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1.
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
2.
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
3.
Spectral-luminescent properties and photoinduced transformations of bisanthene and bisanthenequinone
Based on the study of photochemical transformations of bisanthene in oxygen-containing solutions, it was established that
the final product of this reaction is bisanthenequinone. It is shown that in the course of this oxidation reaction the intermediate
compounds endomonoperoxide and bisanthene endobiperoxide are formed. Quantum-chemical calculation of the geometrical structure
and electronic spectra of the endoperoxides has shown that they have a nonplanar structure, and their absorption spectra experience
a large hypsochromic shift. The absorption and fluorescence spectra of solutions of bisanthene in different solvents at 300
and 77 K were investigated. The large Stokes shift of the fluorescence spectra of the solutions of bisanthene in benzene and
in its methyl derivatives is explained by the action of intermolecular interactions. The quasi-line fluorescence spectra of
solutions of bisanthene in the matrices of saturated hydrocarbons were recorded.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 2, pp. 176–182, March–April, 2000. 相似文献
4.
We have obtained and analyzed the absorption, fluorescence, and fluorescence excitation spectra of indole vapor, N-acetyl-L-tryptophan
vapor, and 3-indole aldehyde vapor. From analysis of the dependence of the fluorescence spectrum of the free indole molecules
on the wavelength of the exciting radiation λex, it follows that emission of fluorescence occurs when the molecules undergo a transition from the one electronically excited
state 1Lb. The fluorescence spectra of the studied compounds are insignificantly different, suggesting a major role for the indole
chromophore in formation of the compounds. The absorption spectrum of N-acetyl-L-tryptophan, in which the group of atoms is
added to the indole ring through a-C-C bond, is similar to the spectrum of indole, while the spectrum of 3-indole aldehyde
is significantly different from the indole spectrum due to the effect of the C=O group conjugated with the indole ring. The
fluorescence excitation spectra are considerably different from the absorption spectra. This is associated with the strong
dependence of the quantum yield for the free molecules on λex. Qualitatively, they are mirror-symmetric to the fluorescence spectra of the stodied compounds. Analysis of the data obtained
provides a basis for assuming that in the case of free molecules of indole and its derivatives, the 1La absorption in the extreme long-wavelength region of the spectrum does not overlap 1Lb absorption.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 218–222, March–April, 2007. 相似文献
5.
The spectroscopic characteristics of hybrid organic-inorganic films and solutions of ethoxysilicon-containing amidophosphate ligands in acetonitrile have been investigated. Inhomogeneous broadening of the absorption and fluorescence spectra which is characterized by the spectral dependence of the fluorescence and fluorescence excitation bands on the excitation and registration wavelength, respectively, is associated with the presence of a set of -(Si-O)n- siloxane structures with various terminal fragments in both the films and solutions. The established general spectral rules are discussed with allowance for the characteristic features of the electronic structure of silicon-organic compounds containing an oxygen atom the unshared electron pair of which ensures the delocalization of the electron density over the siloxane chain.Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 71, No. 6, pp. 788–792, November–December, 2004.This revised version was published online in April 2005 with a corrected cover date. 相似文献
6.
G. G. D'yachenko V. A. Petukhov S. M. Arabei T. A. Pavich 《Journal of Applied Spectroscopy》2003,70(2):208-215
At 4.2 K, the quasiline fluorescence and fluorescence-excitation spectra (in the region of the S
1 S
0- and S
2 S
0 transitions) of bisanthene in n-hexane have been obtained. Using the MO/M8ST method, the calculation of the A
g
normal modes in the S
0, S
1, and S
2 electronic states was carried out for the bisanthene molecule; the relative intensities of the transitions in the corresponding vibronic spectra were also calculated. The analysis of the results of calculations and experiment made it possible to draw conclusions on the form of the modes for a number of normal vibrations which are active in the bisanthene vibronic spectra. 相似文献
7.
A normal coordinate analysis on chlorambucil and thioguanine has been carried out with a set of symmetry coordinates following
Wilson’s F-G matrix method. The potential constants evaluated for these molecules are found to be in good agreement with literature values
thereby confirming the vibrational assignments. To check whether the chosen set of vibrational frequencies contribute maximum
to the potential energy associated with the normal coordinates of the molecule, the potential energy distribution has been
evaluated.
相似文献
8.
Kh. Sh. Abdulov 《Journal of Applied Spectroscopy》2007,74(2):188-193
A method is proposed for assigning absorption bands in IR spectra of polyatomic molecules. An algorithm is developed and a
Fortran program is written based on this method. The method is illustrated for the example of the toluene molecule.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 169–173, March–April, 2007. 相似文献
9.
S. F. Shkirman L. L. Gladkov V. K. Konstantinova K. N. Solov’ev 《Journal of Applied Spectroscopy》1999,66(3):400-409
Quasi-line fluorescence and fluorescence-excitation spectra of tetrabenzoporphin (H2TBP) and its deuterated derivative (D2TBP) in n-octane at 77 K were measured and analyzed. A calculation of normal vibrations of the H2TBP and D2TBP molecules has been performed. The normal vibrations of these molecules were calculated with the use of the valence force
fields of porphin and phenanthrene (the direct spectral problem was solved). Good agreement between the calculated and measured
frequencies of the investigated normal vibrations has been obtained without correction of the transfered force constants.
A detailed interpretation of the fluorescence spectra obtained is presented. It is shown that on deuteration of H2TBP, the behavior of the quasi-lines in the fluorescence-excitation spectra in the region of resonance with the S2←S0 transition becomes more complex.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 375–382, May–June, 1999. 相似文献
10.
An analytical expression of the emission and absorption spectra for a Λ type three-level cavity-bound atom interacting with
a two-mode cavity field is given using the dressed states of the system. We take into account explicitly the nonlinearities
of both the field and the intensity-dependent atom-field coupling. The characteristics of the emission and absorption spectra
when one of the two-mode cavity fields is in a binomial state and the other is in a squeezed coherent state are exhibited.
The effects of the mean number of photons, detuning, and the kinds of nonlinearities on the spectra are analyzed. 相似文献
11.
提出探测复杂力学振动系统耦合振动模式的方法:通过测量力学振动系统中某一易于探测的振动模式对外力的响应行为,在该振动模式应变落后于应力的相位差-频率谱(表观机械能耗散-频率谱)中,除了能观察到与被测量振动模式本征频率所对应的相位变化外,与被测量振动模式耦合的其他振动模式也表现为共振吸收峰;从共振吸收峰的性质,如峰位、峰宽、峰高等可以得到相应耦合振动模式的本征频率、损耗以及耦合强度等信息.以倒扭摆力学系统为例,通过测量扭摆的扭转振动模式应变落后于应力的相位差-频率谱研究了扭摆系统中摆杆的进动振动模式. 相似文献
12.
L. L. Gladkov S. F. Shkirman V. K. Konstantinova K. N. Solov'ev 《Journal of Applied Spectroscopy》2000,67(5):755-762
Quasiline fluorescence and fluorescence-excitation spectra of tetraazaporphin and its N-deuterated derivative in n-octane at 77 K have been investigated, and the frequencies of normal vibrations in electronic states S
0 and S
1 have been determined. Calculation of normal vibrations of these molecules has been done and, on its basis, the experimental data are interpreted. It is shown that in the spectra, predominantly the totally symmetric vibrations of type A
g
symmetry of the point D
2h
symmetry group are active. Some activation of the nontotally symmetric B
1g
vibrations in the fluorescence-excitation spectra is explained by the nonadiabatic interaction of the vibrational sublevels of the excited electronic state S
1 with the purely electronic level S
2. 相似文献
13.
14.
L. L. Gladkov S. F. Shkirman V. K. Konstantinova E. A. Makarova K. N. Solov'ev 《Journal of Applied Spectroscopy》2002,69(6):811-816
Quasiline fluorescence and fluorescence-excitation spectra of tetraazachlorin and its N-deuterated derivative in n-octane at 77 K have been investigated and the frequencies of the normal vibrations for the electronic states S
0 and S
1 have been determined. Calculation of the normal vibrations of these molecules has been done and used to interpret the experimental data. Based on the results of analysis of the intensities in the spectra, the change in the structure of the molecule in the electronic state S
1 is discussed. 相似文献
15.
16.
利用PE-Lambda900分光光度计,测量了非线性晶体的散射及吸收光谱,实验中避免了大块双轴晶体镜面反射作用引起的测量误差.实验结果表明,随光子能量增加,晶体材料的光吸收在400nm以外波段显著增加。对散射谱进行分析,来源于晶体结构内部的缺陷。如位错、包裹体的尺寸主要分布在lOOnm以上,这些缺陷在短波段的光散射作用有上升的趋势。 相似文献
17.
We investigate the energy structure of colloidal CdS nanocrystals by measuring the UV–vis absorption spectra. Nanocrystals were synthesized by sol–gel method in a gelatin matrix in the size range from 2.5 to 3.9 (±0.2) nm. In order to interpret the UV–vis absorption spectra we calculate the energy spectrum of electron quasi-stationary states using the model of open nanocrystal as well as the hole stationary spectrum in a two-band approach. It is shown that the main contribution to the absorption spectrum is made by interband transitions 1S3/2→1Se and 1P3/2→1Pe, and its shape is determined by the size distribution of nanoparticles. For this system the estimated values of the effective masses of the heavy hole and light hole are 1.44m0 and 0.28m0, respectively. 相似文献
18.
19.
采用在惰性气体中蒸发的方法获得了沉积在ZnS基片上的InSb纳米晶体,其平均尺寸随惰性气体的压强增加而增大.从实验测量的室温吸收谱上看到,当纳米晶体的平均直径从27.9 nm减小到24.2nm再到21.4 nm时,其吸收边分别向高能方向移动了0.0151 eV和0.0145 eV.用有效质量近似模型计算了半导体纳米晶体的吸收边相对其体材料的移动,将理论计算与实验结果进行了比较. 相似文献
20.
N. A. Borisevich T. F. Raichyonok A. A. Sukhodola G. B. Tolstorozhev V. A. Shashilov 《Journal of Applied Spectroscopy》2005,72(1):49-58
Extensive studies of the spectral-luminescent characteristics of four 8-azasteroids and a model compound 2-(3,3-dimethyl-1,2,3,4-tetrahydro-1-isoquinolidene)-5,5-dimethyl-1,3-cyclohexanedion in the gas phase have been made. From the analysis of the dependences of the absorption spectra on the vapor pressure (Tlow) and the fluorescence spectra on Tlow and the exciting radiation wavelength (exc) a conclusion on the presence in the vapors of the investigated 8-azasteroids of three absorption and fluorescence centers (S-, M-, and L-centers) has been drawn. The absorption spectra of these centers strongly overlap. Their long-wave absorption boundaries have been determined. The dependence of the fluorescence spectra of all three centers on exc, which is inherent in rarefied gases of individual organic molecules, is observed. The S-centers are the molecules of the initial steroids, and the M- and L-centers are the molecules of thermo- and phototransformations of the initial steroids. The model compound in the gas phase is characterized by the same dependences of the fluorescence spectra on Tlow and exc as those inherent in 8-azasteroids. Taking into account the additional data obtained as a result of investigation of the absorption and fluorescence spectra of solutions of the substances extracted from vacuum cells after the investigation of 8-azasteroids and the model compound in the gas phase, conclusions on the nature of the M- and L-centers have been drawn.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 1, pp. 48–57, January–February, 2005. 相似文献