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0Spectral properties of substituted arylpolyenes and cross-conjugate ketones perspective for photonics applications
N.L. Naumova1*, I.A. Vasil'eva1, S.N. Gladenkova1, K.R. Karimullin1'2, O.N. Korotaev1,
A.V. Naumov1'2
1-Moscow Pedagogical State University (MPGU), Moscow, Russia 2- P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Troitsk Branch, Moscow, Troitsk, Russia
* n_l_naumova@mail.ru; www.mpgu.su
Important information about interaction of electronic and vibronic excitations in complex organic molecules can be obtained from optical spectroscopy of doped solids at low temperatures. Luminescence and absorption spectra of dye molecules in solid matrices consist of the vibronic bands which correspond to the transitions of molecules to different vibronic levels.
Here we investigate the optical spectra for two classes of molecules perspective for various photonics and optoelectronics applications: substituted arylpolyenes and cross-conjugate ketones.
The fluorescence and fluorescence excitation spectra of some substituted arylpolyenes in solid Shpol'skii matrices have been studied at a temperature of 4.2 K. The spectra exhibit a weakly pronounced vibrational structure. We have developed a method for determination of parameters responsible for the shape of spectra. The method is based on the modeling of the spectra by series of vibronic bands, each of which consists of a narrow zero-phonon line and a broad phonon sideband. This makes it possible to calculate the conjugated optical spectra with the weakly pronounced vibrational structure and compare them with the measured spectra. The deviations from the mirror symmetry between the measured fluorescence and fluorescence excitation conjugate spectra are explained by the combined effect of the Franck-Condon and Herzberg-Teller interactions.
The spectra of luminescence and absorption (fluorescence excitation) of some cross-conjugate ketones were studied at cryogenic temperatures. We found anomalies in the fluorescence and fluorescence-excitation spectra of some of the studied compounds: a pronounced upset of mirror symmetry of the spectra and a large Stokes shift. The experimental spectra and the spectra calculated theoretically using the theory of two-well adiabatic potentials were subjected to a comparative analysis.
A comparative analysis is performed of the parameters of the Franck-Condon and Herzberg-Teller interactions that determine the shape of the conjugated optical spectra of n-conjugated molecules having the same sets of structural molecular elements. The possibility of applying a fragmentary approach to analyzing the spectra of these molecules is demonstrated.
This presentation has been supported within the state assignment of the Ministry of Education of the Russian Federation "Physics of nanostructured materials and highly sensitive sensorics: synthesis, fundamental research and applications in photonics, life sciences, quantum and nanotechnology" (MPGU, theme No. - 124031100005-5).
[1] N.L. Naumova, et al, Evaluation of parameters of intramolecular interaction from absorption and fluorescence spectra of substituted arylpolyene with poor resolved vibrational structure, Journal of Luminescence 111, 37-45 (2005).
[2] N.L. Naumova, et al, Study of vibronic interactions in impurity centers by conjugate fluorescence and absorption spectra with a poorly resolved vibrational structure, Optics and Spectroscopy 98, 535-542 (2005).
[3] N.L. Naumova, et al, Fluorescence Spectra of Some Cross-Conjugate Ketones: Experiment and Calculations Based on the Model of Two-Well Adiabatic Potentials, Optics and Spectroscopy, 92, 383-388 (2002).
[4] V.V. Kompaneets, K.R. Karimullin, I.A. Vasilieva, A.V. Naumov, Effect of Identical Sets of Structural Elements of n-Conjugated Molecules on the Parameters of Intra- and Intermolecular Interaction, Bulletin of the Russian Academy of Sciences: Physics 84, 272-280 (2020).
