Физика/7. Оптика
Tussupbekova A.K., Amochayeva G.P, Alpyssova G.K., Zhanasbayeva A.S., Kipshakov M.S.
Karaganda
state university named after academician Ye.A.Buketov,
Kazakhstan
The study of the kinetics of phosphorescence of
molecules of organic phosphors
Recently formed the real directions
of research the possibility of creating optical systems and components at the
molecular level, to fully meet the demands of modern technology. Examples of
such devices are optical measuring transducers, digital and analog optical
processors, optical logical elements of digital electronics, optical switching
devices, etc. As the element base for creation of such devices can be used
large organic molecules or a relatively small ensembles, and the management and
transmission of information carried by optical effects and optical
communication. This is reinforced by the analysis of the specific properties of
such molecules, in particular, a significant number of stable States of
molecular systems, the comparative ease of construction of the distributed
functional elements [1].
The object of the research is to
study the characteristics of the kinetics of xanthenes dyes was phosphorescence
of eosin and erythrosine with two-stage excitation. This was experimentally
investigated kinetics of phosphorescence arising from the use as second stage
of two-stage excitation of a quantum generator in the absorption band Т1→Т2..
In work it was studied the kinetic
curve of the intensity of delayed fluorescence (to IMF) erythrosine in an alcohol
solution at a constant pumping energy and concentration of dye molecules in T1
state 10-3 mol/l. From the presented data it follows that for
erythrosine as eosin, the largest deviation from the exponential dependence
observed in the initial parts of the attenuation to IMF. In the far temporal
stages of kinetic processes time dependence to IMF is linear. A similar kinetic
curve may be due to participation in the energy conversion T1-excitations of
competing linear and non-linear relative to [T1] processes:
education (T1...S0) complexes and triple-triplet
annihilation associated with the formation of (T1...T1)
complexes.
It is known that in the absorption
spectra of the dyes in the formation of associates appear as short-wave and
long-wave maxima, which is related to the mutual orientation of molecules in
the associate. Spectra of fluorescence
always undergo a long-wave shift.
In Fig. 1 shows emission spectra of
the eosin as a comparison of the spectra for the presence of associated species
in solutions (1 – C=10-4 mol/l; 2 – C=10-3 mol/l). It is
known that associates colors begin to appear in water and alcohol solutions of
dyes of high concentrations [2].
Fig. 1. Emission spectra of eosin at different concentrations
In charts 1-2 shows emission spectra of eosin in alcohol solution at
concentrations of 10-4-10-3 mol/l. As can
be seen from Fig. 1, with increasing concentration there is a shift of the
spectrum in long-wave region. When comparing the highs of 1-2 it can be
concluded that at concentrations of dyes embedded in polymer films not
exceeding 10-4 mol/l, there is only a monomer, i.e. by the formation
of associates can be neglected. Thus, it is revealed that under the influence
of two-stage excitation in the kinetic curve of the phosphorescence occurs a
failure associated with the devastation of molecules in T1-condition.
References
1. Minaev B.F., Murugan
N.A., H. Agren H. Dioxygen spectra
and bioactivation/ B.F. Minaev,
N.A. Murugan, H. H. Agren
// Int. J. Quant. Chem. – 2013. – V.113. – P.1847–1867.
2. Черных С. В.,
Овчинников О. В., Воробьева Р. П., Латышев А. Н., Алпатова Д. В., Утехин А. Н.,
Евлев А. Б., Смирнов М. С. Исследование особенностей
ассоциации молекул метиленового голубого в растворах
по инфракрасным спектрам поглощения // ВЕСТНИК ВГУ, Серия: Физика. Математика.
- 2006, №1. – С. 97 – 101.