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1.
V. N. Knyukshto E. I. Sagun A. M. Shul’ga S. M. Bachilo É. I. Zen’kevich 《Journal of Applied Spectroscopy》1998,65(4):487-491
For the first time it is discovered that the mono- and dimesoaryl substitution in porphyrins (free bases and their Zn-complexes)
as well as the formation of chemical dimers with a phenyl spacer are manifested in the abrupt reduction (300–500 times less)
of the lifetime of T1-states at 295 K and are not accompanied by enhancement of the nonradiative deactivation of the S1-state. These effects are associated with the nonlinear dynamic deformations of the π-conjugate macrocycle in the T1-state due to torsional oscillations of a phenyl ring about a single C–C-bond in sterically complicated porphyrins.
To whom correspondece should be addressed.
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. 4, pp. 471–475, July–August, 1998. 相似文献
2.
Quasiline fluoresence and fluorescence excitation spectra of NH-isomers of 2,2,7,7,12,13,17,18-octamethylisobacteriochlorin
(cis- and trans-) in polycrystalline matrices in n-hexane and n-octane at 4.2 K are obtained. A vibration analysis of the
spectra in combination with the data of quasiline spectra of cyano-substituted octaethylisobacteriochlorin and octamethylporphin
permitted a qualitative interpretation of the vibronic spectra of NH-isomers. It is inferred that for a trans-isomer, the
0–0 transition S2⇃S0 is localized in the region of electron-vibrational S1⇃S0 transitions; the interval S2-S1 has a magnitude of about 1300 cm−1.
Reported at the VIIIth International Conference on the Spectroscopy and Chemsitry of Poprhyrins and Their Analogs, Belarus,
Minsk, September 22–26, 1998.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 79–85, January–February, 2000. 相似文献
3.
S. M. Arabei 《Journal of Applied Spectroscopy》1998,65(4):560-566
Monochromatic photoexcitation and selective registration in bands of purely electronic S1↔S0 transitions resulted in fine fluorescence and absorption (fluorescence excitation) spectra of hypericin in polyvinylbutyral
at a temperature of 4.2 K. Vibration analysis of the spectra is done and conclusions are made about the form of many normal
vibrations. It is found that the formation of intramolecular hydrogen bonds in the hypericin structure has a substantial effect
on the relative position of the electronic vibrational levels of the pigment molecule.
Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus, 70, F. Skorina ave., Minsk 200072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 4, pp. 539–545, July–August, 1998. 相似文献
4.
I. V. Filatov I. V. Avilov É. I. Zen'kevich A. M. Shul'ga 《Journal of Applied Spectroscopy》1999,66(4):593-596
On the basis of quantum-chemical calculations of the properties of excited states and comparison with the experimental data,
we show that at room temperature unliganded dimers of Zn-porphyrins and Zn-chlorins, bonded through a CH2−CH2-group, are in a conformation close to an eclipsed one, while their dipyridine complexes are in an unchanged conformation.
For triad and pentad complexes, formed as a result of extraliganding of dimers of Zn-porphyrins with di- and tetrapyridyl-substituted
free bases of porphyrins, the calculations predict the presence of states with transfer of a charge from dimers onto a free
porphyrin base that are manifested in the region between the Q- and B-transitions in electron absorption spectra.
To whom correspondence should be addressed.
Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 535–537, July–August, 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.
Using the method of phase-sensitive detection, we investigated the photoconductivity spectra of polycrystalline p-CuInSe2 films obtained in vacuum by the method of pulsed laser vaporization of initial single crystals. We show that, in contrast
to single crystals, films are characterized by monopolar photoconductivity in the extrinsic and intrinsic regions of optical
absorption and by a linear mechanism of recombination of nonequilibrium charge carriers at the intensities of illumination
0–100 mW/cm2 in the temperature range 80–300 K.
Institute of the Solid-State and Semiconductor Physics, National Academy of Sciences of Belarus, 17, P. Brovka St., Minsk
220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii. Vol. 66, No. 1, pp. 138–141, January–February, 1999. 相似文献
7.
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
8.
V. S. Pavlovich 《Journal of Applied Spectroscopy》1997,64(6):764-777
Polar luminescence probe+polar medium subsystems are considered. True minimization parameters of the free energy F are obtained.
It is shown that Franck-Condon transitions between F-terms of different electronic states are generally not “vertical”. A
complete thermodynamic classification of photoinduced processes of orientational relaxation in the excited S1 and ground S0 states is presented. Depending on the excitation conditions they can be either exo- or endothermic, spontaneous or induced
(not spontaneous), and accompanied by an increase or decrease in entropy. Indifferent processes also take place. Regularities
of shifts of fluorescence spectral bands and burned holes in time-resolved experiments are discussed.
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. 6, pp. 753–765, November–December, 1997. 相似文献
9.
I. V. Bodnar A. G. Karoza E. A. Kudritskaya A. G. Smirnova 《Journal of Applied Spectroscopy》1997,64(2):279-282
The IR reflection spectra of In2S3, CuIn5S8, AgIn5S8 compounds with a spinel structure are investigated. Using the DA-K-K method, we determined the frequencies of longitudinal
and transverse phonons, attenuation coefficients of phonons, and IR intensities, as well as the dielectric constants ε0 and ε∞.
Belarusian State University of Information Science and Radioelectronics, 6, P. Brovka St., Minsk 220600, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 2, pp. 263–265, March–April, 1997. 相似文献
10.
By taking as an example a He−Ne laser that operates at the 3S2−3P4 transition (λ=3.39 μm), we studied the specific features of nonlinear interaction of the waves of linear orthogonal polarizations
in a transverse magnetic field. Using mutually orthogonal transverse magnetic fields on the neighboring portions of an active
medium, we implemented a regime of two-frequency generation, which was investigated theoretically and experimentally.
To whom correspondence should be addressed.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 568–573, July–August, 1999. 相似文献
11.
A. P. Losev S. M. Bachilo D. I. Volkovich Yu. S. Avlasevich K. N. Solov’yov 《Journal of Applied Spectroscopy》1997,64(1):62-71
Photoinduced electron transfer (PET) in a Pd-porphyrin-quinone complex (Pd-P-Q) was investigated using the flash photolysis
method in microsecond and picosecond range and by luminescence. The investigations were performed for toluene solutions. Intramolecular
PETs in the lower excited singlet state (kCT=1.7·1010 sec−1) and in the triplet state (kCT=2.5·108sec−1) were observed. For a quantum yield of the triplet state that is close to 1 in Pd-porphyrin (Pd-P) this yield is equal to
0.4 in Pd-P-Q. This decrease is the result of PET in the excited state and, possibly, in an unrelaxed triplet state. Triplet
Pd-P-Q molecules were efficiently quenched by unexcited molecules, and this process is related to intermolecular charge transfer.
This electron transfer is likely to occur from the Pd-P protion of an excited molecule to the quinone protion of an unexcited
molecule in the collisional complex (Pd-P-Q)2. Charged radicals, formed once the collisional complex is transferred and separated, have a wide absorption band with a maximum
of about 960 nm. The average lifetime of the radicals was about 2 msec.
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. 61–70, January–February, 1997. 相似文献
12.
The methods of selective laser spectroscopy applied at 1.8–10 K to a glass-forming tetrahydrofuran-toluene (3∶1) mixture have
revealed that in the dimers of tetrapyrrole compounds (ethane-bis-octaethylporphyrins, ethane-bis-Zn-octaethylchlorins, heterodimers
of Zn-cyclopentane porphyrins) the exciton interactions (V12≈118 cm−1) and S-S-transfer of energy (of probability F≈11 sec−1) are implemented under conditions of substantial inhomogeneous broadening (δF1/2≈50 cm−1). Upon excitation of a donor component in the dimers, one observes a strong quenching of its emission, the disappearance
of the fine structure in the fluorescence spectra, a decrease in the efficiency of spectral hole burning by, approximately,
an order of magnitude, and a 12-fold increase in their halfwidth.
To whom correspondence should be addressed.
Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 500–504, July–August, 1999. 相似文献
13.
V. N. Knyukshto A. M. Shul’ga E. I. Sagun É. I. Zen’kevich 《Journal of Applied Spectroscopy》1998,65(6):943-951
It is established experimentally for the first time that Zn-octaethylporphyrin in a solution of dried methyl cyclohexane is
in unliganded form in the temperature interval of 293-77 K. This form is characterized by the shortest-wave position of absorption
and luminescence spectra, the independence of the degrees of fluorescence and phosphorescence polarizations from the excitation
wavelength, and high phosphorescence time (τT=126 μsec) and quantum yield (φp=0.085) at 77 K. Adding electrodonor components to the methyl cyclohexane or going over to
alcohol-containing polar media leads to the formation of a monoliganded form of ZnOEP, for which we observe a bathochromic
shift of ≈150–350 cm−1 for Q(0,0) absorption and luminescence bands, a splitting of ≈50–100 cm−2 for the Q(0, 0) absorption band, and phosphorescence quenching (τT=60 μsec, φp=0.05-0.03 at 77 K). The effects revealed are explained by a decrease in the symmetry of a ZnOEP molecule in extra
liganding and by an increase in the probability of nonradiative activation for a T1-state due to the extra ligand being involved in the exchange of electron-excitation energy and to the enhancement of a spin-orbital
coupling as a result of the disturbance of the planarity, of a macrocycle.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 900–907, November–December, 1998. 相似文献
14.
G. G. Fedoruk 《Journal of Applied Spectroscopy》1998,65(3):420-426
Attenuation of the signals of the nutation echo of E’-centers in crystalline and glass quartz was experimentally investigated
at room temperature. The nutation echo in EPR was excited in the single-photon regime and formed by two Zeeman-field pulses
with duration t1 and t2 (t1<t2) and time interval between them τ. The echo signal was recorded during the second pulse at t≈2t1+τ. It was established that this signal attenuation, measured as t1 increased, follows an, exponential law, its rate Γ is much less than 1/T2 (T2 is the transverse relaxation time), and it linearly increases with an increase in the amplitude of the exciting SHF field
B1. The parameters of the dependence of Γ on B1 correlate with the parameters of the analogous dependence revealed previously for attenuation of nutation of E’-centers in
quartz in the two-photon regime at T=4.2 K. At the same time, the value of Γ measured with different values of τ is independent
of B1 and is equal to 1/T1, where T1 is the longitudinal relaxation time.
A. N. Sevchenko Scientific Research Institute of Applied Physical Problems, 7, Kurchatov St., Minsk, 220064, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 3, pp. 405–411, May–June, 1998. 相似文献
15.
G. A. Zalesskaya 《Journal of Applied Spectroscopy》1998,65(5):701-721
Results of investigations of the process of multiphoton excitation of polyatomic molecules by CO2-laser radiation are presented. The mechanism of formation of the profiles of IR absorption bands of polyatomic molecules
is discussed. New experimental methods of investigation of relaxation processes at high levels of vibrational excitation of
molecules in the ground and triplet states are considered. For vapors of polyatomic molecules and their mixtures with foreign
gases, the quantitative characteristics of the collisional exchange and the vibrational-energy transfer as well as the rates
of intercombinational conversion ⇛ and triplet-triplet transfer are presented and their dependences on the vibrational-excitation
level are discussed.
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. 5, pp. 675–693, September–October, 1998. 相似文献
16.
A procedure for producing 9,10-diiodoanthracene that is an alternative to the known procedure is described. The spectra of
absorption and fluorescence in hexane, carbon tetrachloride, and polymethylmethacrylate are measured at 22°C. The quantum
yield of undegassed liquid solutions in hexane and carbon tetrachloride in excitation at the maximum of the 0←0 band is practically
the same and is equal to 0.018. In excitation in shorter-wave vibrational bands, it is different for different solvents and
decreases noticeably as the frequency of the exciting light increases. The decrease in the yields is explained by the existence
of a fast nonradiative process from hot (Franck-Condon) vibrational S1-states capable of competing with vibrational relaxation. A possible scenario of this approach is discussed.
Institute of Molecular Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 2, pp. 197–200, March–April, 1999. 相似文献
17.
The state of Pd in Pd/TiO2 and Pd/TiO2(Nb2O) systems is investigated by means of electron diffuse reflection spectroscopy, x-ray electron spectroscopy, and IR spectroscopy
of adsorbed CO as a function of thermal and reduction treatments. Modification of titanium dioxide TiO2 leads to intensification of metal-support interaction, which manifests itself as an increase in the content of surface complexes
of Pd strongly bound to TiO2. As a result of electron density transfer from TiO2 with electron-excess Ti3+ ions to the metal deposited, the latter acquires an enhanced reduction ability.
Institute of Physical and Organic Chemistry, National Academy of Sciences of Belarus, 13, Surganov St., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 1, pp. 84–88 January–February, 1999. 相似文献
18.
G. A. Zalessakaya D. L. Yakovlev D. I. Baranovskii E. G. Sambor 《Journal of Applied Spectroscopy》1998,65(3):351-356
Collisional losses of vibrational energy in mixtures of benzophenone excited by nitrogen laser radiation (λ=337 nm) and foreign
gases (Ar, Kr, SF6, C5H12) were studied by time-resolved delayed luminescence. It is established that the intensities and rates of decay of the fast
and slow components of delayed luminescence can be used to evaluate the characteristics of V–V– and V–T–transfer of vibrational
energy. For the V-V-process, the efficiencies and mean energies transferred in a collision are determined. It is shown that
in the mixture with multiatomic gases, vibrational equilibrium is reached after a few collisions, the number of which decreases
as the molecule of the foreign gas becomes more complicated. The V–V–process is characterized by high efficiencies of collisions
typical for “supercollisions”. The experimental characteristics of V-V-transfer correlate well with ergodic transfer of vibrational
energy predicted by statistical theories. 0120 0126 V 3
Institute of Molecular and Atomic Physics of the National Academy of Science of Belarus, 70, F. Skorina Ave., Minsk, 220072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 3, pp. 340–345, May–June, 1998. 相似文献
19.
Based on the measured spectra of the action of the process of cis-trans-NH(ND)-isomerization of 5-cyano-2,2,8,8,12,13,17,
18-octamethylisobacteriochlorin (H2-COMiBCh) and its deuteroderivative (D2-COMiBCh) in polycrystalline matrices of n-octane and r hexale at 4.2 K, it is established that the character of embedding
of COMiBCh in the matrices of n-alkanes has a substantial effect on the barrier of dark rearrangement and the rate of photoinduced
NH(ND)-rearrangement, while deuteration of the center of a molecule shifts the dynamic equilibrium toward a trans-form in
photoexcitation.
To whom correspondence should be addressed.
Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina, Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 555–559, July–August, 1999 相似文献
20.
V. I. Arkhipenko S. M. Zgirovskii L. V. Simonchik 《Journal of Applied Spectroscopy》1999,66(3):386-393
The dimensions of the region of the cathode drop in potential in a helium glow discharge at atmospheric pressure (in Kiselevskii’s
plasma source) are determined. Using Stark spectroscopy of the Balmer-series hydrogen line Hβ the spatial distribution of the constant and variable components of the electric-field strength is measured.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 362–368, May–June, 1999. 相似文献