1238
IBRAYEV et al.
The absorption and fluorescence spectra of dye II
in ethanol (Fig. 2b, curves and ') with maxima at
REFERENCES
1
1
1. A. A. Eliseev and A. V. Lukashin, Functional Nanomaꢀ
terials, Ed. by Yu. D. Tret’yakov (Fizmatlit, Moscow,
2010) [in Russian].
2. A. G. Vitukhnovsky, M. I. Sluch, J. G. Warren, and
M. C. Petty, Chem. Phys. Lett. 173, 425 (1990).
3. A. K. Dutta, T. N. Misra, and A. J. Pal, Langmuir 12
abs
λmax
fl
= 550 nm and
= 573 nm exhibit a vibronic
λmax
structure. The quantum yield of fluorescence meaꢀ
sured relative to our standard of rhodamine C (ϕfl
=
0.70) was 0.75.
,
The absorption spectra of dye II in LB films
(Fig. 2b, curves ) are also broad bands with two
359 (1996).
2–4
4. S. Acharya, D. Bhattachrjee, and G. B. Talapatra,
J. Colloid Interface Sci. 244, 313 (2001).
5. G. A. Biesmans, G. Versbeek, B. Verschuere, et al.,
Thin Solid Films 169, 127 (1989).
6. F. Embs, D. Funhoff, A. Laschewsky, et al., Adv. Mater.
maxima at 522 and 560 nm, shifted toward the longꢀ
wave side relative to the absorption spectrum of dye in
ethanol solution. The halfꢀbreadth and optical density
of the absorption bands increase as the concentration
of dye in the film rises.
3, 25 (1991).
Substantial changes were observed in fluorescence
7. A. Laschewsky, Eur. Chem. Chronicle
8. V. V. Arslanov, Russ. Chem. Rev. 60, 584 (1991).
9. V. I. Zemskii, Yu. L. Kolesnikov, and I. K. Meshkovskii,
Physics and Technology of Pulsed Dye Lasers (SPbGU
ITMO, St. Petersburg, 2005) [in Russian].
10. F. Bayrakceken, A. Yaman, and M. Hayvali, Spectroꢀ
chim. Acta 61, 983 (2005).
11. M. Ahmad, T. A. King, D.ꢀK. Ko, et al., Opt. Laser
Tech. 34, 445 (2002).
12. R. Schiener, H. Pillekamp, M. Kerscher, and
R. U. Peter, MMW Fortschr. Med. 145 (8), 45 (2003).
13. R. Giri, Spectrochim. Acta A 60, 757 (2004).
2, 13 (1997).
spectra (Fig. 2b, curves
absorption spectra of LB films on concentration was
similar for dyes and II. The most intense fluoresꢀ
cence is displayed by films with dye concentrations of
2'–4') if the dependence of the
I
C
d = 10 mol % (Fig. 2b, curve
2
fl
λmax
'
). The spectrum with
a maximum at wavelength
= 583 nm is close in
shape to that of the ethanol–dye solution. The band
fl
Δλ1/2
fl
halfꢀbreadth is
= 94 nm, while it is
=
Δλ1/2
51 nm for the ethanol solution. Fluorescence quenchꢀ
ing and a longwave shift of the band occurs as the conꢀ
centration of dye rises (curves 3' and 4'). The mirror
symmetry of the absorption and fluorescence spectra
is broken at dye concentrations of 33 and 50 mol %.
The reason for such behavior of the fluorescence
spectra could be dye molecule aggregation. Molecular
aggregation is, however, first manifested in electronic
absorption spectra as a rule [23]. As is evident from
Fig. 2b, the apparent correlation between the absorpꢀ
tion and fluorescence spectra disappears at high dye
concentrations. Analysis of the absorption spectra
allow us to argue for the presence of dye II aggregates
14. V. I. Alekseeva, O. L. Kaliya, E. A. Luk’yanets, et al.,
Patent RF No. 2095384.
15. F. Rullens, M. Divillers, and A. Laschevsky, Macromol.
Chem. Phys. 205, 1155 (2004).
16. S. A. Yeroshina, N. Kh. Ibrayev, S. E. Kudaibergenov,
et al., Thin Solid Films, No. 516, 2109 (2008).
17. V. V. Arslanov, Russ. Chem. Rev. 69, 883 (2000).
18. T. Clark, A Handbook of Computational Chemistry A
(Wiley, New York, 1985).
19. S. Acharya, T. Kamilya, J. Sarkar, et al., Mat. Chem.
in LB films to the same extent as for dye I.
Phys. 104, 88 (2007).
20. M. Kodama, O. Shibata, Sh. Nakamura, et al., Colꢀ
Under conditions of dense molecular packing in
LB layers, excimers can emerge out of dimeric states
and be detected from their characteristic longwave fluꢀ
orescence [22, 23]. We may assume that the red shift
observed in the fluorescence spectra of LB films of dye
II is associated with the formation of dye excimers.
loids Surf. B 33, 211 (2004).
21. A. N. Terenin, Photonics of Molecules of Dyes and
Related Organic Compounds (Nauka, Leningrad, 1967),
p. 616 [in Russian].
22. N. Kh. Ibraev, A. M. Zhunusbekov, and D. Zh. Satybalꢀ
dina, Opt. Spectrosc. 87, 298 (1999).
ACKNOWLEDGMENTS
23. V. I. Yuzhakov, Russ. Chem. Rev. 61, 613 (1992).
This work was supported by the Kazakhstan Minisꢀ
try of Education and Science, project no. 1196/GF.
Translated by E. Kapinus
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A
Vol. 87
No. 7 2013