Red fluorescence thin film based on a strong push-pull dicyanoisophorone system

Article abstract of DOI:10.1016/j.dyepig.2014.08.014

Dicyanoisophorone derivatives (1-3), which contain a strong push-pull chromophores system, have been prepared by a two-step condensation reaction, and their fluorescence in solution, polymeric thin film and pure solid state are measured. It is found that 1-3 exhibit no or weak fluorescence in both solution and pure solid state, but strong red fluorescence in polymeric thin film. Mechanism study implies that the enhanced fluorescence of 1-3 in polymeric thin film results from the restriction of intramolecular vibrational and rotational motions. In addition, it is also found that the polarity of polymeric matrix has influence over the fluorescence of dicyanoisophorone derivatives, using PMMA as polymeric matrix, a fluorescent thin film with a strong red emission is obtained.

Full text of DOI:10.1016/j.dyepig.2014.08.014

Accepted Manuscript
Red fluorescence thin film based on a strong push-pull dicyanoisophorone system
Zheng Gao, Xu Zhang, Yi Chen
PII:
S0143-7208(14)00338-6
10.1016/j.dyepig.2014.08.014
DYPI 4498
DOI:
Reference:
To appear in: Dyes and Pigments
Received Date: 9 July 2014
Revised Date: 13 August 2014
Accepted Date: 14 August 2014
Please cite this article as: Gao Z, Zhang X, Chen Y, Red fluorescence thin film based on a strong push-
pull dicyanoisophorone system, Dyes and Pigments (2014), doi: 10.1016/j.dyepig.2014.08.014.
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ACCEPTED MANUSCRIPT
Red fluorescence thin film based on a strong push-pull
dicyanoisophorone system
Zheng Gaoa,b, Xu Zhanga and Yi Chena*
aKey Laboratory of Photochemical Conversion and Optoelectronic Materials,
Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences,
Beijing, 100190, China. Fax: 86 10 6487 9375; Tel: 86 10 8254 3595; E-mail:
yichen@mail.ipc.ac.cn
bUniversity of Chinese Academy of Sciences, Beijing 100049, China
Abstract: Dicyanoisophorone derivatives (1-3), which contain a strong push-pull
chromophores system, have been prepared by a two-step condensation reaction, and
their fluorescence in solution, polymeric thin film and pure solid state are measured. It
is found that 1-3 exhibit no or weak fluorescence in both solution and pure solid state,
but strong red fluorescence in polymeric thin film. Mechanism study implies that the
enhanced fluorescence of 1-3 in polymeric thin film results from the restriction of
intramolecular vibrational and rotational motions. In addition, it is also found that the
polarity of polymeric matrix has influence over the fluorescence of
dicyanoisophorone derivatives, using PMMA as polymeric matrix, a fluorescent thin
film with a strong red emission is obtained.
Keywords: dicyanoisophorone derivatives, red fluorescence, polymeric matrix, thin
film, push-pull chromophores system, synthesis.
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1. Introduction
Solid-state fluorescent dyes have created considerable interest in recent years
owing to their wide potentials in material science [1-6] and biology [7-12]. From the
standpoint of practical application, highly efficient solid-state emission is desired.
However, most organic fluorophores exhibit strong fluorescence in dilute solutions
but no or weak fluorescence in the solid state as a consequence of the tight molecular
packing in the pure microcrystalline state or amorphous solid phase (thin film) [13,
14]. It has been revealed that strong intermolecular π-π interaction is a principal factor
of fluorescence quenching in the solid state [15,16].
Dicyanoisophorone derivatives with a push-pull chromophores system have
attracted considerable attention due to their red fluorescence in both solution and in
solid-state [17-21]. It has reported that dicyanoisophorone derivatives show unique
enhanced emission rather than a fluorescence quenching upon aggregation in the solid
state, the enhanced emission results from the impressive aggregation-induced
emission (AIE) or aggregation-induced enhanced emission (AIEE) in which the
mechanisms include the effects of intramolecular planarization or restricted
intramolecular vibrational and rotational motions in the solid state or of specific
aggregation (H- or J-aggregation) or certainly a combination of all those effects
depended on different structures and substituents [18,21]. Recently, we have found
that the fluorescence of dicyanoisophorone derivatives with a push-pull chromophores
system depend strongly not only on the chromophore used, but also on its
environment [22]. Organic fluorescent dyes, which can exhibit fluorescence changes
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upon the change of environment such as the formation of aggregates in pure solid
state or doped in polymeric thin film, can be one of the most promising materials for
the construction of desirable solid state fluorescent system [23-25]. To further
understand the fluorescence behavior of dicyanoisophorone derivatives and to
develop dicyanoisophorone-based solid state fluorescence system, we herein examine
the fluorescence of dicyanoisophorone derivatives in polymeric thin film. Three
dicyanoisophorone derivatives 1-3 (Scheme 1) are prepared, it is found that 1-3 show
strong red emission in polymeric thin film, moreover, both emission wavelength and
intensity are increased with the increase of the polarity of media. The mechanism
implied that enhanced emission resulted from the inhibition of intramolecular
vibrational and rotational motions of 1-3 in polymeric thin film.
<Scheme 1>
2. Experimental
2.1. General
1H and 13C NMR spectra were recorded at 400 and 100 MHz, respectively, with
TMS as an internal reference. MS spectra were recorded with TOC-MS spectrometer,
respectively. UV absorption spectra and fluorescence spectra in solution were
measured with an absorption spectrophotometer (Hitachi U-3010) and a fluorescence
spectrophotometer (F-2500), respectively. Fluorescence quantum yields in solid state
were measured with a fluorescence spectrophotometer (Edinburgh Instruments
FLS-920). Solid absorption spectra were measured with UV-VIS-NIR
spectrophotometer (Cray 50000, Varian). All chemicals for synthesis were purchased
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from commercial suppliers, and solvents were purified according to standard
procedures. Reaction was monitored by TLC silica gel plates (60F-254). Column
chromatography was performed on silica gel (70-230 mesh).
2.2. Chemical
The synthetic routes for target compounds 1-3 were presented in Scheme 2, and the
detailed procedures were as follows: (a) To a solution of isophorone (3.8g, 27.6 mmol)
and malononitrile (1.82g, 27.6 mmol) in dry ethanol (150 mL) was added piperidine
(23 mg, 0.276 mmol). The solution was stirred at 60°C till starting material
disappeared (detected by TLC plate). After cooling to room temperature, the solution
was slowly poured into water (200 mL) and the precipitated solid was filtered.
Recrystallization from heptane afforded 2-(3,5,5-trimethylcyclohex-2-enylidene)
malononitrile as a brown solid. Yield: 4.5 g (90%). M.p. 73-75°C. 1H NMR (CDCl3):
13
δ (ppm) 6.60 (s, 1H), 2.53 (s, 2H), 2.14 (s, 2H), 2.01 (s, 3H), 1.32 (s, 6H). C NMR
(CDCl3): δ (ppm) 170.3, 161, 120.2, 113.1, 76.4, 45.6, 42.3, 32.4, 27.5, 25.1. (b)
Under argon, 2-(3,5,5-trimethylcyclohex-2-enylidene) malononitrile (1.0 equiv.) and
corresponding aromatic aldehydes (1.0 equiv.) were dissolved in dry acetonitrile (100
mL). Piperidine (0.01 equiv) was added and the solution was stirred at 40 °C till
starting material disappeared (detected by TLC plate). The solution was concentrated
and the product was purified by flash column chromatography (elute: petroleum ether
/ ethyl acetate = 10 / 1, v/v).
1. Yield: 50%. 1H NMR (400 MHz, CDCl3): δ = 7.38 (d, J = 8.9 Hz, 2H), 7.01 (d, J
= 16 Hz, 1H), 6.76 (d, J = 16 Hz, 1H), 6.73 (s, 1H), 6.64 (d, J = 8.9 Hz, 2H), 3.12 (s,
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6H), 2.74 (s, 2H), 2.65 (s, 2H), 1.06 (s, 6H). 13C NMR (100 MHz, CDCl3): δ = 169.2,
155.3, 151.2, 138.3, 129.5, 129.4, 124.4, 121.4, 114.1, 113.4, 112.3, 75.7, 42.9, 40.3,
39.2, 31.8, 28.1. HRMS (EI) calcd for C21H24N3 (M++1): 318.1970. Found: 318.1889.
Anal. Calcd. For C21H23N3: C, 79.46; H, 7.30. Found: C, 79.65; H, 7.18.
2. Yield: 55%. 1H NMR (400 MHz, CDCl3): δ = 7.39 (d, J = 8.0 Hz, 1H), 7.36 (d,
J = 8.0 Hz, 1H), 6.90 (d, J = 16.0 Hz, 1H), 6.72 (s, 1H), 6.31 (d, J = 8.0 Hz, 1H), 6.02
(d, J = 2.0 Hz, 1H), 3.40-3.35 (q, 4H), 2.56 (s, 2H), 2.50 (s, 1H), 2.47 (s, 2H), 1.19 (t,
J1 = 8.2 Hz, J2 = 7.2 Hz, 6H), 1.06 (s, 6H). 13C NMR (100 MHz, CDCl3): δ = 159.8,
156.3, 149.2, 136.9, 135.3, 131.1, 130.5, 128.4, 124.4, 116.4, 113.6, 112.7, 78.4, 42.1,
41.3, 40.5, 37.8, 31.8, 28.2. HRMS (EI) calcd for C23H27N3O: 361.2154. Found:
361.2168.
3. Yield: 60%. 1H NMR (400 MHz, CDCl3): δ = 7.41 (d, J = 8.0 Hz, 1H), 7.35 (d, J
= 8.0 Hz, 1H), 6.91 (d, J = 16.0 Hz, 1H), 6.70 (s, 1H), 6.32 (d, J = 8.0 Hz, 1H), 6.01
(d, J = 2.0 Hz, 1H), 4.38-4.32 (q, 2H), 3.39-3.34 (q, 4H), 2.57 (s, 2H), 2.49 (s, 2H),
1.42 (t, J1 = 7.2 Hz, J2 = 6.8 Hz, 3H), 1.18 (t, J1 = 8.2 Hz, J2 = 7.2 Hz, 6H), 1.05 (s,
6H). 13C NMR (100 MHz, CDCl3): δ = 158.8, 155.3, 151.0, 136.9, 134.5, 131.1,
129.8, 128.4, 124.3, 115.4, 113.6, 112.2, 78.8, 78.2, 65.0, 41.3, 40.8, 37.3, 31.7, 28.2,
14.8. HRMS (EI) calcd for C25H31N3O: 389.2467. Found: 389.2471.
<Scheme 2>
2.3 The preparation of polymeric-fluorescent dye thin film.
PMMA and PS thin films were prepared as follows: 1-3 (1.0 mg, 0.5 mg, 0.25 mg)
was dissolved in 2.0 mL of a PMMA–cyclohexanone solution (13%, w/w) or 2.0 ml
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of a PS-toluene solution (5%, w/w). A film was obtained by spin coating a 0.35 ml
PMMA-cyclohexanone solution or a 0.35 ml of a PS-toluene solution on quartz glass
(size: 2.5 cm × 1.2 cm), and dried in air at room temperature. The concentration of 1-3
in PMMA thin film is ca 0.1%, 0.2% and 0.4% (w/w), and in PS thin film is ca 0.25%,
0.5% and 1.0% (w/w).
3. Results and discussion
3.1.Optical properties of dicyanoisophorone derivatives 1-3 in solution
The optical properties of dicyanoisophorone derivatives 1-3 are measured in
different solution (20 ꢀM) and photophysical data are reported in Table 1.
Absorbance and fluorescence spectra of compound 3 measured at room temperature
in different solvents are shown in Fig. 1 and Fig. 2, respectively. Absorption data are
characteristic of induced charge transfer transitions in push-pull dipolar molecules. It
was found that the maximum absorption shifted from 480 nm to 504 nm when
electron-donating substituent in benzene ring changed from H (1) to OCH3 (3) in
cyclohexane solution, which is in agreement with the assumption of intramolecular
charge transfer (ICT), and an ICT enhancement results in the bathochromic shift of
the absorption bands. In addition, a positive solvatochromism was observed for 1-3 in
different solvent. As presented in Fig. 1, the maximum absorption shifted from 504
nm to 554 nm (3) when solvent changed from cyclohexane to DMSO. The
solvatochromism is characteristic of induced charge transfer transitions in push-pull
dipolar molecules, which is in agreement with this attribution and in agreement with
reported in this type of molecules [18].
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<Table 1>
< Fig. 1>
<Fig. 2>
The fluorescence investigation of 1-3 in solvents exhibits that 1-3 show very weak
fluorescence in solution, and small quantum yields (ϕf) are obtained using rubrene (ϕf
= 0.27, in MeOH) as reference [26] (Table 1). Further examination finds that 1-3
show prominent solvent polarity dependent changes in their emission characteristics.
It was found that the emission bands of 1-3 were significant bathochromic shift with
increasing the polarity of solvents, the maximum emission shifted from 518 nm to 659
nm when solvent changed from cyclohexane to DMSO (Fig. 2). Moreover, a
significant dependence of quantum yield with the polarity of solvent was observed, as
presented in Table 1, the quantum yields of 1-3 were increased with the increase of
the polarity of solvents, which is different from the common results in which the
emission intensity of ICT compounds such as styryl dyes (comprised by strong donor
and acceptor moieties joined by π-conjugation in a single molecule) is usually
decreased with increase of polarity of solvents [27-29]. A possible explanation is that
the styryl dyes with strong ICT character are much more polar in nature in excited
states than that in ground states, the dye molecules in the excited state adopt a planar
or quasi-planar conformation in large polarity solvent such that a large extent of
charge is transferred from the strong electron donating moiety to the strong electron
acceptor via the participation of the styryl π-conjugation, resulting in the enhancement
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of emission intensity [30].
3.2. Fluorescence of dicyanoisophorone derivatives 1-3 in polymeric thin film
Both absorption and fluorescence of dicyanoisophorone derivatives 1-3 in
polymeric thin film are measured. Relevant photophysical data are summarized in
Table 2, and absorption and fluorescence spectral of dicyanoisophorone derivative 3
are shown in Figs. 3 and 4. It was found that the maximum absorption of 3 shifted
from 524 nm to 540 nm when polymeric matrix changed from polystyrene (PS) to
poly methyl methacrylate (PMMA), which suggested that ICT of 3 was increased
with the increase of the polarity of polymeric matrix, that is in agreement with the
result in solution. Similar results were obtained with 2 and 3 in polymeric thin film.
Solid-state fluorescence of 1-3 showed that all compounds exhibited strong
fluorescence emission in polymeric thin film. The quantum yields of 1-3 in different
polymeric thin film were measured by an integrating sphere and the largest quantum
yield of ϕ = 0.64 was obtained (Table 2). As compared to solution, the quantum yields
of 1-3 in polymeric thin film are much larger than these in solution. Moreover, the
emission bands of 1-3 were also significant bathochromic shift with increasing the
polarity of polymeric matrix, the maximum emission of 3 shifted from 605 nm to 630
nm when polymeric matrix changed from PS to PMMA.
<Table 2>
<Fig. 3>
<Fig. 4>
3.3. A possible mechanism for enhanced fluorescence of 1-3 in polymeric thin film
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To insight into a possible mechanism for the enhancement of fluorescence of
dicyanoisophorone derivatives 1-3 in polymeric thin film, the aggregation-induced
emission behaviors of 1-3 in polymeric thin film are investigated. It was found that
the emission wavelength was red-shifted, but the fluorescence intensity was decreased
when the concentration of 1-3 was increased. As presented in Figs. 5 and 6, upon
increasing the concentration of 3 from 0.1% to 0.4% (w/w) in PMMA film or from
0.25% to 1.0% (w/w) in PS film, the emission wavelength had 10 nm red-shift for
PMMA film or 8 nm for PS film, and at the same time, the fluorescence intensity was
decreased about 35% in PMMA film and 74% in PS film, respectively. Similar results
were obtained when 3 was replaced by 1 and 2. Red-shift in emission wavelength and
decrease in fluorescence intensity with the increase of concentration implied that the
aggregation of 1-3 in polymeric thin film did not increase the fluorescence but
decrease the fluorescence, the quenched fluorescence probably resulted from the
significant molecular interactions and self-absorption. In addition, control experiment
showed that no or a very weak fluorescence (ϕf ≤ 0.005) was detected upon excitation
1-3 in pure solid state (amorphous powder) due to the self-absorption resulted from
the aggregation in the solid state. As shown in Fig. 7, the absorption of 3 in pure solid
state red-shifted to near infrared region (~1000 nm), such a long absorption
wavelength covered the emission band of 3, and caused strong re-absorption which
resulted in the fluorescence quench.
<Fig. 5>
<Fig. 6>
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<Fig. 7>
The enhanced emission of 1-3 in polymeric thin film probably results from the
restriction of intramolecular vibrational and rotational motions. To confirm the
suggestion, the fluorescence of 1-3 in solution with different viscosity and different
temperature are conducted. Control experiments showed that the fluorescence
intensity of 1-3 in mixed EtOH-glycerol solution was increased when the viscosity of
solution was increased. It was found that the fluorescence intensity of 3 was increased
with increase of ratio of glycerol. As shown in Fig. 8, the fluorescent intensity of 3
was enhanced by 12% with a slight red-shift when added glycerol in mixed solvent
was up to 10% (volume ratio). Similar results were obtained with 1 and 2. Besides,
the effect of temperature on the fluorescence of 1-3 in solution revealed that a
significant decrease in fluorescence when the temperature of solution was more than
30 °C. As shown in Fig. 9, the fluorescence of 1 was decreased by 28% when the
temperature was increased from 30 °C (ambient temperature) to 50 °C. On the
contrary, the fluorescence was increased by 17% when the temperature was dropped
to 10 °C. Both viscosity-depended emission and temperature-depended emission
suggested that the enhancement of fluorescence was probably from the restriction of
intramolecular vibrational and rotational motions.
<Fig. 8>
<Fig. 9>
4. Conclusions
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In summary, red fluorescence thin film based on dicyanoisophorone derivatives with a
strong push-pull chromophores system has been developed. It has demonstrated that
dicyanoisophorone derivatives with a strong push-pull chromophores system exhibit
strong red fluorescence in polymeric thin film due to the restricted intramolecular
vibrational and rotational motions. It has also demonstrated that the polarity of
polymeric matrix affects the fluorescence of dicyanoisophorone derivatives, with
large polar polymeric matrix, strong and red-shifted emission is obtained.
Red fluorescence thin film with λem = 630 ~ 650 nm is potential application in
light-conversion for plants growing-up. Light ecology research shows that blue light
region of 400 ~ 480 nm and red light region of 630 ~ 680 nm are good for
photosynthesis. Organic fluorescence dyes have good compatibility with polymer
medium and are easy processing. Fluorescent polymeric thin film with high
photo-stable and strong red emission is desired. Further photo-stable studies as well as
applications of the present fluorescent dyes to light-conversion for photosynthesis are
in progress.
Acknowledgments
This work was supported by the National Natural Science Foundation of China
(No 91123032 and No 21302197).
References
[1] Tang CW. Organic electroluminescent diodes. Appl Phys Lett 1987;51:913-5.
[2] Friend RH, Gymer RW, Holmes AB, Burroughes JH, Marks RN, Taliani C, et al.
Electroluminescence in conjugated polymers. Nature 1999;397:121-8.
11

ACCEPTED MANUSCRIPT
[3] Dong YQ, Lam JWY, Qin AJ, Liu JZ, Li Z, Tang BZ. Excimer laser annealing of
silicon nanowires. Appl Phys Lett 2007;91:11111-3.
[4] Shi C, Guo Z, Yan Y, Zhu S, Xie Y, Sheng Y, Zhao Y, Zhu W, Tian H.
Self-assembly solid-state enhanced red emission of quinolinemalonoitrile: optical
waveguides and stimuli response. ACS Appl Mater Interfaces 2013;5:192-8.
[5] Hong YN, Lam JWY, Tang BZ. Aggregation-induced emission: phenomenon,
mechanism and applications. Chem Commun 2009;4332-5.
[6] Langhals H. Krotz O. Polborn K. Mayer P. A Novel fluorescent dye with strong
anisotropic solid-state fluorescence, small Stokes shift, and high photostability.
Angew Chem Int Ed 2005;44:2427-8.
[7] Wang M, Zhang G, Zhang D, Zhu D, Tang BZ. Fluorescent bio/chemosensors
based on silole and tetraphenylethene luminogens with aggregation-induced emission
feature. J Mater Chem 2010;20:1858-67.
[8] Lu H, Xu B, Dong Y, Chen F, Li Y, Li Z, He J, Li H, Tian W. Novel fluorescent
pH sensors and a biological probe based on anthracene derivatives with
aggregation-induced emission characteristics. Langmuir 2010;26:6838-44.
[9] Liu Y, Deng CM, Tang L, Qin AJ, Hu RR, Sun JZ, Tang BZ. Specific detection of
D-glucose by a tetraphenylethene-based fluorescent sensor. J Am Chem Soc
2011;133:660-3.
[10] Guo Z, Zhu W, Tian H. Hydrophilic copolymer bearing
dicyanomethylene-4-pyran moiety as fluorescent film sensor for Cu2+ and
pyrophosphate anion. Macromolecules 2010;43:739-44.
12

ACCEPTED MANUSCRIPT
[11] Botzung-Appert E, Monnier V, Duong TH, Pansu R, Ibanez A. Polyaromatic
luminescent nanocrystals for chemical and biological sensors. Chem Mater 2004;
16:1609-11.
[12] Redon S, Massin J, Pouvreau S, De Meulenaere E, Clays K, Queneau Y,
Andraud C, Girard-Egrot A, Bretonniere Y, Chambert S. Red emitting neutral
fluorescent glycoconjugates for membrane optical imaging. Bioconjugate chem 2014;
25:773−87.
[13] An BK, Kwon SK, Jung SD, Park SY. Enhanced emission and its switching in
fluorescent organic nanoparticles. J Am Chem Soc 2002;124:14410-5.
[14] Tracy HJ, Mullin JL, Klooster WT, Martin JA, Haug J, Wallace S, Rudloe I,
Watts K. Enhanced photoluminescence from group 14 metalloles in aggregated and
solid solutions. Inorg Chem 2005;44:2003-11.
[15] Yeh, H.-C.; Wu, W.-C.; Wen, Y.-S.; Dai, D.-C.; Wang, J.-K.; Chen, C.-T.
Derivative of α,β-dicyanostilbene:ꢁ convenient precursor for the synthesis of
diphenylmaleimide compounds, E−Z isomerization, crystal structure, and solid-state
fluorescence. J Org Chem 2004;69:6455-62.
[16] Ooyama, Y.; Yoshida, K. Heterocyclic quinol-type fluorophores: solid-state
fluorescence change in crystals of benzo[b]naphtho[1,2-d]furan-6-one-type
fluorophore upon inclusion of organic solvent molecules
2008;15:2564-70.
. Eur J Org Chem
[17] Redon S, Massin J, Pouvreau S, De Meulenaere E, Clays K, Queneau Y,
Andraud C, Girard-Egrot A, Bretonniere Y, Chambert S. Red emitting neutral
13

ACCEPTED MANUSCRIPT
fluorescent glycoconjugates for membrane optical imaging. Bioconjugate chem 2014;
25:773−87.
[18] Massin J, Dayoub W, Mulatier JC, Aronica C, Bretonni_ere Y, Andraud C.
Near-infrared solid-state emitters based on isophorone: synthesis, crystal structure
and spectroscopic properties. Chem Mater 2011;23:862-73.
[19] Ke W, Wang L, Song B, Yang J, Tian Y, Kan Y, Tao X, Jiang M, Synthesis and
properties of a meso-tetraphenylporphyrin and its Zn (II) complex with a
dicyanoisophorone borne by double bond in the β pyrrolic position. Inorg chem
commun 2011;14:1311-3.
[20] Massin J, Parola S, Andraud C, Kajzar F, Rau I, Enhanced fluorescence of
isophorone derivatives in DNA based materials. Opt Mater 2013;35:1810-6.
[21] Wang L-K, Shen Y-F, Li H-J, Zhao X-Y, Zheng Z, Zhou HP, Wu J-Y, Tian Y-P,
Six d10 metal complexes containing multidentate dicyanoisophoronetriazolyl
derivative: Structures and luminescent properties. J Mol Struct 2014;1068:182-8.
[22] Zhang X, Chen Y. Synthesis and fluorescence of dicyanoisophorone derivatives.
Dyes and pigments 2013;99:531-6.
[23] Dubuisson E, Monnier V, Sanz-Menez N, Boury B, Usson Y, Pansu RB, Ibanez
A. Brilliant molecular nanocrystals emerging from sol–gel thin films: towards a new
generation of fluorescent biochips. Nanotechnology 2009;20:315301-7.
[24] Scott, J. L.; Yamada, T.; Tanaka, K. Guest specific solid-state fluorescence
rationalised by reference to solid-state structures and specific intermolecular
interactions. New J Chem 2004;28:447-50.
14

ACCEPTED MANUSCRIPT
[25] Ooyama Y, Nagano S, Yoshida K. Drastic solid-state fluorescence enhancement
behaviour of imidazo[4,5-a]-naphthalene-type fluorescent hosts upon inclusion of
polyethers and tert-butyl alcohol. Tetrahedron 2009;65:1467-74.
[26] Boens N, Qin W, Basari N, Hofkens J, Ameloot M, Pouget J, Lefevre JP, Valeur
B, Gratton E, vandeVen M, Silva NDJ, Engelborghs Y, Willaert K, Sillen A, Visser
AJWG, van Hoek A, Lakowicz JR, Malak H, Gryczynski I, Szabo AG, Krajcarshi DT,
Tamai N, Miura A. Fluorescence lifetime standards for time and frequency domain
fluorescence spectroscopy. Anal Chem 2007;79:2137-49.
[27] Nguyen Pham TH, Clarke RJ. Solvent dependence of the photochemistry of the
styrylpyridinium dye RH421. J Phys Chem B 2008;112:6513-20.
[28] Huang Y, Cheng T, Li F, Luo C, and Huang CH, Cai Z, Zeng X, and Zhou J.
Photophysical studies on the mono- and dichromophoric hemicyanine dyes II. solvent
effects and dynamic fluorescence spectra study in chloroform and in LB films. J Phys
Chem B 2002;106:10031-40.
[29] Gruen H, Gorner H. Trans - Cis photdsomerizatlon, fluorescence, and relaxation
phenomena of trans-4-nitro-4’-(diakylamlno)stilbenes and analogues with a
nonrotatable amino group. J Phys Chem 1989;93:7144-52.
[30] Shaikh M, Mohanty J, Singh PK, Bhasikuttan AC, Rajule RN, Satam VS,
Bendre SR, Kanetkar VR, Pal H. Contrasting solvent polarity effect on the
photophysical properties of two newly synthesized aminostyryl dyes in the lower and
in the higher solvent polarity regions. J Phys Chem A 2010;114:4507–4519.
15

ACCEPTED MANUSCRIPT
Table 1. Spectroscopic data of compounds 1-3 in solution a
Compds
Solvent
λmax(nm)
ε (l cm-1mol-1)
λem(nm)
ϕf
ꢀλ(nm)
cyclohexane
CH3CN
480
494
518
506
522
558
504
526
554
31800
27400
26000
29900
26900
31000
41200
39200
37200
576
644
659
578
645
666
576
651
666
0.04
0.08
0.10
0.02
0.04
0.05
0.04
0.08
0.09
95
150
141
72
1
DMSO
cyclohexane
CH3CN
2
3
123
108
72
DMSO
cyclohexane
CH3CN
125
112
DMSO
a
λabs: maximum absorption wavelength, λem: maximum emission wavelength at
ambient temperature, ε: molar absorption coefficients at maximum absorption
wavelength, ϕf: fluorescence quantum yield using rubrene (ϕf = 0.27, in MeOH) as
reference. ꢂλ: Stoke’s shifte calculated by (ꢂλ =λem - λabs nm).
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Table 2. Spectroscopic data of compounds 1-3 in different polymeric thin filma
Compds
polymer
λabs (nm)
λem (nm)
ϕf
ꢀλ(nm)
PMMA
PS
506
500
538
524
540
524
610
580
628
604
630
605
0.64
0.34
0.54
0.28
0.49
0.33
104
80
90
80
90
81
1
PMMA
PS
2
3
PMMA
PS
a
λabs: maximum absorption wavelength, λem: maximum emission wavelength at
ambient temperature, ϕf: measured by an integrating sphere at ambient temperature.
ꢂλ: Stoke’s shifte calculated by (ꢂλ =λem - λabs nm).
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Figures captions
Scheme 1. Chemical structure of target compound.
Scheme 2. General synthetic route for dicyanoisophorone derivatives 1-3.
Fig. 1. The absorption of 3 (20 ꢀM) in different solution.
Fig. 2. The fluorescence of 3 in (20 ꢀM) in different solution.
Fig. 3. The absorption of 3 in different polymeric thin film.
Fig. 4. The fluorescence of 3 in different polymeric thin film.
Fig. 5. The fluorescence of 3 in PMMA thin film with different concentration
(3/PMMA: 0.1%; 0.2%; 0.4% w/w).
Fig. 6. The fluorescence of 3 in PS thin film with different concentration (3/PS:
0.25%; 0.5%; 1.0% w/w).
Fig. 7. Absorption spectral of 3 in pure solid state (amorphous powder).
Fig. 8. Fluorescence spectral change of 3 in mixed solvent (EtOH-glycerol).
Fig. 9. Fluorescence spectral change of 3 in EtOH at different temperature.
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Scheme 1
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Scheme 2
NC
CN
OHC
N
1
N
NC
CN
OHC
HO
N
NC
CN
OH
CN
CN
O
N
2
OHC
C2H5O
N
NC
CN
O
3
N
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Fig. 1
cyclohexane
MeCN
DMSO
0.8
0.6
0.4
0.2
0.0
300
400
500
600
700
wavelength (nm)
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Fig. 2
cyclohexane
MeCN
DMSO
40
30
20
10
0
550
600
650
700
750
800
wavelength (nm)
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Fig. 3
1.6
1.2
0.8
0.4
0.0
PS
PMMA
300
400
500
600
700
wavelength (nm)
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Fig. 4
200
150
100
50
PS
PMMA
0
600
650
700
750
wavelength (nm)
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Fig. 5
80
60
40
20
0
0.4% (w/w)
0.2% (w/w)
0.1% (w/w)
600
650
700
750
wavelength (nm)
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Fig. 6
100
80
60
40
20
0
1.0%
0.5%
0.25%
550
600
650
700
750
wavelength (nm)
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Fig. 7
1.6
1.2
0.8
0.4
0.0
200 300 400 500 600 700 800 900 1000
wavelength (nm)
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Fig. 8
60
50
40
30
20
10
0
0 %
5 %
10 %
600
650
700
750
wavelength (nm)
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Fig. 9
120
100
80
60
40
20
0
10C
30C
50C
600
650
700
750
wavelength (nm)
29