical products relax to the
ground state with the rate constant K=(7.4±0.2)·109 sec−1.
Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus, 70, F. Skorina St., Minsk, 220072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 1, pp. 11–18, January–February, 1999. 相似文献
12.
V. V. Vasil'ev I. A. Blinova I. V. Golovina S. M. Borisov 《Journal of Applied Spectroscopy》1999,66(4):583-587
Consideration is given to phosphorescence and photochemical properties of the coordination compounds Pt(II), Pd(II), and Rh(III)
with three water-soluble porphyrins, i.e., meso-tetrakis (4-N,N,N-trimethylaminophenyl) porphin (H2TTMAP4+), meso-tetrakis (4-N-methylpyridyl) porphin (H2TMPyP4+) and meso-tetrakis (4-sulfonatophenyl) porphin (H2TSPP4−). It is shown that the process of photoreduction by an irreversibly oxidized electron donor (EDTA) proceeds only for the
complexes with TMPyP, which is attributed to the strongest oxidative properties of these metal poprhyrins in the triplet excited
state. The end products of the photoreduction reaction (metal chlorins and metallophlorin-anions) are established and its
possible mechanism is suggested.
To whom correspondence should be addressed.
Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998.
A. I. Gertsen Russian State Pedagogical University, 48, Moika Embankment, St. Petersburg, 191186, Russia. Translated from
Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 528–531, July–August, 1999. 相似文献
13.
N.?A.?Borisevich A.?L.?Ivanov S.?M.?Kazakov A.?V.?Kukhto A.?I.?Mit'kovets D.?V.?Murtazaliev V.?A.?Povedailo O.?V.?Khristoforov 《Journal of Applied Spectroscopy》2005,72(4):503-508
The electron energy loss spectra (EELS) of indole, 3-indolyl propionic acid, 3-indolealdehyde, 3-dimethylaminomethylindole,
tryptophan, and N-acetyl-L-tryptophan in the gas phase upon excitation by monokinetic electrons with an energy of E0 = 11–50 eV are obtained. The structure of EELS is determined in the main by the indole chromophore; the side groups, except
for the C=O group of 3-indolealdehyde, exert an insignificant influence. The energy of the lower triplet level 3La is 3.3 eV for indole and its derivatives and 3.2 eV for tryptophan and N-acetyl-L-tryptophan. Four singlet transitions in
the region of 4.4–7.2 eV have been identified. The molecules studied, except for tryptophan, fluoresce in the gas phase on
excitation by electrons. At low values of E0 (10–25 eV), the fluorescence spectra are similar and are due to the indole fluorophore. Just as in the case of optical excitation,
fluorescence on excitation by electrons is associated with the 1Lb-S0 transitions. An increase in the energy E0 up to 60–80 eV leads to dissociation of a portion of the indole molecules and to the appearance of additional bands in the
fluorescence spectrum.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 468–472, July–August, 2005. 相似文献
14.
N. A. Borisevich A. A. Sukhodola G. B. Tolstorozhev 《Journal of Applied Spectroscopy》2007,74(3):379-384
We have studied the spectral characteristics and the kinetics of delayed (long-lived) luminescence of N-methylindole and indole
in the gas phase. For N-methylindole, we observed delayed annihilation fluorescence, spectrally matching fast fluorescence.
There is no delayed annihilation fluorescence for indole, but we observed a delayed luminescence band with wavelength at the
maximum 535 nm, which we interpreted as luminescence of free radicals formed as a result of dissociation of the N-H bond.
We hypothesize that the excited states of the free radicals arise as a result of nonradiative energy transfer from indole
in the triplet state to indole free radicals in the doublet state. The lifetimes of the triplet states of N-methylindole and
indole in the gas phase at T = 373 K, obtained from analysis of the delayed luminescence kinetics, are 2.5 msec and 1.0 msec.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 3, pp. 341–345, May–June, 2007. 相似文献
15.
V. V. Sapunov 《Journal of Applied Spectroscopy》2000,67(1):22-28
It has been established that the absorption and fluorescence spectra of octaethylporphin (OEP), mesotetraphenylporphin (TPhP),
and its complex with zinc (Zn-TPhP) in glycerol doped with dimethylformamide (DMF) or ethanol differ from the analogous spectra
of these compounds in ethanol or DMF, which is due to the formation of associates of porphyrin molecules in solutions of OEP,
TPhP, and An-TPhP with glycerol. For TPhP and Zn-TPhP, these differences are small, the maxima of the bands are shifted toward
longer wavelengths by 3–5 nm, and their halfwidths are increased by ∼ 16%; for OEP these changes are more significant. It
is shown that the duration of fluorescence of associates is much shorter than that of monomers. The probable mechanisms of
quenching of the fluorescence of dimers (oligomers) of molecules were considered. It has been suggested that one of the reasons
for the increased rates of deactivation of the excited states of dimers (oligomers) may be the decreased energy interval between
the excited and ground states of associates as compared with that of monomers.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 21–25, January–February, 2000. 相似文献
16.
Formations of triplet state, molecular cation radical, and phenoxyl radical of 3,4‐methylenedioxy phenol (sesamol, SOH) in organic solvents have been investigated by laser photolysis as well as pulse radiolysis techniques. Photolysis of SOH in cyclohexane has been found to produce both triplet state (λmax ~ 480 nm) and phenoxyl radical (425–430 nm) of SOH by mono‐photonic processes. However, radical cation (λmax = 450 nm) and phenoxyl radical of SOH have been observed on radiolysis in cyclohexane. Further, radiolysis of SOH in benzene has been found to produce phenoxyl radical only. Mechanism of phenoxyl radical formation by photo‐excitation of SOH has been studied and triplet energy level of SOH is estimated to lie between 1.85 and 2.64 eV. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
17.
We theoretically examine injection polarization of nuclear spins in silicon nanostructures with hyperfine interaction of nuclei
with excited triplet states. We predict the possibility of the appearance of self-sustaining nuclear spin polarization, initiated
by an external field. We show that if the external magnetic field is varied, we observe up to a 600-fold jump in the number
of spin-polarized nuclei. A similar up to 40-fold jump also appears as the charge carrier injection rate increases.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 5, pp. 647–653, September–October, 2006. 相似文献
18.
Iron disulfide reactivity relative to the components of composite polymer electrolytes based on chlorinated polyvinylchloride has been studied by taking differential infrared (IR) spectra. It has been shown that iron-containing admixtures on iron disulfide surface can initiate the decomposition processes of polymer systems. Possibility of diffusion to the volume of liquid electrolyte of surface iron—comprising compounds of different composition—has been shown. In the presence of lithium salts, these admixtures initiate the destruction processes of plasticizing additives and polymer matrix. The disclosed effects of interaction enable optimization of polymer electrolyte composition for the further use in the power source of Li–FeS2 system and to develop a complex of procedures connected with the preliminary treatment (thermal or chemical) of pyrite aimed at the modification of its surface properties. 相似文献
19.
We report on the spectroscopy of isolated chains of P3OT, in a highly dilute solution in the inert polymer host poly(methyl–methacrylate)
(PMMA). This environment permits a detailed analysis of emission transitions in the 1.9–2.2 eV range by suppressing the formation
of the lowest emitting-energy aggregated form of P3OT. Herein it is observed that the 1.9–2.2 eV band is in fact split into
low (red) and high (blue) energy forms in a highly analogous situation to that found for the conjugated polymer MEH-PPV. Another
focus of this work is an investigation of the interaction of singlet and triplet excitons in P3OT. The results indicate that,
like in MEH-PPV, triplet excitons are highly efficient fluorescence quenchers for P3OT, strongly quenching the fluorescence
of P3OT under even relatively low excitation intensities. 相似文献
20.
Oxygen quenching of excited triplet and singlet states of gas-phase anthracene and its derivatives that have similar energies
of the lower triplet levels but widely different oxidation potentials (0.44 < Eox < 1.89 V) was studied. Quenching rate constants for singlet (kSO2) and triplet (kTO2) states in addition to the fraction of oxygen-quenched singlet and triplet states qS
1(T1O2 were determined from the decay rates, fluorescence intensities, and delayed fluorescence as functions of oxygen pressure.
It was found that kSO2 values vary from 2·104 (9,10-dicyanoanthracene) to 1.2·107 sec−1·torr−1 (anthracene, 9-methylanthracene, 2-aminoanthracene) and kSO2 values from 5·102 to 1·105 sec−1·torr−1. The kSO2 values for anthracene, 9-methylanthracene, and 2-aminoanthracene, which have fast rates of interconversion from S1 to T1, are close to the rate constants for gas-kinetic collisions and are independent of the oxidation potentials (Eox). The quenching rate constants kSO2 for the other anthracene derivatives and kTO2 for all studied compounds decrease with increasing free energy of electron transfer ΔGET, which indicates the important role of charge-transfer interactions in the oxygen quenching of singlet S1- and triplet T1 states.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 1, pp. 36–42, January–February, 2008. 相似文献