Acid-stimuli-luminescence and carbonyl-proton interaction dependent emission properties of 2,6-biphenyl-4-pyrone crystals

Article abstract of DOI:10.1021/cg200920d

The diversity of hydrogen and ionic bond interactions in 2,6-biphenyl-4-pyrone-acid (BPP-acid) supramolecular systems and the acid-induced luminescence character of BPP was reported. On the basis of X-ray single crystal structure analysis and theoretical calculation, the strong luminescence of BPP-HCl and BPP-TFA (TFA = trifluoroacetic acid) crystals was attributed to the protonation or strong hydrogen bond interactions between the carbonyl group of BPP and the proton of HCl or TFA. Notably, in BPP-TFA crystal the interaction between BPP and TFA displayed a "mixed bond" feature; namely, the bond between carbonyl of BPP and hydroxyl of TFA possesses partial hydrogen bond and partial ionic bond nature. The acid stimuli-luminescence properties of BPP film may offer a potential application in chemical sensors.

Full text of DOI:10.1021/cg200920d

Article
pubs.acs.org/crystal
Acid-Stimuli-Luminescence and Carbonyl-Proton Interaction
Dependent Emission Properties of 2,6-Biphenyl-4-pyrone Crystals
Tianlei Zhou, Tao Jia, Shanshan Zhao, Jianhua Guo, Hongyu Zhang,* and Yue Wang*
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R.
China
S
* Supporting Information
ABSTRACT: The diversity of hydrogen and ionic bond interactions in
2,6-biphenyl-4-pyrone-acid (BPP−acid) supramolecular systems and the
acid-induced luminescence character of BPP was reported. On the basis
of X-ray single crystal structure analysis and theoretical calculation, the
strong luminescence of BPP−HCl and BPP−TFA (TFA = trifluoroacetic
acid) crystals was attributed to the protonation or strong hydrogen bond
interactions between the carbonyl group of BPP and the proton of HCl
or TFA. Notably, in BPP−TFA crystal the interaction between BPP and
TFA displayed a “mixed bond” feature; namely, the bond between
carbonyl of BPP and hydroxyl of TFA possesses partial hydrogen bond
and partial ionic bond nature. The acid stimuli-luminescence properties of
BPP film may offer a potential application in chemical sensors.
Scheme 1. Molecule Structure of 2,6-Biphenyl-4-pyrone
(BPP) and the BPP−Acid Interaction-Dependent
Fluorescent Behavior
INTRODUCTION
■
The exploitation of highly emissive organic materials is of
immense interest due to their intrinsic scientific and
technological applications in the field of optoelectronics.1,2
Furthermore, the organic luminescent materials that are
responsive to external physical and chemical stimuli such as
light-, thermo-, electro-, mechano-, vapo-, etc. offer potential
applications in the fields of sensing, display, and optical
imaging.3−5 For the solid organic materials composed of
different small molecules, the constituent molecules may form
strong intermolecular interactions and assemble into supra-
molecular structures, with the result that the properties of these
materials are often governed by the intermolecular interactions
rather than by individual molecules.6 Although many organic
luminescent materials with stimuli-responsive feature have been
developed, understanding and unraveling the relationship
between the supramolecular structure in the solid state and
emission properties should be focused on the systematic
synthesis and single crystal structure analysis of some model
compounds.
In this contribution, we report an organic molecule 2,6-
biphenyl-4-pyrone (BPP) that exhibits protonation and hydro-
gen-bonding interaction induced luminescence, as shown in
Scheme 1. When BPP was treated with strong acids such as
hydrochloric acid (HCl) or trifluoroacetic acid (TFA) in
solution, the nonemissive solution immediately emits bright
blue emission. In addition, the non-emissive film comprised of
pure BPP could rapidly transform into strong emissive film
upon being exposed to strong acid vapors. The weaker acetic
acid (HOAc) was also employed to check the stimuli-
responsive luminescence property of BPP. The proton donating
ability of acid has a dramatic effect on the luminescent intensity
of the resulting BPP−acid composited systems. Upon changing
the proton donating acid from HOAc, TFA to HCl, the
interactions between BPP and acid gradually varied from
moderate hydrogen bond, very strong hydrogen bond to
covalent ionic bond in the single crystals. Notably, BPP
molecule showed a variable acid induced luminescence
character based on the different intermolecular interactions
between BPP and acids. Through close investigation on the
crystal structures and corresponding different luminescence
Received: July 18, 2011
Revised: November 20, 2011
Published: December 1, 2011
© 2011 American Chemical Society
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behaviors of BPP−acid, the relationship between supra-
molecular structures and emission properties was discussed.
RESULTS AND DISCUSSION
■
Acid-Induced Luminescence in Solution. BPP was
synthesized according to a literature process,7 and its
luminescence “on” character was first observed in solutions.
In CH2Cl2 solution (5 × 10−5 M), BPP is nonemissive. When
HCl gas was introduced into the BPP solution, strong
luminescence (λem = 399 nm) was achieved immediately
(Figure 1a). The photoluminescence (PL) quantum yield (ΦF)
Figure 2. Absorption spectra of BPP (a) in dilute CH2Cl2 solution (5
× 10−5 M) and (b) in spin-coated film before and after the contact to
HCl, TFA, and HOAc vapor.
Figure 1. (a) The fluorescence spectra and photos of BPP in CH2Cl2
solution (5 × 10−5 M) before and after the bubbling of HCl gas. (b)
The fluorescence photos of spin-coated BPP film before and after the
exposure to HCl, TFA, and HOAc vapor.
π-electron system in the 4-pyrone ring and formation of the
resonance structure of the pyrylium ion in BPP−HCl and
BPP−TFA systems.
X-ray Single Crystal Structure and Emission. To
deeply understand the acid-induced luminescence behavior of
BPP, it is very important to investigate and compare the
molecular and supramolecular structures of BPP, BPP−HCl,
BPP−TFA, and BPP−HOAc systems. By the solvent
evaporation approach, pure BPP and a series of acidified
crystals (BPP−HCl, BPP−TFA, and BPP−HOAc) were
successfully prepared. Their fluorescence images are shown in
the inset of Figure 3, and the normalized emission spectra are
shown in Figure 4. The pure BPP crystal was nonemissive while
the BPP−HCl and BPP−TFA crystals were strongly emissive
and BPP−HOAc crystal displayed weak emission. The solid-
state PL quantum yields (Φf) of the crystals measured by an
integrating sphere were 0.20 for BPP−HCl, 0.23 for BPP−
TFA, and 0.06 for BPP−HOAc, respectively, while that of the
pure BPP crystal grown from neutral THF solution was lower
than 0.01. Different from the nonemissive BPP solution or film
treated with HOAc vapor, the BPP−HOAc crystals obtained
from HOAc-acidified solution exhibited an obviously visible
blue emission with ΦF of 0.06.
of BPP in neutral solution was estimated to be less than 0.01.
While in the solution acidified with HCl, the PL quantum yield
reached 0.24. Other types of acid such as TFA and HOAc were
also employed to check the acid-induced luminescence
property. Upon the introduction of TFA, a similar phenomena
to that occurring in the HCl acidified solution was observed.
TFA could also make BPP solution intensely luminescent (λem
= 405 nm, ΦF = 0.34). However, the addition of HOAc did not
result in the appearance of observable luminescence (ΦF <
0.01) in the BPP solution. Such a prompt and selective
response to acid was also observed in spin-coated BPP thin
films (Figure 1b).
The UV−vis absorption spectra of pure BPP solution and
that treated with different acids were recorded. In dilute
CH2Cl2 solution (5 × 10−5 M) (Figure 2a), BPP has two
absorption peaks at 256 and 282 nm, respectively. In the BPP
CH2Cl2 solutions treated with HCl or TFA gas, the absorption
maxima red-shifted to 345 nm. However, the bubbling of
HOAc vapor did not change the absorption maximum of BPP
CH2Cl2 solution. In the case of thin film, the as-prepared spin-
coated BPP thin film displayed absorption maximum at 305 nm
(Figure 2b). After being exposed to HCl or TFA vapor, the
BPP thin films showed remarkable red-shift of absorption
maximum (352 nm for HCl and 330 nm for TFA). The film
treated with AcOH vapor only showed a very slight red-shift of
absorption maximum (307 nm). The absorption variations
should be attributed to the protonation-induced changes of the
Figure 3b−d presents the contact distances and bond angles
between BPP and acids of HCl, TFA, and HOAc. In BPP−HCl
crystal, the carbonyl group was protonated by the H+ of HCl. In
other words, O1−H1 covalent bond formed. For BPP−HOAc,
a typical hydrogen bonding interaction was adopted between
carbonyl of BPP and hydroxyl of HOAc. However, in BPP−
TFA crystal, it is difficult to precisely judge the bonding type
between BPP and TFA as the contact between the carbonyl of
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Figure 3. The structure and configuration of BPP molecule in (a) neutral, (b) HCl acidified, (c) TFA acidified, and (d) HOAc acidified crystals and
the corresponding crystal fluorescence images (inset).
Scheme 2. Structure of the Pyrylium Ion in BPP−HCl and
BPP−TFA systems
reported diketopyrrolopyrrole compound.9 The distance
between H1 and O1 in BPP−HCl is 1.01 Å, which is a typical
O−H covalent bond value. This result demonstrated that the
carbonyl of BPP has been protonated by HCl. It is worth
noting that after protonation the bond length of C1O1
Figure 4. The normalized fluorescence spectra of neutral BPP, BPP−
HCl, BPP−TFA, and BPP−HOAc crystals.
(carbonyl on BPP) has been elongated to 1.300 Å (1.242 Å in
pure BPP, see Scheme 3). The carbonyl C1O1 has been
BPP and hydroxyl of TFA is in an intermediate state between a
covalent and a strong hydrogen bonding interaction. In BPP−
TFA, the C1−O1−H1 angle (120°) is equal to the value of the
C1−O1−H1 angle (120°) in BPP−HOAc, and the O3−H1−
O1 angle (171°) is located between the values of the Cl1−H1−
O1 angle (178°) in BPP−HCl and the O3−H1−O1 angle
(165°) in BPP−HOAc. In BPP−TFA, the proton H1 contacts
with O1 along the direction of the long pair electron at the O1
atom. Therefore, we believe that the interaction between
carbonyl and hydrogen in BPP−TFA complex has certain
hydrogen bond characteristics. The O1−H1 contact distance of
1.18 Å is very short and is shorter than that of the O1−H3
(1.26 Å). To the best our knowledge, this O1−H1 distance is
one of the shortest reported for O−H hydrogen bonding
system.8 It suggests that the carbonyl group has been partly
protonated by the proton of TFA, and the interaction between
BPP and TFA has exhibited ionic character.
Scheme 3. Bond Lengths in 4-Pyrone Ring under Different
Conditions
In the crystal structure shown in Figure 3b, a H+ ion donated
by a HCl molecule has covalently bonded with the carbonyl
group of the 4-pyrone ring leading to the formation of 4-
hydroxypyrylium ion (Scheme 2), which is similar to the
transformed into the carbon-hydroxyl C1−O1−H1 group in
BPP−HCl. In BPP−TFA crystal as shown in Figure 3c, the
proton donated by TFA was accepted by the O1 of carbonyl in
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BPP; the distance between O1 and H1 is 1.18 Å, which is larger
than that in BPP−HCl, and the carbonyl bond also was
elongated to 1.278 Å. In BPP−TFA the contact distance
between O3 and H1 is 1.26 Å; therefore, the proton nearly
occupied the mild point between O1 and O3. In Figure 3d, the
contact distance between H1 and O1 is 1.68 Å in BPP−HOAc.
Such a distance is just in the range of a moderate hydrogen
bond, indicating the interaction between BPP and AcOH is of a
typical hydrogen bond. The distance between C1 and O1 is
1.253 Å, and this value is slightly longer than that of pure BPP
crystal.
The bond length data of the 4-pyrone ring in different
conditions is illustrated in Scheme 3. In BPP−HOAc the
corresponding C−C, CC, C−O of oxa and CO of
carbonyl bond lengths within the parental 4-pyrone ring
displayed very slight changes compared with pure BPP
molecule. However, in BPP−HCl and BPP−TFA the bond
lengths exhibited remarkable changes. Upon interacting with
HCl or TFA, the shorter bonds (CC and CO of carbonyl)
have been elongated and the longer bonds (C−C and C−O of
oxa) have shortened. In BPP−HCl the parental 4-pyrone ring
structure showed bigger variation compared with BPP−TFA. In
fact, HCl and TFA have induced the formation of the
resonance structure of a pyrylium ion in BPP−HCl and
BPP−TFA systems. The resonance structure should have a
substantial effect on the absorption and emission properties of
the organic π-conjugated systems.
In the four crystals, the phenyl rings display very similar bond
length and angle parameters. For the BPP−HCl and BPP-TFA
crystals that show strong emission, the CO bonds in
carbonyl have been obviously elongated and the structure of the
parental 4-pyrone ring has varied significantly. These
conjugated structure transformations should change the
photophysical properties of the BPP molecule and induce the
light emission, which has been supported by the following
theoretical calculations. For BPP−HOAc crystal that showed
relatively weaker emission, the CO bonds in carbonyl have
been slightly elongated, and the structure of the parental 4-
pyrone ring almost remained unchanged. On the other hand, in
BPP−HOAc two BPP and two HOAc molecules assembled
into a supramolecular structure based on intermolecular
hydrogen bonds (Figure 5), which may enhance the emission.10
According to the single crystal structures shown in Figure 3a−
d, the BPP molecules in all crystals exhibit quite a similar planar
structure feature suggesting that the acid-induced emission and
the red-shifted absorption can not be attributed to the change
of BBP molecular conformation.
Theoretical Calculations. To further confirm the mech-
anism proposed above, theoretical calculations were also carried
out, and the calculated results perfectly agree with the
observations in our experiments. The structures of BPP in
the ground (S0) and the lowest singlet excited (S1) states were
optimized at the B3LYP/6-31G* and CIS/6-31G* level of
theory, respectively. The absorption and emission spectra were
calculated by TD/B3LYP level. All calculations were performed
using the Gaussian 03 program package.11 The results of BPP
in neutral and acidified conditions are listed in Table 1.
Table 1. Selected Absorption and Emission Transition
Wavelengths (nm), Oscillator Strengths (f) and the Main
Contribution of BPP Calculated in a Vacuum
Absorbance
state abs (nm)
f
main contribution
BPP
S1
S3
S8
357
284
247
0.0004
0.3453
0.3726
HOMO → LUMO (86%)
HOMO-2 → LUMO (88%)
HOMO-2 → LUMO + 1 (60%)
HOMO-1 → LUMO (15%)
HOMO → LUMO (87%)
HOMO → LUMO + 1 (45%)
BPP-H+
S1
S7
373
277
0.4282
0.3278
Emission
state em. (nm)
f
main contribution
BPP
BPP-H+
S1
S1
369
390
0.0005
0.4764
LUMO → HOMO (88%)
LUMO → HOMO (85%)
According to these results, the calculated emission of neutral
BPP locates at 369 nm with an oscillator strength of 0.0005. It
means this transition is totally forbidden, consistent with the
nonemissive feature of BPP in neutral solution or thin film.
However, the emission of BPP−H+ complex was calculated to
be at 390 nm with a much stronger oscillator strength of
0.4764, which is consistent with the observed deep blue
emission of BPP in the acidified solution or thin film. It is
worth noting at this stage we cannot give a definite explanation
to the phenomena that BPP−TFA exhibited a slightly high PL
quantum yield (ΦF) compared to BPP−HCl. The Cl− and
F3COO− may have a certain effect on the emission behaviors of
BPP−TFA and BPP−HCl systems.
HCl Responsive Emission Property. Finally, since BPP
exhibited HCl responsive emission on−off switching character,
we have prepared the BPP sample on porous filter paper to
check its cyclic emission response (the emission intensity was
monitored by using a fluorescence microscope connected to a
CCD spectrometer by optical fibers) to HCl and NH3 gas. The
monitored cyclic emission response curve was shown in Figure
6. Clearly, BPP exhibited a typical HCl−NH3 controlled
emission on−off switching feature. Although the peak value of
each cycle dropped gradually due to the focused UV beam
caused fluorescence bleach effect, the profile of this curve
showed that the response was always prompt and totally
reversible after five cycles. It is noteworthy that both HCl and
NH3 gas were directly obtained from their concentrated water
solution without drying or diluting, which indicates the acid
responsive behavior may be stable in such a formidable
Figure 5. The two-BPP and two-HOAc constituted four-molecule
hydrogen bonded planar building blocks in BPP−HOAc crystal. Their
abundant hydrogen bonds may have restricted the molecular rotation
and vibration and decreased the nonemissive process of BPP
molecules.
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BPP was spin-coated into thin film on the quartz plate, and the
emission was monitored by an Olympas BX-51 microscope with
optical fiber connected to the Maya 2000 CCD spectrometer. The
HCl and NH3 gas were directly carried out by constant nitrogen flow
(15 L/min) from their concentrated aqueous solution without drying,
and the export of the gas pipe was fixed at the tested sample.
Crystal Growth, Characterization, and X-ray Crystallogra-
phy. All crystals were obtained by slow solvent evaporation of the
BPP solutions in THF. To obtain the BPP−acid crystals, one drop of
concentrate acid aqueous solution was added into the BPP solutions
(about 10 mL and 10−3 M) in THF, and upon solvent evaporation of
the acidified solution BPP−acid crystals have been obtained. The
fluorescence spectra and images of BPP crystals were taken on the
Olympus BX-51 microscope that connected to a Maya 2000 CCD
optical fiber spectrometer (Ocean Optics). The photoluminescent
quantum yield of the crystals was measured using an AlQ3 film
calibrated integrating sphere (C-701 Opti). The crystal structure data
were collected at 293 K on a Rigaku R-AXIS-RAPID diffractometer
equipped with Mo Kα radiation (λ = 0.71070 Å).
X-ray Crystal Structure Analysis of Pure BPP. A total of 6323
reflections were measured at a maximum 2θ angle of 55.0°, of which
3180 were independent reflections (Rint = 0.0494). The structures
were solved with direct methods and refined with a full-matrix east-
squares technique using the SHELXL-97 programs. All non-hydrogen
atoms were refined anisotropically. The crystal data are as follows:
C136H96O16; FW = 1986.24, crystal size 0.48 × 0.29 × 0.10 mm3,
monoclinic, P2(1)/n, a = 21.836(3) Å, b = 5.6444(7) Å, c = 22.146(3)
Å, α = 90°, β = 109.339°, γ = 90°, V = 2575.5 Å3, Z = 4. The
refinement converged to R1 = 0.0500, wR2 = 0.1659 (I > 2σ(I)), GOF
= 0.944.
Figure 6. The cyclic emission response curve of BPP film exposed to
alternate HCl and NH3 vapor.
environment and immune to humidity disturbance. These
features show that BPP may be a potential candidate for HCl
sensing.
CONCLUSIONS
■
In summary, acid-stimuli-luminescence of BPP and carbonyl-
proton interaction dependent emission properties of BPP,
BPP−HCl, BPP−TFA, and BPP−HOAc crystals were
demonstrated. The acid/base controlled emission on−off
switching character of BPP film was revealed. On the basis of
spectral and X-ray single crystal structure analysis, the acid-
responsive emission of BPP was attributed to the protonation/
strong hydrogen-bonding interaction induced structure change
of the 4-pyrone ring and formation of the resonance structure
of a pyrylium ion in BPP−HCl and BPP−TFA systems. In
BPP−TFA, the interaction between BPP and TFA possesses a
“mixed bond” feature. The interaction between BPP and TFA
displayed partial hydrogen bond and partial ionic bond
characteristics, which may provide a novel and valuable example
for understanding the nature and diversity of the chemical
bonds in supramolecular systems. Since the acid-responsive
luminescence of BPP is mainly based on the interactions
between the carbonyl group of 4-pyrone and the proton of
acids, the introduction of other conjugated or functional
substituents on the pyrone skeleton may produce some novel
materials.
X-ray Crystal Structure Analysis of BPP-HCl. A total of 3806
reflections were measured at a maximum 2θ angle of 55.0°, of which
2607 were independent reflections (Rint = 0.0172). The structures
were solved with direct methods and refined with a full-matrix least-
squares technique using the SHELXL-97 programs. All non-hydrogen
atoms were refined anisotropically. The crystal data are as follows:
C36H30O4Cl6; FW = 739.35, crystal size 0.31 × 0.28 × 0.26 mm3,
triclinic, P1, a = 9.963(4) Å, b = 10.692(4) Å, c = 10.733(7) Å, α =
̅
115.046°, β = 111.896°, γ = 99.061°, V = 890.9 Å3, Z = 2. The
refinement converged to R1 = 0.0588, wR2 = 0.1813 (I > 2σ(I)), GOF
= 1.052.
X-ray Crystal Structure Analysis of BPP−TFA. A total of 3803
reflections were measured at a maximum 2θ angle of 55.0°, of which
2788 were independent reflections (Rint = 0.0316). The structures
were solved with direct methods and refined with a full-matrix east-
squares technique using the SHELXL-97 programs. All non-hydrogen
atoms were refined anisotropically. The crystal data are as follows:
C76H52O16F12; FW = 1449.22, crystal size 0.40 × 0.21 × 0.12 mm3,
monoclinic, P2(1)/n, a = 9.4765(19) Å, b = 9.5705(19) Å, c =
18.723(4) Å, α = 90°, β = 102.69°, γ = 90°, V = 1656.6 Å3, Z = 4. The
refinement converged to R1 = 0.0616, wR2 = 0.2101 (I > 2σ(I)), GOF
= 1.055.
X-ray Crystal Structure Analysis of BPP-HOAc. A total of 3472
reflections were measured at a maximum 2θ angle of 55.0°, of which
1909 were independent reflections (Rint = 0.0490). The structures
were solved with direct methods and refined with a full-matrix east-
squares technique using the SHELXL-97 programs. All non-hydrogen
atoms were refined anisotropically. The crystal data are as follows:
C76H64O16; FW = 1233.33, crystal size 0.55 × 0.40 × 0.10 mm3,
monoclinic, Pc, a = 5.6114(11) Å, b = 10.648(2) Å, c = 26.171(5) Å, α
= 90°, β = 90.14°, γ = 90°, V = 1563.7 Å3, Z = 4. The refinement
converged to R1 = 0.0559, wR2 = 0.1324 (I > 2σ(I)), GOF = 1.004.
EXPERIMENTAL SECTION
■
Material Synthesis and Characterization. The starting materi-
als of methyl benzoate and 1- phenylbutane-1,3-dione were purchased
from Aldrich Chemicals and all solvents used were freshly distilled.
1
The H NMR spectrum of BPP was obtained on the Bruker NMR
spectrometer (500 MHz), and the mass spectra (MS) was measured
on the ITQ 1100 (Thermo Scientific). Element analysis was carried
out on Vario Micro (Elementar). The BPP has been synthesized
according to the reported procedure7 with the starting material of
methyl benzoate and 1-phenylbutane-1,3-dione. BPP sample has been
1
purified by vacuum sublimation. H NMR (500 MHz, CDCl3, TMS,
δ): 7.85−7.92 (m, 4H), 7.52−7.58 (m, 6H), 6.89 (s, 2H). MS (EI, m/
z): calcd. for C17H12O2, 248.28; found, 247.98. Elementary analysis
calcd. for C17H12O2 (248.25): C 82.24, H 4.87; found: C 82.76, H
4.72.
Emission, Absorption and the Cyclic Emission on−off
Switcher Measurements. The emission spectra of BPP in dichloro-
methane solutions was measured on a PE LS-55 fluorescence
spectrometer, while the emission spectra of BPP spin-coated film
was measured by a Maya 2000 CCD optical fiber spectrometer (Ocean
Optics). The absorption measurement of all samples was carried out
on UV-2550 (SHIMAZU). The cyclic emission on−off switcher test:
ASSOCIATED CONTENT
■
S
* Supporting Information
Crystallographic data for neutral BPP, BPP−HCl, BPP−TFA,
and BPP−HOAc in CIF formats. This information is available
free of charge via the Internet at http://pubs.acs.org.
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J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.;
Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.;
Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.;
Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen,
W.; Wong, M. W.; Gonzalez, C. Pople, J. A. Gaussian 03, Revision
C.02; Gaussian, Inc.: Pittsburgh, PA, 2003.
AUTHOR INFORMATION
■
Corresponding Author
*E-mail: hongyuzhang@jlu.edu.cn (H.Z.); yuewang@jlu.edu.cn
(Y.W.).
ACKNOWLEDGMENTS
■
This work was supported by the National Natural Science
Foundation of China (50773027, 20921003, and 51173067),
the Major State Basic Research Development Program
(2009CB939700), and 111 Project (B06009).
REFERENCES
■
(1) (a) Wakamiya, A.; Inukai, Y.; Yamaguchi, S. J. Am. Chem. Soc.
2006, 128, 15934. (b) Iida, A.; Yamaguchi, S. Chem. Commun. 2009,
3002. (c) An, B. K.; Gihm, S. H.; Chung, J. W.; Park, C. R.; Kwon, S.
K.; Park, S. Y. J. Am. Chem. Soc. 2009, 131, 3950. (d) Yuan, W. Z.; Lu,
P.; Chen, S. M.; Lam, J. W. Y.; Wang, Z. M.; Liu, Y.; Kwon, H. S.; Ma,
Y. G.; Tang, B. Z. Adv. Mater. 2010, 22, 2159.
(2) (a) Wang, L.; Jiang, Y.; Luo, J.; Zhou, Y.; Zhou, J. H.; Wang, J.;
Pei, J.; Cao, Y. Adv. Mater. 2009, 21, 4854. (b) Gong, S. L.; Chen, Y.
H.; Yang, C. L.; Zhong, C.; Qin, J. G.; Ma, D. G. Adv. Mater. 2010, 22,
5370. (c) Wang, R. J.; Liu, D.; Ren, H. C.; Zhang, T.; Yin, H. M.; Liu,
G. Y.; Li, J. Y. Adv. Mater. 2011, 23, 2823.
(3) (a) Lim, S. H.; Olmstead, M. M.; Balch, A. L. J. Am. Chem. Soc.
2011, 133, 10229. (b) Maeda, H.; Bando, Y.; Shimomura, K.; Yamada,
I.; Naito, M.; Nobusawa, K.; Tsumatori, H.; Kawai, T. J. Am. Chem.
Soc. 2011, 133, 9266. (c) Tong, X.; Zhao, Y.; An, B. K.; Park, S. Y. Adv.
Funct. Mater. 2006, 16, 1799. (d) Li, C. H.; Zhang, Y. X.; Hu, J. M.;
Cheng, J. J.; Liu, S. Y. Angew. Chem., Int. Ed. 2010, 49, 5120.
(4) (a) Ryu, S.; Yoo, I.; Song, S.; Yoon, B.; Kim, J. M. J. Am. Chem.
Soc. 2009, 131, 3800. (b) Hu, R.; Feng, J.; Hu, D. H.; Wang, S. Q.; Li,
S. Y.; Li, Y.; Yang, G. Q. Angew. Chem., Int. Ed. 2010, 49, 4915.
(c) Maffei, F.; Betti, P.; Genovese, D.; Montalti, M.; Prodi, L.; Zorzi,
R. D.; Geremia, S.; Dalcanale, E. Angew. Chem., Int. Ed. 2011, 50, 4654.
(5) (a) Piao, X. J.; Zou, Y.; Wu, J. C.; Li, C. Y.; Yi, T. Org. Lett. 2009,
11, 3818. (b) Dertinger, T.; Heilemann, M.; Vogel, R.; Sauer, M.;
Weiss, S. Angew. Chem., Int. Ed. 2010, 49, 9441.
(6) (a) Fan, Y.; Zhao, Y.; Ye, L.; Li, B.; Yang, G.; Wang, Y. Cryst.
Growth Des. 2009, 9, 1421. (b) Xie, Z.; Wang, H.; Li, F.; Xie, W.; Liu,
L.; Yang, B.; Ye, L.; Ma, Y. Cryst. Growth Des. 2007, 7, 2512. (c) Xie,
Z.; Liu, L.; Yang, B.; Yang, G.; Ye, L.; Li, M.; Ma, Y. Cryst. Growth Des.
2005, 5, 1959. (d) Zhang, Z. L.; Zhang, Y.; Yao, D. D.; Hai, B.; Javed,
I.; Fan, Y.; Zhang, H. Y.; Wang, Y. Cryst. Growth Des. 2009, 9, 5069.
(e) Zhou, T. L.; Li, F.; Fan, Y.; Song, W. F.; Mu, X. Y.; Zhang, H. Y.;
Wang, Y. Chem. Commun. 2009, 3199.
(7) Yao, Y. S.; Xiao, J.; Wang, X. S.; Deng, Z. B.; Zhang, B. W. Adv.
Funct. Mater. 2006, 16, 709.
(8) (a) Jeffrey, G. A. An Introduction to Hydrogen Bonding; Oxford
University Press: Oxford, 1997. (b) Fabien, F. V.; Mark, R. J.; Gordon,
J. K.; Judith, A. K. H.; Stewart, F. P. J. Am. Chem. Soc. 2006, 128, 2963.
(c) Yitbarek, H. M.; Ryza, N. M. J. Phys. Chem. A 2008, 112, 134.
(9) Yamagata, T.; Kuwabara, J.; Kanbara, T. Tetrahedron Lett. 2010,
51, 1596.
(10) Zhou, T. L.; Li, F.; Fan, Y.; Song, W. F.; Mu, X. Y.; Zhang, H.
Y.; Wang, Y. Chem. Commun. 2009, 199.
(11) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.;
Robb, M. A.; Cheeseman, J. R.; Montgomery, J. A., Jr.; Vreven, T.;
Kudin, K. N.; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.;
Barone, V.; Mennucci, B.; Cossi, M.; Scalmani, G.; Rega, N.;
Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.;
Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao,
O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J.
B.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev,
O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.;
Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.;
Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.;
Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman,
184
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