Characterization of acetylacetonato-bis-(2-(4-amino-2-hydroxyphenyl) benzthiazole) complex

Article abstract of DOI:10.1080/15421400802615402

Organic luminescent materials have received great attentions due to their potential application subjects onto full color image displays such as mobile phones, PDA and etc. In the present work, we synthesized new electroluminescence material such as acetyl

Full text of DOI:10.1080/15421400802615402

This article was downloaded by: [Gebze Yuksek Teknoloji Enstitïsu ]
On: 20 December 2014, At: 12:50
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954
Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH,
UK
Molecular Crystals and Liquid
Crystals
Publication details, including instructions for
authors and subscription information:
http://www.tandfonline.com/loi/gmcl20
Characterization of
Acetylacetonato-
bis-(2-(4-amino-2-
hydroxyphenyl)benzthiazole)
Complex
Sung-Hoon Kim a , Byung-Soon Kim b & Young-A Son b
a Department of Textile System Engineering ,
Kyungpook National University , Daegu, South Korea
b BK21 FTIT, Department of Organic Materials and
Textile System Engineering , National Chungnam
University , Daejeon, South Korea
Published online: 22 Jul 2010.
To cite this article: Sung-Hoon Kim , Byung-Soon Kim & Young-A Son (2009)
Characterization of Acetylacetonato-bis-(2-(4-amino-2-hydroxyphenyl)benzthiazole)
Complex, Molecular Crystals and Liquid Crystals, 498:1, 151-157, DOI:
10.1080/15421400802615402
To link to this article: http://dx.doi.org/10.1080/15421400802615402
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the
information (the “Content”) contained in the publications on our platform.
However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness,
or suitability for any purpose of the Content. Any opinions and views
expressed in this publication are the opinions and views of the authors, and
are not the views of or endorsed by Taylor & Francis. The accuracy of the

Content should not be relied upon and should be independently verified with
primary sources of information. Taylor and Francis shall not be liable for any
losses, actions, claims, proceedings, demands, costs, expenses, damages,
and other liabilities whatsoever or howsoever caused arising directly or
indirectly in connection with, in relation to or arising out of the use of the
Content.
This article may be used for research, teaching, and private study purposes.
Any substantial or systematic reproduction, redistribution, reselling, loan,
sub-licensing, systematic supply, or distribution in any form to anyone is
expressly forbidden. Terms & Conditions of access and use can be found at
http://www.tandfonline.com/page/terms-and-conditions

Mol. Cryst. Liq. Cryst., Vol. 498, pp. 151–157, 2009
Copyright # Taylor & Francis Group, LLC
ISSN: 1542-1406 print=1563-5287 online
DOI: 10.1080/15421400802615402
Characterization of Acetylacetonato-bis-(2-(4-amino-2-
hydroxyphenyI)benzthiazole) Complex
Sung-Hoon Kim1, Byung-Soon Kim2, and Young-A Son2
1Department of Textile System Engineering, Kyungpook National
University, Daegu, South Korea
2BK21 FTIT, Department of Organic Materials and Textile System
Engineering, National Chungnam University, Daejeon, South Korea
Organic luminescent materials have received great attentions due to their
potential application subjects onto full color image displays such as mobile phones,
PDA and etc. In the present work, we synthesized new electroluminescence
material such as acetylacetonato-bis-[2-(4-amino-2-hydroxyphenyl)benzthiazole]
aluminum complex fluorescent dye. The spectroscopic characteristics and the flu-
orescent properties of this dye molecule were characterized by UV-Vis absorption
and PL spectra. In addition, the synthesized dye moiety was discussed using the
theoretical molecular calculation technique in terms of the molecular interatomic
distance and HOMO=LUMO levels.
Keywords: aluminum complex; benzthiazole; fluorescent; organic luminescent material;
PL spectra
INTRODUCTION
Recently, organic luminescent materials have received great
attentions due to their attractive characteristics and potential appli-
cation areas [1–4]. Since the first reported organic light-emitting
device using tris-(8-hydroxyquinoline) aluminum (Alq3) was introdu-
ced, many efforts have been focused on the syntheses of new organic
materials and have achieved great performance on EL device [5].
For the emitting material, the dye metal complex is one of the most
This research was supported by the Program for the Training of Graduate Students
in Regional Innovation which was conducted by the Ministry of Commerce Industry and
Energy of the Korean Government.
Address correspondence to Prof. Young-A Son, BK21 FTIT, Department of Organic
Materials and Textile System Engineering, Chungnam National University, Gung-dong,
Yuseong-gu, Daejeon 305-764, Korea (ROK). E-mail: yason@cnu.ac.kr
151

152
S.-H. Kim et al.
widely used subject in the light-emitting diode due to the properties of
high fluorescence, thermal stability and excellent electron-transport-
ing mobility [6–8].
In this context, we have synthesized new luminescence metal
complex such as acetylacetonato-bis-[2-(4-amino-2-hydroxyphenyl)-
benzthiazole] aluminum complex fluorescent dye. Using DMol3
program, the energy level, atomic distance and absorption spectra
expectation were calculated and compared with the synthesized moi-
ety. The spectroscopic characteristics and the fluorescent properties
of this dye molecule were examined and determined.
EXPERIMENTAL
Synthesis
As presented in Scheme 1(a), p-aminosalicylic acid (0.998 g, 6.52 mmol)
and o-aminothiophenol (0.816 g, 6.52 mmol) added in 20 g of polypho-
sphoric acid was heated at 200ꢀC with constant stirring. After 3 h,
the reaction was quenched into the ice water and being stirred for
24 h. The formed precipitate solution was adjusted to the neutral pH
condition using 1% sodium carbonate solution. After 3 h, the mixture
was filtrated with distilled water at several times and dried in oven at
40ꢀC. Yield 38.84% (0.614 g); calculated for C13H10N2OS: C, 64.44; H,
4.16; N, 11.56; S, 13.23. Found: C, 64.54; H, 4.03; N, 11.52; S, 12.62.
SCHEME 1 Synthetic route of metal complex.

Characterization of acetylacetonato-bis Complex
153
Synthesis of acetylacetonato-bis-[2-(4-amino-2-hydroxyphenyl)
benzthiazole] aluminum complex was shown in Scheme 1(b).
A1C13Á6H2O (0.8 g, 3.3 mmol) dissolved in 2.5 ml water was added into
acetyl acetone (1 g, 9.9 mmol) and solution of potassium hydroxide
(0.56 g, 9.9 mmol) in 5 ml water. Into the formed solution, 2-(4-amino-
2-hydroxyphenyl) benzthiazole (I) (1.6 g, 6.6 mmol) in 75 ml benzene
was dropped. The mixture was heated at reflux with constant stirring.
After 2 h, the reaction was cooled to room temperature and the mix-
ture was filtrated with benzene at several times and dried in vacuum.
Yield 20.78% (0.417 g); calculated for C31H25AlN4O4S2: C, 61.17; H,
4.14; N, 9.20; S, 10.54. Found: C, 58.11; H, 3.87; N, 10.19; S, 11.65.
Measurements
PL spectra were recorded with Shimadzu RF-5301 Spectrofluorophot-
ometer. Elemental analyses were recorded with a Carlo Elba Model
1106 analyzer. Themogravimetric analysis (TGA) was conducted using
TGA-2050 under nitrogen gas at a heating 20ꢀC=min.
RESULTS AND DISCUSSION
The UV-Vis absorption and PL spectra of dye (I) and its aluminum com-
plex dye (II) in chloroform are shown in Figures 1 and 2, respectively.
FIGURE 1 UV-Vis absorption spectra of dye (I) and its aluminum complex
dye (II).

154
S.-H. Kim et al.
FIGURE 2 PL spectra of dye (I) and its aluminum complex dye (II).
The UV-Vis absorption peaks of dye (I) and dye (II) were obtained at
350 nm. The emission spectra of dye (I) and its aluminum complex dye
(II) were observed at 500nm and 495 nm. For the metal complex dye mol-
ecule, it is proposed that the effect of the metal ion within the dye
structure is to increase conformational rigidity and decrease the p-pÃ
energy gap [9].
Furthermore, the molecular structural calculation and absorption
spectral expectation were investigated using modeling calculation
software. All the theoretical calculations were performed by Dmol3
program in the Materials Studio 4.2 package [10,11] which was the
quantum mechanical code using density functional theory and was
then used for spectroscopic calculations. Perdew-Burke-Ernzerhof
(PBE) function of generalized gradient approximation (GGA) level
[12] with double numeric polarization basis set [10] was used to calcu-
late the energy level of the frontier molecular orbital. The optimized
molecular structure is shown in Figure 3. The molecular interatomic
˚
distances between Al and the thiazole N are 1.93 and 4.19 A, while
the distance between central Al and carbonyl O in acetylacetonate is
˚
4.23 A. The HOMO and LUMO levels of the dye are À4.351 and
À2.815 eV, respectively. In addition, the calculated absorption wave-
lengths are collected in Figure 4. The calculated first transition
absorption (kmax:360 nm) is relatively compatible with observed
absorption spectra from the finding of Figure 1. In this context, it is
proposed that this theoretical calculation approach could be beneficial

Characterization of acetylacetonato-bis Complex
155
FIGURE 3 Optimized molecular conformation using DMol3 modeling calcu-
lation.
to expect the spectral properties of the other designed organic
luminescent compounds.
Thermal stability of the synthesized dye (II) was evaluated by TGA
with the initial degradation temperature. The initial degradation
behavior of the synthesized dye in the range of 50–700ꢀC is shown in
Figure 5. From the result, it is proposed that the degradation tempera-
ture was observed at 210–300ꢀC with 70% of corresponding weight
loss and that this aluminum complex dye (II) was stable at the tem-
perature range of 210ꢀC.
FIGURE 4 Calculated first transition absorption spectrum.

156
S.-H. Kim et al.
FIGURE 5 Thermal analysis for the dye (II) by TGA.
CONCLUSIONS
In this study, we have synthesized electroluminescence material,
namely acetylacetonato-bis-[2-(4-amino-2-hydroxyphenyl) benzthia-
zole] aluminum complex fluorescent dye and have observed its PL
spectra. The emission spectra of dye (I) and its aluminum complex
dye (II) were obtained at 500 nm and 495 nm. Aluminum complex
dye (II) compared with dye (I) showed strong fluorescence intensity.
Satisfactory thermal stability of acetylacetonato-bis-[2-(4-amino-2-
hydroxyphenyl) benzthiazole] aluminum complex dye was determined
by TGA analysis.
REFERENCES
[1] Yang, K. S., Shin, H. K., Kim, C., & Kwon, Y. S. (2005). Synthetic Metals, 152, 245.
[2] Jang, Y. K., Kim, D. E., Kim, W. S., Kwon, O. K., Lee, B. J., & Kwon, Y. S. (2006).
Colloids and Surfaces A, 331, 248–245.
[3] Kim, S. H., Yoon, S. H., Kim, S. H., & Han, E. M. (2005). Dyes and Pigments, 64, 45.
[4] Sung, H. H., Kim, I. H., Byun, K. N., & Yoo, H. S. (2005). Current Applied physics,
5, 345.
[5] Du, N., Mei, Q., & Lu, M. (2005). Synthetic Metals, 14, 193.
[6] Thomsen, D. L., Phely-Bobin, T., & Papadimitrakopoulos, F. J. (1998). Am. Chem.
Soc., 120, 6177.
[7] Schmitz, C., Schmidt, H. W., & Thelakkat, M. (2000). Chem. Mater., 12, 3012.
[8] Ghedini, M., La Deda, M., Aiello, I., & Grisolia, A. (2003). Synthetic Metals,
138, 189.

Characterization of acetylacetonato-bis Complex
157
[9] Zhang, C., Guo, R., Wu, Q., & Zhang, H., (2007). Reactive & Functional Polymers,
67, 408.
[10] Delley, B. (1990). J. Chem. Phys., 92, 508.
[11] Delley, B. (2000). J. Chem. Phys., 113, 7756.
[12] Boese, A. D. & Handy, N. C. (2001). J. Chem. Phys., 114, 5497.