DOI: 10.1002/asia.201402094
Synthesis and Characterization of Two-Photon Chromophores Based on a
Tetrasubstituted Tetraethynylethylene Scaffold
Tzu-Chau Lin,*
[a]Yi-You Liu,
[a]May-Hui Li,
[a]Che-Yu Liu,
[a]Sheng-Yang Tseng,
[b]Yu-Ting Wang,
[b]Ya-Hsin Tseng,
[b]Hui-Hsin Chu,
[b]and Chih-Wei Luo
[b]Introduction
The intrinsic quadratic dependence of two-photon
absorp-tion (2PA) on incident light intensity is one of the major
characters that makes this third-order nonlinear optical
phe-nomenon applicable in many photonics and biophotonics
applications such as optical power limiting, frequency
up-converted lasing, 3D optical data storage, 3D
microfabrica-tion, nondestructive bioimaging, and two-photon
photody-namic therapy.
[1]For the development of two-photon
tech-nologies, the exploration of new materials with strong 2PA
plays an equally important role as the advancement of high
peak-power pulsed lasers. Through rational molecular
design, it is possible to synthesize organic chromophores
that exhibit several orders of intensified 2PA with other
de-sired molecular characteristics simultaneously integrated,
which helpfully compensates the relatively poor
perfor-mance of commercialized dyes for the aforementioned
ap-plications based on 2PA. So far, it has been realized that the
combination of several structural parameters such as
intra-molecular charge-transfer efficiency, effective size of the
p-conjugation domain, and the structural dimensionality of
a molecule are closely related to molecular 2PA.
[2–10]This
also means that the arrangement of the selected building
units within a molecule plays a pivotal role in molecular
design towards highly active 2PA chromophores. Following
our continuous efforts in the search of effective structural
parameters for the enhancement of molecular 2PA in
multi-branched dye systems possessing heterocyclic ring
com-plexes, in this paper we present the synthesis of new
multi-polar two-photon-active model chromophores based on the
tetrasubstituted tetraethynylethylene (TEE) skeleton by
using functionalized quinoxaline, indenoquinoxaline, and
pyridopyrazine moieties as the substituents. We also report
initial investigations into their nonlinear optical properties
in both the femtosecond and nanosecond time domains.
Results
Model chromophores and synthesis
The chemical structures and the synthetic routes to the
stud-ied model compounds are illustrated in Figure 1 and
Scheme 1, respectively. The compound set contained three
multibranched analogues, the molecular structures of which
were constructed by attaching four identical
functionalized-quinoxalinoid lobes to a common central ethylene core
through CC bonds. Alternatively, the central part of these
model compounds can be viewed as a TEE moiety, which is
an attractive building unit for the construction of various
p-conjugated carbon-rich structures that exhibit c
3nonlineari-ties and photochromic propernonlineari-ties.
[11]Therefore, we believed
that the 2PA-related properties of chromophores with an
in-corporated TEE skeleton deserved to be explored. In this
work we tentatively introduced the TEE unit as the
connec-tion center and constructed a multipolar model
chromo-Abstract: A new series of model dye
molecules composed of three
multi-branched analogues based on the
tetra-substituted tetraethynylethylene
struc-tural motif have been synthesized and
experimentally shown to possess strong
and widely dispersed two-photon
ab-sorption (2PA) in the near-IR region.
It was found that the spectral position
of the major 2PA band could be tuned
by the electronic nature of the selected
substitution units. The studied model
fluorophores also exhibited fairly low
photodegradation of their fluorescence
intensity even under prolonged
UV-light irradiation, which is beneficial for
the
development
of
fluorescence
probes that are needed for long-term
light exposure. Furthermore,
represen-tative chromophores were selected to
demonstrate the power-control
proper-ties within the femtosecond and
nano-second time domains.
Keywords: absorption
·
chromo-phores · heterocycles · nonlinear
optics · Sonogashira reaction
[a] Prof. T.-C. Lin, Y.-Y. Liu, M.-H. Li, C.-Y. Liu Photonic Materials Research Laboratory Department of Chemistry
National Central University
300 Jong-da Rd. 32001 Jhong-Li (Taiwan) Fax: (+ 886) 3-4227664
E-mail: [email protected]
[b] S.-Y. Tseng, Y.-T. Wang, Y.-H. Tseng, H.-H. Chu, Prof. C.-W. Luo Department of Electrophysics
National Chiao-Tung University Hsinchu (Taiwan)
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/asia.201402094.
phore system based on the tetrasubstituted TEE motif for
the investigation of the 2PA-related properties. We selected
quinoxalinoids as the major aryl substituents, as they were
recently found to be useful structural units for building
highly active 2PA dyes.
[10c–e, 12]The model compounds were
synthesized in acceptable yields by coupling terminal
al-kynes 10–12 with tetraiodoethylene under Sonogashira
con-ditions, as illustrated in Scheme 1. The aforementioned
ter-minal alkynes were obtained through consecutive
function-alization starting from 4–6, and the details of the syntheses
of the precursors and targeted model compounds are
de-scribed in the Experimental Section.
Linear and nonlinear optical properties
Linear absorption and fluorescence properties
Figure 2 illustrates the linear absorption and fluorescence
spectra of the studied dye molecules in the solution phase
by using toluene as the solvent. The studied model
chromo-phores displayed intense one-photon absorption (1PA) in
the 300–470 nm range, and the lowest-energy absorption
bands were located at 441 (e
1.63 10
5), 447 (e
2.76 10
5),
and 470 nm (e
1.17 10
5cm
1m
1) for 1, 2, and 3,
respec-tively. Solutions of these compounds also emitted intense
fluorescence under irradiation of a common UV lamp with
blue-greenish color for 1 and 2 and yellow-orange color for
3, which is in agreement with the measured emission spectra
(see Figure 2 b).
Despite the symmetrical nature of their molecular
struc-tures, the fluorescence properties of all these model
chromo-phores possessed strong solvent effects, including band
posi-tions and lifetimes as shown in Figure 3 by using
chromo-phore 2 as a representative for this behavior. Similar
behav-ior has been observed for other multipolar chromophore
systems, and it is postulated that symmetry breaking owing
to electron-vibration coupling and dipolar solvation effects
are the major causes for this phenomenon.
[13, 14]The
mea-sured photophysical properties of these model
chromo-phores are collected in Table 1.
The photostability of the studied dye compounds in the
solution phase (1 10
6m
in toluene) was tentatively
evaluat-ed by continuously monitoring the decay of their
fluores-cence intensity over the course of UV irradiation. We
uti-lized a set of UV lamps as the excitation light source to
pro-vide approximately 350 nm radiation with a total output of
64 W for this experiment. The detailed experimental
ar-rangement is described in the Supporting Information. As
il-lustrated in Figure 4, during the first 1 h of consecutive
ex-posure to UV light, all of the model compounds retain
95 % of their original emission intensity. Prolonged
irradi-ation further deteriorated the emissive properties of these
model chromophore solutions. Compound 3 showed a larger
fluorescence intensity drop (
22 %), whereas this intensity
drop was kept within approximately 9 % for 1 and 2 after
exposure to UV light for 3 h. Overall, model compounds
1 and 2 showed fairly good resistance to photodamage, and
their resistance was superior to that of compound 3 under
our experimental condition. We highly suspect that the
weak photoresistance of 3 may originate from the pyridine
unit in the ring complex, but clarification of this issue is
cur-rently beyond the scope of this work.
Two-photon-excited fluorescence properties
The studied model chromophores exhibited strong
two-photon-excited fluorescence emission even under irradiation
of an unfocused femtosecond laser beam at approximately
800 nm at a low-intensity level. Figure 5 illustrates the
2PA-induced fluorescence properties of the studied dye
com-pounds measured by the two-photon-excited fluorescence
(2PEF) technique. A wavelength-tunable mode-locked
Ti:-sapphire laser (Chameleon Ultra II, Coherent) that
deliv-ered approximately 140 fs pulses at a repetition rate of
80 MHz and a beam diameter of 2 mm was utilized as the
excitation light source for these experiments. The intensity
level of the excitation beam was carefully regulated to avoid
absorption and photodegradation saturation of the samples
during the course of the experiments. Furthermore, the
rela-tive position of the excitation beam was adjusted to be as
close as possible to the wall of the quartz cell (10 10 mm
cuvette) so that only the emission from the front surface of
Scheme 1. Synthetic procedures for the target model chromophores.Figure 2. Linear absorption spectra (a) and fluorescence spectra (b) of 1– 3 in the solution phase (1 10 6min toluene).
Figure 3. Fluorescence spectra of 2 in various solvents (concentration = 1 10 6mfor all cases). The measured fluorescence lifetime (t
1PA-FL) of 2
the sample was recorded. Figure 5 a illustrates the
normal-ized 2PA-induced fluorescence spectra of 1–3 in the solution
phase. The quadratic dependence of the fluorescence
inten-sity on the excitation light inteninten-sity of these model
com-pounds as shown in Figure 5 b–d validates that 2PA is the
major process that causes the observed up-converted
emis-sion.
Two-photon absorption spectra
measurement
The dispersion of the 2PA
be-havior of these model molecules
as a function of wavelength was
probed in the near-IR regime
(680–1000 nm)
by
the
2PEF
method by using fluorescein (
80 mm in pH 11 NaOH
solu-tion)
as
the
standard.
[15, 16]Figure 6 shows the measured
degenerate two-photon
absorp-tion spectra of these model
compounds in toluene. From
this figure one can see that all
of these model compounds
ex-hibited strong 2PA ( 500 GM) within the major dynamic
tuning range of a Ti:sapphire oscillator (i.e., 680–950 nm),
which implies that the current structural combination based
on attaching four electron-donor-functionalized
quinoxali-noids to a central TEE core is a useful approach toward
strong 2PA dyes. To be more specific with regard to the 2PA
spectral distribution of the studied model chromophores,
compound 1 exhibited a broad 2PA band with two local
maxima located at approximately 740 (d
24280 GM) and
840 nm (d
23920 GM), whereas compound 2 possessed
a nearly identical 2PA dispersion pattern but with greatly
elevated cross-section values, particularly at approximately
750 nm (d
28030 GM), in comparison to 1, which indicates
that the replacement of the quinoxaline unit by an
indeno-Table 1. Photophysical properties of model chromophores 1–3 in toluene.[a]Chromophore labs max[nm]
[b] log e[c] lem max[nm]
[d] F
F[e] t2PA-FL[ns][f] dmax2 [GM] [g] F Fdmax2 [GM] [h] 1 302 365 441 5.28 5.31 5.21 521 0.69 2.4 4280 (at 740 nm) 2950 2 306 361 447 5.34 5.39 5.44 496 0.66 1.5 (in toluene) 4.2 ACHTUNGTRENNUNG(in THF) 5.4 ACHTUNGTRENNUNG(in CH2Cl) 8030 (at 750 nm) 5300 3 300 368 470 5.22 5.26 5.07 576 0.66 3.7 4000 (at 930 nm) 2640
[a] Concentration was 1 106 and 1 10 4m for 1PA-related and 2PA-related measurements, respectively.
[b] One-photon absorption maximum. [c] Molar absorption coefficient of the corresponding absorption band. [d] 1PA-induced fluorescence emission maximum. [e] Fluorescence quantum efficiency. [f] 2PA-induced fluo-rescence lifetime. [g] Maximum 2PA cross-section value (with experimental error 15 %); 1 GM = 1 1050cm4s (photon-molecule) 1. [h] Two-photon action cross-section value.
Figure 4. Evaluation of the photostability: Fluorescence spectra of the studied chromophores in the solution phase under consecutive irradiation of UV light at 350 nm (insets: fluorescence intensity change over the course of UV-light exposure).
Figure 5. a) Two-photon-excited fluorescence spectra of the studied model chromophores; b–d) logarithmic plots of power-squared depend-ence of the 2PA-induced fluorescdepend-ence intensity on the input intensity of these compounds in toluene.
quinoxaline moiety in this dye system had a positive effect
on the promotion of molecular 2PA, especially at shorter
wavelengths. This feature could become very desirable if
large two-photon absorptivity within a specific spectral
region is needed for particular applications. Compound 3
also showed widely dispersed 2PA and a bathochromically
shifted
local
maximum
at
approximately
930 nm
(d
24000 GM) compared to compound 1.
Discussion of the results
From the measured photophysical properties of the studied
model chromophores in the present work, the following
fea-tures can be seen:
1) On the basis of the measured linear absorption spectra
of the studied model chromophores by using compound
1 as a reference, compound 2 exhibited a distinct
in-crease in the linear absorption with nearly identical
spectral dispersion relative to compound 1, whereas
compound 3 showed relatively smaller linear absorption
and a redshifted lowest-energy band. These features
in-dicate that the involvement of a fluorene unit as part of
the heterocyclic ring complex in this molecular system
(as in the case of 2) is an effective approach to enhance
linear absorptivity without shifting the position of the
absorption band, whereas utilization of a pyridine
moiety for the construction of a heterocyclic ring
com-plex (as in the case of 3) is useful for expanding the
spectral range of linear absorption by moving the
lowest-energy band bathochromically.
(2) Originally, we suspected that the TEE unit utilized as
a ramification center in this model chromophore system
could be photosensitive and consequently weaken the
photoresistance of these compounds because of the
eth-ynyl components in each structure; nevertheless, the
ex-perimental results revealed that this functional group is
fairly inert toward UV radiation at approximately
350 nm. Among these three model compounds, 1 and 2
exhibited good photostability, which implies that the
structural units employed in these two compounds are
suitable for the development of robust fluorescence
probes that are needed for prolonged UV-light
expo-sure. We are also aware that the results from the current
photostability test may not fully represent the
photore-sistant character of these model compounds in other
spectral regions, especially within their
two-photon-active regime. Therefore, in addition to the presented
work, a more comprehensive evaluation on the
photo-stability of the studied chromophores under the
expo-sure of near-IR radiation is needed, and such an
experi-ment is one of the major subjects of our future work.
(3) Relative to the 2PA of compound 1, the noticeably
hy-perchromic 2PA of 2 in the shorter wavelength region
and the distinctly redshifted 2PA of 3 indicate that
fluo-rene can be an effective structural unit to enhance
mo-lecular 2PA with a roughly immobilized spectral position
of the 2PA band, whereas the pyridine scaffold can
effi-ciently redshift the 2PA and retain the same level of
2PA. These features are particularly useful for
molecu-lar design if either molecu-large 2PA at a specific spectral range
or a redshifted 2PA band with a fixed cross-section level
is required for different applications.
(4) Recent theoretical studies on certain organic structures
revealed that molecular 2PA is correlated to the square
of the effective p-electron number.
[17]Although this
ap-proximation rule has not been verified yet to be totally
suitable for various classes of conjugated molecules with
different geometries, this scaling may serve as a
refer-ence for the tentative and qualitative analysis of our
ex-perimental results. From the viewpoint of molecular
structure, the major difference between these model
compounds is the heterocyclic part of each
chromo-phore, and if it is assumed that the p-electrons on each
model dye compound follow the same mode of
contri-bution to the nonlinear response, the one with a ring
complex that provides a larger number of p-electrons
can be expected to exhibit a higher maximum molecular
2PA. Therefore, compound 2 can be expected to show
the highest maximum molecular 2PA among the studied
model compounds, as its indenoquinoxaline units
pro-vide the largest number of p-electrons compared to the
p-electron numbers offered by the quinoxalines and
pyr-idopyrazines on compounds 1 and 3, respectively. In
par-allel, the maximum molecular 2PA cross-section values
of compounds 1 and 3 can be expected to be at the
same level, because the heterocyclic ring complex parts
of these two compounds possess the same numbers of
p-electrons.
(5) Combining the medium-high fluorescence quantum
yields and the 2PA cross-section values, chromophores
1–3 exhibit comparable maximum two-photon action
cross-sections (F
Fd
max
2
, F
Fis fluorescence quantum
yiel-d),
[1a–c, 2a]and this property suggests that such a structural
motif could be useful to build an efficient frequency
up-converter for imaging-related applications such as
two-photon-excited fluorescence microscopy. Additionally,
Figure 6. Measured degenerate two-photon absorption spectra of modelchromophores 1–3 by the 2PEF method in toluene solution at 1 104
m (experimental error 15 %).
from the viewpoint of practical applications, it might be
interesting to explore the photophysical properties of
these model compounds in the solid state (e.g., in film
configuration) and such work is currently being
ex-plored.
Optical power-limiting and stabilization properties in
various time domains
Ideally, an optical limiter is expected to show spectrally
broad and temporally agile response to incident laser light.
Various nonlinear optical mechanisms have been employed
to achieve optical limiting, and among them, 2PA is
theoret-ically considered as a potential process to approach the
aforementioned ideal characteristics for optical control. The
quadratic dependence of 2PA on the input light intensity
has made 2PA materials applicable in optical-limiting
appli-cations, because such materials are transparent to the
inci-dent light at low intensity but become opaque if the input
intensity is increased. Given that this optical-control
func-tion stems from the intrinsic physical properties of the
mate-rial, no external sensing or control mechanism is required to
accomplish such optical suppression so that the response
speed of a 2PA-based optical limiter can be very fast and
the structure of the device can be very simple.
To demonstrate the 2PA-based power-limiting
perfor-mance of the studied fluorophores, we selected compound 2
as a representative and utilized femtosecond laser pulses
from a regenerative amplifier to probe its optical
power-lim-iting properties at approximately 800 nm. The sample
solu-tion for this study was prepared in toluene with a
concentra-tion of 0.02 m, and the experimental setup for this
measure-ment is described in detail in the Supporting Information.
Figure 7 illustrates the measured data for the dependence of
the output power on the input power of the probing laser
beam. In this figure, the measured transmitted intensity data
are presented by solid hexagons, and the dark-gray solid line
is the theoretical curve, with the best fitting parameter of
b = 2.25 cm GW
1. For comparison, the diagonal dotted line
shows the behavior of a medium without nonlinear
absorp-tion, and one can see that the measured input–output curve
starts to deviate from the linear transmission (diagonal
dotted line) at low pumping power and rapidly approaches
larger values of this deviation as the excitation power levels
up. Moreover, the 2PA cross-section value of this model
compound was calculated to be approximately 3100 GM
from the performed optical-power-limiting experiment,
which is very close to the result obtained from the 2PEF
method within experimental uncertainty. This validates that
2PA should be the major cause for the observed
up-convert-ed emission and optical-power restriction in this
chromo-phore system.
It has been reported that two-photon-active materials
may also exhibit two-photon-assisted excited-state
absorp-tion (2PA-assisted ESA) under the irradiaabsorp-tion of
nanosec-ond or longer laser pulses, especially if the excited-state
life-time of the studied material is on the same life-time regime with
the duration of the laser pulse.
[18]Such behavior will lead to
larger apparent nonlinear attenuation of the incident light
and consequently to better optical-control performance.
From the viewpoint of fundamental research, it is important
to gain knowledge of the connection between molecular
structure and the 2PA-induced excited-state dynamics to
es-tablish a clear guideline for molecular design to precisely
fulfill various requests of different applications. So far, only
very limited experimental and theoretical attempts have
been conducted to study 2PA-assisted ESA on the basis of
organic dyes;
[18, 19]therefore, the dependence of excited-state
behavior on molecular structure is still lacking. Nevertheless,
from the standpoint of applications, any medium that
pos-sesses large apparent nonlinear absorption over a wide
spec-tral range could be very useful for effective optical-power
attenuators against long laser pulses.
[20]These optical-power
attenuation properties can also be utilized to suppress the
power or energy fluctuation of laser pulses, which is very
de-sirable for many laser-based applications such as optical
tel-ecommunication, optical fabrication, and optical data
proc-essing. To tentatively test the effective
optical-power-stabili-zation properties against long laser pulses on the basis of
these model compounds, chromophores 2 and 3 were
select-ed for this experiment. Furthermore, given that the maxima
2PA of 2 and 3 are located at approximately 750 and 930 nm
(see Figure 6), these two wavelengths were utilized for this
test, because a higher 2PA-induced excited-state population
could be reached and, consequently, larger apparent
nonlin-ear absorption and better power-stabilization performance
was expected. As an excitation light source, a tunable
nano-second laser system (an integrated Q-switched Nd:YAG
laser and OPO: NT 342/3 from Ekspla) was employed to
generate 6 ns laser pulses with controlled average pulse
energy in the range from approximately 0.02 to 2 mJ with
a repetition rate of 10 Hz for this investigation. The
experi-mental results for the optical-stabilization study on the basis
Figure 7. Measured output energy versus input energy of femtosecond laser pulses at 800 nm based on a 1 cm path solution sample of 2 in tolu-ene at 0.02 m. The solid curve is the theoretical data with best-fit parame-ter of b = 2.25 cm GW1.of these two sample solutions are shown in Figure 8. The
curves in Figure 8 a, c are the instantaneous pulse-energy
changes in the incident laser beam at the corresponding
wavelengths. The input pulses possess a relatively large
energy fluctuation, as shown in Figure 8 a, c, and after
pass-ing through solutions of 2 and 3, reduced fluctuation of the
pulse energy was observed for the output signals for each
case, as illustrated in Figure 8 b, d. For the purpose of
com-parison, the average levels of both the input and output
sig-nals were normalized to the same value, and from the
mea-sured data, compound 2 is a better optical-power stabilizer
than compound 3.
It should be reiterated that the individual contributions
originating from intrinsic 2PA and possible ESA to the
ob-served optical-energy attenuation of the tested chromophore
systems is indistinguishable under the current experimental
conditions. Therefore, the results presented herein could be
assumed as a combined effect based on the aforementioned
nonlinear processes.
Conclusions
In conclusion, we synthesized a novel multipolar
chromo-phore set composed of three congeners on the basis of the
tetrasubstituted tetraethynylethylene structural motif by
using functionalized quinoxalinoids as the main aryl
sub-stituents. The initial experimental results showed that these
model fluorophores display widely dispersed and strong
two-photon absorption in the near-IR region. Tentative
structure–2PA properties analysis revealed that integration
of a fluorene unit as part of the heterocyclic ring complex
was a useful strategy to promote molecular 2PA, particularly
at short wavelengths, whereas the incorporation of a pyridine
moiety as a component of the heterocycles was beneficial in
shifting the 2PA band bathochromically without a huge
de-cline in the maximum 2PA. Moreover, model chromophore
2 was demonstrated to exhibit intrinsic 2PA-based
optical-power-limiting properties against femtosecond laser pulses.
In addition, both 2 and 3 were selected to test their
optical-power stabilization properties against long laser pulses at
wavelength positions for which these two model
chromo-phores exhibit maximum 2PA, and as expected, fairly good
power-stabilization performance of these two compounds
was observed. Combining the good photostability and strong
two-photon action cross-section (F
Fd
max
2
), these model
chro-mophores could be potential prototypes for the
develop-ment of 2PA-based fluorescence probes for long-term light
exposure.
Experimental Section
General
All commercially available reagents for the preparation of the intermedi-ates and targeted chromophores were purchased from Acros Organics or Alfa Aesar and were used as received, unless stated otherwise.1H NMR
and13C NMR spectra were recorded with a 300 MHz spectrometer and
referenced to tetramethylsilane or residual CHCl3. The representative
numbering of carbon and hydrogen atoms on each intermediate and model chromophore for the assignment of the NMR signals was system-atized and is illustrated in the Supporting Information. HRMS was con-ducted by using a Waters LCT ESI-TOF mass spectrometer. MALDI-TOF MS spectra were obtained with a Voyager DE-PRO mass spectrom-eter (Applied Biosystem, Houston, USA).
Photophysical methods
All of the linear optical properties of the subject model compound were measured by the corresponding spectrometers. Detailed experimental conditions as well as the optical setups for nonlinear optical properties investigations are described in the Supporting Information.
Synthesis
In Scheme 1, compounds 4–6 were the major starting materials for the synthesis of each intermediate and model chromophore. These three compounds were obtained by following established procedures.[10c]For
the synthesis of other key intermediates (i.e., compounds 7–9 and 10–12) and targeted model compounds 1–3, a series of functionalization steps starting from compounds 4–6 were conducted and are presented below. 7,7’-{6-[(Trimethylsilyl)ethynyl]quinoxaline-2,3-diyl}bis(9,9-dihexyl-N,N-diphenyl-9H-fluoren-2-amine) (7): PdCl2ACHTUNGTRENNUNG(PPh3)2 (0.052 g, 0.074 mmol),
CuI (0.023 g, 0.12 mmol), trimethylsilyl acetylene (0.18 g, 1.86 mmol), and iPr2NH (2.5 mL) were added to a mixture of 4 (1.5 g, 1.24 mmol) in
dry THF (10 mL). The resulting solution was stirred at 90 8C under an Ar atmosphere for 21 h. After cooling to room temperature, H2O (
100 mL) was added to the reaction mixture. The above solution was then extracted with CH2Cl2(3 30 mL), and the organic layer was
col-lected and dried with MgSO4(s). After removing the solvent, the crude
product was purified by column chromatography on silica gel (THF/ hexane = 1:10) to give the final purified product as a yellow powder (1.4 g, 92.1 %).1H NMR (300 MHz, CDCl 3): d = 8.31 (s, 1 H; H-F), 8.10– 8.07 (d, J = 8.4 Hz, 1 H; H-C), 7.78–7.76 (d, J = 8.4 Hz, 1 H; H-B), 7.75– 7.50 (m, 8 H; H-9, H-12, H-13, H-15), 7.26–7.21 (m, 8 H; H-2), 7.12–7.00 (m, 10 H; 3, 6), 7.00–6.96 (m, 6 H; 1, 8), 1.75–1.72 (m, 8 H; H-f), 1.12–0.94 (m, 24 H; H-c, H-d, H-e), 0.94–0.74 (m, 12 H; H-a), 0.64 (s, 8 H; H-b), 0.31 ppm (s, 9 H; methyl hydrogen atoms of the TMS group); Figure 8. a, c) Measured instantaneous pulse energy fluctuation of the
input laser pulses at 750 and ~ 930 nm; b, d) measured instantaneous pulse energy fluctuation of the output laser pulses at corresponding wavelengths after passing through solutions of 2 and 3. The repetition rate of the laser pulse was 10 Hz, and the average input pulse energy level was approximately 1 mJ.
13C NMR (75 MHz, CDCl
3, tentative assignments based on calculated
values): d = 154.62 (C-H), 154.22 (C-G), 152.61 (C-16), 150.59 (C-5), 150.51 (C-D), 147.87 (C-4), 147.50 (C-E), 141.80 (C-11), 140.80 (C-7), 140.70 (C-A), 137.05 (C-14), 135.39 (C-10), 132.67 (C-F), 132.54 (C-B), 129.13 2), 128.98 12, C-C-), 124.34 15), 123.86 3), 123.34 (C-13), 122.55 (C-1), 120.86 (C-8), 118.91 (C-9), 118.82 (C-6), 104.39 (acety-lene carbon), 97.12 (acety(acety-lene carbon), 55.05 g), 40.09 f), 31.53 (C-e), 29.56 (C-d), 23.82 (C-c), 22.59 (C-b), 14.06 (C-a), 0.11 ppm (methyl carbon atoms of the TMS group); HRMS (MALDI-TOF): m/z: calcd for C87H96N4Si: 1224.7405 [M]
+; found: 1224.7440.
7,7’-{10,10-Dihexyl-8-[(trimethylsilyl)ethynyl]-10H-indenoACHTUNGTRENNUNG[1,2-g]quinoxa-line-2,3-diyl}bis(9,9-dihexyl-N,N-diphenyl-9H-fluoren-2-amine) (8): PdCl2
ACHTUNGTRENNUNG(PPh3)2(0.074 g, 0.10 mmol), CuI (0.03 g, 0.18 mmol), trimethylsilyl
acety-lene (0.29 g, 2.96 mmol), and iPr2NH (3 mL) were added to a mixture of
5 (2.58 g, 1.76 mmol) in dry THF (10 mL). The resulting solution was stirred at 90 8C under an Ar atmosphere for 17 h. After cooling to room temperature, H2O ( 100 mL) was added to the reaction mixture. The
above solution was then extracted with CH2Cl2(3 30 mL), and the
or-ganic layer was collected and dried with MgSO4(s). After removing the
solvent, the crude product was purified by column chromatography on silica gel (THF/hexane = 1:10) to give the final purified product as an orange powder (2.4 g, 92 %). 1H NMR (300 MHz, CDCl 3): d = 8.41 (s, 1 H; H-H), 8.07 (s, 1 H; H-K), 7.86–7.82 (d, J = 7.8 Hz, 1 H; H-D), 7.62– 7.58 (m, 10 H; 9, 12, 13, 15, B, E), 7.27–7.21 (m, 8 H; H-2), 7.12–7.07 (m, 10 H; H-3, H-6), 7.04–6.98 (m, 6 H; H-1, H-8), 2.19–2.01 (m, 4 H; f’), 1.77–1.70 (m, 8 H; f), 1.21–0.88 (m, 36 H; c, c’, H-d, H-d’, H-e, H-e’), 0.81–0.63 (m, 30 H; H-a, H-a’, H-b, H-b’), 0.31 ppm (s, 9 H; methyl hydrogen atoms of the TMS group);13C NMR (75 MHz,
CDCl3, tentative assignments based on calculated values): d = 153.46
16), 153.03 N), 152.58 5), 151.24 M), 150.57 A), 150.48 (C-L), 147.89 (C-4), 147.40 (C-F), 143.15 (C-J), 141.52 (C-I), 141.36 (C-G), 141.19 (C-11), 140.06 (C-7), 137.52 (C-14), 137.44 (C-14’), 135.54 (C-10), 131.55 (C-B), 129.12 (C-2, C-12, C-E), 126.52 (C-D), 124.37 (C-15), 123.83 (C-3), 123.38 (C-K), 123.20 (C-C), 122.51 (C-1), 122.29 (C-13), 120.83 (C-6), 119.09 (C-9), 118.96 (C-8), 118.71 (C-H), 105.82 (acetylene carbon), 95.00 (acetylene carbon), 55.23 (C-g’), 55.04 (C-g), 41.37 (C-f’), 40.11 (C-f), 31.55 (C-e, C-e’), 29.71 (C-d’), 29.59 (C-d), 23.85 (C-c, C-c’), 22.61 (C-b, C-b’), 14.08 (C-a), 13.96 (C-a’), 0.01 ppm (methyl carbon atoms of the TMS group). HRMS (MALDI-TOF): m/z: calcd for C106H124N4Si: 1480.9596 [M]+; found: 1480.9642.
7,7’-{7-[(Trimethylsilyl)ethynyl]pyridoACHTUNGTRENNUNG[2,3-b]pyrazine-2,3-diyl}bis(9,9-di-hexyl-N,N-diphenyl-9H-fluoren-2-amine) (9): PdCl2ACHTUNGTRENNUNG(PPh3)2 (0.06 g,
0.09 mmol), CuI (0.03 g, 0.15 mmol), trimethylsilyl acetylene (0.22 g, 2.23 mmol), and iPr2NH (2.5 mL) were added to a mixture of 6 (1.80 g,
1.49 mmol) in dry THF (10 mL). The resulting solution was stirred at 90 8C under an Ar atmosphere for 24 h. After cooling to room tempera-ture, H2O ( 100 mL) was added to the reaction mixture. The above
so-lution was then extracted with CH2Cl2(3 30 mL), and the organic layer
was collected and dried with MgSO4(s). After removing the solvent, the
crude product was purified by column chromatography on silica gel (THF/hexane = 1:10) to give the final purified product as an orange powder (1.53 g, 83.9 %). 1H NMR (300 MHz, CDCl 3): d = 9.16–9.12 (d, J = 2.1 Hz, 1 H; H-B), 8.58–8.54 (d, J = 2.1 Hz, 1 H; H-E), 7.82–7.78 (d, J = 1.2 Hz, 1 H; H-15), 7.71–7.14 (dd, J = 8.1, 1.2 Hz, 1 H; H-12), 7.63–7.58 (d, J = 8.1 Hz, 1 H; 12’), 7.57–7.42 (m, 5 H; 13, 13’, 9, 9’, H-15’), 7.31–7.21 (m, 8 H; H-3), 7.15–7.07 (m, 10 H; H-2, H-6), 7.07–6.97 (m, 6 H; 1, 8), 1.82–1.61 (m, 8 H; f, f’), 1.14–0.92 (m, 24 H; c, H-c’, H-d, H-d’, H-e, H-e’), 0.81–0.75 (m, 12 H; H-a, H-a’), 0.62 (s, 8 H; H-b, H-b’), 0.33 ppm (s, 9 H; methyl hydrogen atoms of the TMS group);
13C NMR (75 MHz, CDCl
3, tentative assignments based on calculated
values): d = 156.91 (C-G), 155.93 (C-F), 155.72 (C-B), 152.75 (C-16), 152.62 (16’), 150.71 (5), 150.55 (5’), 148.75 (C), 147.83 (4, C-4’), 147.71 (C-7, C-7’), 142.53 (C-11), 142.30 (C-11’), 139.97 (C-E), 136.49 (C-14), 136.08 (C-14’), 135.20 (C-10), 135.14 (C-10’), 134.95 (C-D), 129.72 (C-12), 129.14 (C-2, C-2’), 128.91 (C-12’), 124.45 (C-15), 124.31 (C-15’), 123.92 (C-3, C-3’), 123.29 (C-13, C-13’), 122.62 (C-1, C-1’), 121.18 (C-A), 120.99 6), 120.93 6’), 119.13 9), 118.89 8, C-8’), 118.56 (C-13’), 100.99 (acetylene carbon), 100.81 (acetylene carbon), 55.23 (C-g), 55.05 g’), 40.18 f), 40.05 f’), 31.57 e), 31.52 e’), 29.54
(C-d, C-d’), 23.84 (C-c), 23.77 (C-c’), 22.58 (C-b, C-b’), 14.06 (C-a, C-a’), 0.25 ppm (methyl carbon atoms on TMS group). HRMS (MALDI-TOF): m/z: calcd for C86H95N5Si: 1226.8258 [M]
+
; found: 1226.8293. 7,7’-(6-Ethynylquinoxaline-2,3-diyl)bis(9,9-dihexyl-N,N-diphenyl-9H-fluo-ren-2-amine) (10): KOH (0.26 g, 4.57 mmol) was added to a mixture of 7 (1.4 g, 1.14 mmol) in THF/MeOH (5 mL/1 mL), and the resulting solu-tion was stirred at RT under an Ar atmosphere for 15 h. Upon comple-tion of the reaccomple-tion, H2O ( 100 mL) was added to the reaction mixture.
The above solution was then extracted with CH2Cl2(3 30 mL), and the
organic layer was collected and dried with MgSO4(s). After removing the
solvent, the crude product was purified by column chromatography on silica gel (THF/hexane = 1:10) to give the final purified product as an orange powder (1.1 g, 83.4 %).1H NMR (300 MHz, CDCl 3): d = 8.35–8.34 (d, J = 1.2 Hz, 1 H; H-F), 8.13–8.10 (d, J = 8.7 Hz, 1 H; H-C), 7.80–7.77 (d, J = 8.7, 1.2 Hz, 1 H; H-B), 7.59–7.50 (m, 8 H; H-9, H-12, H-13, H-15), 7.27–7.21 (m, 8 H; H-2), 7.12–7.08 (m, 10 H; H-3, H-6), 7.08–6.98 (m, 6 H; H-1, H-8), 3.27 (s, 1 H; C H), 1.74 (s, 8 H; f), 1.13–0.94 (m, 24 H; H-c, H-d, H-e), 0.86–0.76 (m, 12 H; H-a), 0.64 ppm (s, 8 H; H-b);13C NMR
(75 MHz, CDCl3, tentative assignments based on calculated values): d =
154.79 (C-G), 154.50 (C-H), 152.63 (C-16), 150.60 (C-5), 147.88 (C-4), 147.54 D, C-E), 141.88 11), 140.95 7), 140.62 A), 136.97 (C-14), 135.35 (C-10), 133.07 (C-F), 132.48 (C-B), 129.15 (C-2), 129.00 (C-12, C-C), 124.35 15), 123.88 3), 123.33 13), 122.57 1), 120.89 (C-8), 119.01 (C-9, C-6), 83.07 (acetylene carbon), 79.55 (acetylene carbon), 55.07 (C-g), 40.09 (C-f), 31.53 (C-e), 29.57 (C-d), 23.83 (C-c), 22.60 (C-b), 14.08 ppm (C-a). HRMS (MALDI-TOF): m/z: calcd for C84H88N4:
1152.7009 [M]+; found: 1152.7042.
7,7’-(8-Ethynyl-10,10-dihexyl-10H-indenoACHTUNGTRENNUNG[2,1-g]quinoxaline-2,3-diyl)-bis(9,9-dihexyl-N,N-diphenyl-9H-fluoren-2-amine) (11): KOH (0.27 g, 4.85 mmol) was added to a mixture of 8 (2.4 g, 1.62 mmol) in THF/ MeOH (10 mL/2 mL), and the resulting solution was stirred at RT under an Ar atmosphere for 5 h. Upon completion of the reaction, H2O (
100 mL) was added to the reaction mixture. The above solution was then extracted with CH2Cl2(3 30 mL), and the organic layer was
col-lected and dried with MgSO4(s). After removing the solvent, the crude
product was purified by column chromatography on silica gel (THF/ hexane = 1:10) to give the final purified product as an orange powder (2.1 g, 92 %).1H NMR (300 MHz, CDCl 3): d = 8.44 (s, 1 H; H-H), 8.10 (s, 1 H; H-K), 7.89–7.86 (d, J = 7.8 Hz, 1 H; H-D), 7.63–7.52 (m, 10 H; H-9, H-12, H-13, H-15, H-B, H-E), 7.27–7.22 (m, 8 H; H-2), 7.14–7.09 (m, 10 H; H-3, H-6), 7.03–6.99 (m, 6 H; H-1, H-8), 3.20 (s, 1 H; C H), 2.13– 2.02 (m, 4 H; H-f’), 1.84–1.74 (m, 8 H; H-f), 1.11–1.04 (m, 36 H; H-c, H-c’, H-d, H-d’, H-e, H-e’), 0.86–0.66 ppm (m, 30 H; H-a, H-a’, H-b, H-b’);
13C NMR (75 MHz, CDCl
3, tentative assignments based on calculated
values): d = 153.48 (C-16), 153.40 (C-16’), 153.11 (C-N), 152.58 (C-5), 151.34 (C-M), 150.58 (C-A), 150.50 (C-L), 147.89 (C-4), 147.41 (C-F), 143.00 (C-J), 141.54 (C-I), 141.39 (C-G), 141.16 (C-11), 140.35 (C-7), 137.49 (14), 137.41 (14’), 135.52 (10), 131.56 (B), 129.12 (2, C-12), 128.92 E), 126.79 D), 124.36 15), 123.83 3), 123.37 (C-K), 122.52 (C-1), 122.35 (C-13), 122.14 (C-C), 120.90 (C-6), 120.82 (C-6’), 119.08 (C-9), 118.96 (C-8), 118.90 (C-8’), 118.82 (C-H), 84.35 (acetylene carbon), 77.92 (acetylene carbon), 55.23 (C-g’), 55.04 (C-g), 41.32 (C-f’), 40.11 (C-f), 31.54 (C-e, C-e’), 29.67 (C-d’), 29.58 (C-d), 23.84 (C-c, C-c’), 22.61 (C-b), 22.55 (C-b’), 14.07 (C-a), 13.94 ppm (C-a’). HRMS (MALDI-TOF): m/z: calcd for C103H116N4: 1408.9200 [M]
+
; found: 1408.9240.
7,7’-(7-EthynylpyridoACHTUNGTRENNUNG[2,3-b]pyrazine-2,3-diyl)bis(9,9-dihexyl-N,N-diphen-yl-9H-fluoren-2-amine) (12): KOH (0.28 g, 4.99 mmol) was added to a mixture of 9 (1.53 g, 1.24 mmol) in THF/MeOH/H2O (10 mL/5 mL/
1 mL), and the resulting solution was stirred at RT under an Ar atmos-phere for 2 h. After cooling to room temperature, H2O ( 100 mL) was
added to the reaction mixture. The above solution was then extracted with CH2Cl2 (3 30 mL), and the organic layer was collected and dried
with MgSO4(s). After removing the solvent, the crude product was
puri-fied by column chromatography on silica gel (THF/hexane = 1:10) to give the final purified product as an orange powder (1.1 g, 76.3 %).1H NMR
(300 MHz, CDCl3): d = 9.16–9.15 (d, J = 2.1 Hz, 1 H; H-B), 8.61–8.60 (d,
H-12), 7.64–7.58 (d, J = 7.8 Hz, 1 H; H-12’), 7.59–7.43 (m, 5 H; H-13, H-13’, H-9, H-9’, H-15’), 7.27–7.21 (m, 8 H; H-2), 7.20–7.10 (m, 10 H; H-3, H-6), 7.08–6.98 (m, 6 H; H-1, H-8), 3.42 (s, 1 H; C H), 1.81–1.68 (m, 8 H; H-f, H-f’), 1.26–1.02 (m, 24 H; H-c, H-c’, H-d, H-d’, H-e, H-e’), 0.92–0.78 (m, 12 H; H-a, H-a’), 0.77–0.75 ppm (m, 8 H; H-b, H-b’); 13C NMR
(75 MHz, CDCl3, tentative assignments based on calculated values): d =
157.25 (C-G), 156.09 (C-F), 155.56 (C-B), 152.76 (C-16), 152.62 (C-16’), 150.75 (C-5), 150.56 (C-5’), 148.99 (C-C), 147.81 (C-4, C-4’), 142.62 (C-7, C-7’), 142.38 (C-11, C-11’), 140.60 (C-E), 136.38 (C-14), 135.97 (C-14’), 135.13 (C-10, C-10’), 134.83 (C-D), 129.73 (C-12), 129.15 (C-2, C-2’), 128.90 (C-12’), 124.45 (C-15), 124.28 (C-15’), 123.93 (C-3, C-3’), 123.27 (C-13, C-13’), 122.64 (C-1, C-1’), 121.01 (C-6, C-6’), 120.09 (C-A), 119.19 (C-9), 118.86 (C-8, C-8’), 118.56 (C-9’), 82.57 (acetylene carbon), 79.97 (acetylene carbon), 55.24 (C-g), 55.06 (C-g’), 40.17 (C-f), 40.05 (C-f’), 31.57 (C-e), 31.51 (C-e’), 29.54 (C-d, C-d’), 23.85 (C-c, C-c’), 22.58 (C-b, C-b’), 14.05 ppm (C-a, C-a’). HRMS (MALDI-TOF): m/z: calcd for C83H87N5: 1153.6962 [M]
+; found: 1153.6965.
Compound 1: PdACHTUNGTRENNUNG(PPh3)4(0.015 g, 0.011 mmol), CuI (3 mg, 0.011 mmol),
tetraiodoethene (0.12 g, 0.23 mmol), and NEt3 (3 mL) were added to
a mixture of 10 (1.1 g, 0.95 mmol) in THF (10 mL). The resulting solution was stirred at 90 8C under an Ar atmosphere for 26 h. After cooling to room temperature, H2O ( 100 mL) was added to the reaction mixture.
The above solution was then extracted with CH2Cl2(3 30 mL), and the
organic layer was collected and dried with MgSO4(s). After removing the
solvent, the crude product was purified by column chromatography on silica gel (THF/hexane = 1:10) to give the final purified product as a yellow powder (0.6 g, 57.1 %). 1H NMR (300 MHz, CDCl 3): d = 8.43– 8.42 (d, J = 1.2 Hz, 4 H; H-F), 8.16–8.13 (d, J = 8.7 Hz, 4 H; H-C), 7.86– 7.82 (d, J = 8.7, 1.2 Hz, 4 H; H-B), 7.60–7.50 (m, 32 H; H-9, H-12, H-13, H-15), 7.27–7.21 (m, 32 H; H-2), 7.13–7.09 (m, 40 H; H-3, H-6), 7.03–6.99 (m, 24 H; H-1, H-8), 1.76–1.74 (m, 32 H; H-f), 1.14–1.04 (m, 96 H; H-c, H-d, H-e), 0.82–0.76 (m, 48 H; H-a), 0.65 ppm (s, 32 H; H-b);13C NMR
(75 MHz, CDCl3, tentative assignments based on calculated values): d =
155.00 (C-H), 154.67 (C-G), 152.64 (C-16), 150.64 (C-5), 150.58 (C-5’), 147.86 (C-4), 147.56 (C-E), 141.99 (C-11), 141.93 (C-D), 141.30 (C-7), 140.64 (C-A), 136.88 (C-14), 135.31 (C-10), 133.74 (C-F), 132.48 (C-B), 129.42 (C-C), 129.14 (C-2), 129.04 (C-12), 124.35 (C-15), 123.89 (C-3), 123.32 13), 122.70 (ethylene carbon atoms), 122.58 1), 120.90 (C-8), 118.97 (C-9, C-6), 82.22 (acetylene carbon atoms), 76.16 (acetylene carbon atoms), 55.07 (C-g), 40.08 (C-f), 31.53 (C-e), 29.56 (C-d), 23.83 (C-c), 22.60 (C-b), 14.07 ppm (C-a). HRMS (MALDI-TOF): m/z: calcd for C338H348N6: 4635.6206 [M]+; found: 4635.6372.
Compound 2: PdACHTUNGTRENNUNG(PPh3)4(0.02 g, 0.018 mmol), CuI (3.37 mg, 0.018 mmol),
tetraiodoethene (0.19 g, 0.35 mmol), and NEt3 (3.6 mL) were added to
a mixture of 11 (2.1 g, 1.48 mmol) in THF (12 mL). The resulting solution was stirred at 90 8C under an Ar atmosphere for 12 h. After cooling to room temperature, H2O ( 100 mL) was added to the reaction mixture.
The above solution was then extracted with CH2Cl2(3 30 mL), and the
organic layer was collected and dried with MgSO4(s). After removing the
solvent, the crude product was purified through column chromatography on silica gel (THF/hexane = 1:10) to give the final purified product as an orange powder (1.1 g, 55 %). 1H NMR (300 MHz, CDCl 3): d = 8.46 (s, 4 H; H-H), 8.11 (s, 4 H; H-K), 7.92–7.89 (d, J = 7.8 Hz, 4 H; H-D), 7.65– 7.52 (m, 40 H; 9, 12, 13, 15, B, E), 7.27–7.22 (m, 32 H; H-2), 7.13–7.09 (m, 40 H; H-3, H-6), 7.03–6.98 (m, 24 H; H-1, H-8), 2.14– 2.11 (m, 16 H; H-f’), 1.76–1.74 (m, 32 H; H-f), 1.13–1.04 (m, 144 H; H-c, c’, d, d’, e, e’), 0.82–0.68 ppm (m, 120 H; a, a’, b, H-b’);13C NMR (75 MHz, CDCl
3, tentative assignments based on calculated
values): d = 153.57 (C-16), 153.44 (C-16’), 153.23 (C-N), 152.60 (C-5), 151.49 (C-M), 150.60 (C-A), 150.53 (C-L), 147.91 (C-4), 147.43 (C-F), 142.84 (C-J), 141.59 (C-I), 141.54 (C-G), 141.49 (C-C), 141.18 (C-11), 140.86 (C-7), 137.47 (C-14), 137.39 (C-14’), 135.53 (C-10), 131.97 (C-B), 129.13 2, C-12), 128.92 E), 127.24 D), 124.37 15), 123.85 (C-3), 123.39 (C-K), 122.53 (C-1), 121.80 (ethylene carbon atoms), 121.14 (C-13), 120.83 (C-6), 119.10 (C-9, C-8, C-H), 83.21 (acetylene carbon atoms), 74.98 (acetylene carbon atoms), 55.29 (C-g’), 55.06 (C-g), 41.33 (C-f’), 40.12 (C-f), 31.55 (C-e, C-e’), 29.69 (C-d’), 29.59 (C-d), 23.85 (C-c, C-c’), 22.62 (C-b, C-b’), 14.08 (C-a), 13.96 ppm (C-a’). HRMS (MALDI-TOF): m/z: calcd for C414H460N16: 5660.3447 [M]
+; found: 5660.3721.
Compound 3: PdACHTUNGTRENNUNG(PPh3)4 (0.013 g, 0.011 mmol), CuI (2.16 mg,
0.011 mmol), tetraiodoethene (0.12 g, 0.22 mmol), and NEt3 (2.5 mL)
were added to a mixture of 12 (1.1 g, 0.95 mmol) in THF (10 mL). The resulting solution was stirred at 90 8C under an Ar atmosphere for 18 h. After cooling to room temperature, H2O ( 100 mL) was added to the
reaction mixture. The above solution was then extracted with CH2Cl2(3
30 mL), and the organic layer was collected and dried with MgSO4(s).
After removing the solvent, the crude product was purified by column chromatography on silica gel (THF/hexane = 1:10) to give the final puri-fied product as a red powder (0.5 g, 47.6 %). 1H NMR (300 MHz,
CDCl3): d = 9.23–9.22 (d, J = 2.1 Hz, 4 H; H-B), 8.70–8.69 (d, J = 2.1 Hz, 4 H; H-E), 7.83 (s, 4 H; H-15), 7.73–7.70 (dd, J = 8.1, 1.2 Hz, 4 H; H-12), 7.70–7.63 (d, J = 8.1 Hz, 4 H; H-12’), 7.60–7.57 (d, J = 8.1 Hz, 8 H; H-13, H-13’), 7.52–7.48 (d, J = 8.1 Hz, 4 H; H-9), 7.48–7.44 (m, 8 H; H-9’, H-15’), 7.27–7.22 (m, 32 H; H-2), 7.13–7.08 (m, 40 H; H-3, H-6), 7.03–6.99 (m, 24 H; H-1, H-8), 1.84–1.69 (m, 32 H; H-f, H-f’), 1.15–1.03 (m, 96 H; H-c, H-c’, H-d, H-d’, H-e, H-e’), 0.93–0.76 (m, 48 H; H-a, H-a’), 0.63 ppm (s, 32 H; H-b, H-b’);13C NMR (75 MHz, CDCl
3, tentative assignments based
on calculated values): d = 157.48 (C-G), 156.33 (C-F), 155.40 (C-B), 152.73 (C-16), 152.57 (C-16’), 150.71 (C-5), 150.54 (C-5’), 149.17 (C-C), 147.74 4, C-4’), 142.76 7), 142.46 11), 141.08 E), 136.21 (C-14), 135.79 (C-14’), 134.99 (C-10, C-A), 134.67 (C-D), 129.75 (C-12), 129.10 (C-2), 124.42 (C-15), 124.21 (C-15’), 123.90 (C-3), 123.20 (C-13), 122.61 (C-1), 121.01 (C-6), 119.27 (C-9), 119.18 (ethylene carbon atoms), 118.76 (C-8), 118.56 (C-9’), 79.95 (acetylene carbon atoms), 78.38 (acety-lene carbon atoms), 55.19 (C-g), 55.01 (C-g’), 40.09 (C-f), 31.51 (C-e), 31.50 (C-e’), 29.48 (C-d), 23.79 (C-c), 22.53 (C-b), 14.01 ppm (C-a).
Acknowledgements
We thank the National Science Council (NSC), Taiwan for financial sup-port through grant number 101-2113M-008-003-MY2.
[1] a) S. Yao, K. D. Belfield, Eur. J. Org. Chem. 2012, 3199 – 3217; b) M. Pawlicki, H. A. Collins, R. G. Denning, H. L. Anderson, Angew. Chem. Int. Ed. 2009, 48, 3244 – 3266; Angew. Chem. 2009, 121, 3292 – 3316; c) H. M. Kim, B. R. Cho, Acc. Chem. Res. 2009, 42, 863 – 872; d) M. Rumi, S. Barlow, J. Wang, J. W. Perry, S. R. Marder, Advances in Polymer Science Vol. 213: Photoresponsive Polymers I (Eds.: S. R. Marder, K.-S. Lee), 2008, Springer, Berlin, pp. 1 – 95; e) K. D. Bel-field, S. Yao, M. V. Bondar, Advances in Polymer Science Vol. 213: Photoresponsive Polymers I (Eds.: S. R. Marder, K.-S. Lee), 2008, Springer, Berlin, pp. 97 – 156; f) G. S. He, L.-S. Tan, Q. Zheng, P. N. Prasad, Chem. Rev. 2008, 108, 1245 – 1330; g) T.-C. Lin, S.-J. Chung, K.-S. Kim, X. Wang, G. S. He, J. Swiatkiewicz, H. E. Pudavar, P. N. Prasad, Advances in Polymer Science Vol. 161: Polymers for Photon-ics Applications II (Ed.: K.-S Lee), 2003, Springer, Berlin, pp. 157 – 193; h) C. W. Spangler, J. Mater. Chem. 1999, 9, 2013 – 2020; i) Q. Zheng, H. Zhu, S.-C. Chen, C. Tang, E. Ma, X. Chen, Nat. Photonics 2013, 7, 234 – 239.
[2] a) H. M. Kim, B. R. Cho, Chem. Commun. 2009, 153 – 164; b) F. Ter-enziani, C. Katan, E. Badaeva, S. Tretiak, M. Blanchard-Desce, Adv. Mater. 2008, 20, 4641 – 4678.
[3] a) M. Albota, D. Beljonne, J.-L. Brdas, J. E. Ehrlich, J.-Y. Fu, A. A. Heikal, S. E. Hess, T. Kogej, M. D. Levin, S. R. Marder, D. McCord-Maughon, J. W. Perry, H. Rockel, M. Rumi, G. Subramaniam, W. W. Webb, X.-L. Wu, C. Xu, Science 1998, 281, 1653 – 1656; b) M. Rumi, J. E. Ehrlich, A. A. Heikal, J. W. Perry, S. Barlow, Z. Hu, D. McCord-Maughon, T. C. Parker, H. Rçel, S. Thayumanavan, S. R. Marder, D. Beljonne, J.-L. Brdas, J. Am. Chem. Soc. 2000, 122, 9500 – 9510.
[4] a) L. Porrs, C. Katan, O. Mongin, T. Pons, J. Mertz, M. Blanchard-Desce, J. Mol. Struct. 2004, 704, 17 – 24; b) L. Porrs, O. Mongin, C. Katan, M. Charlot, T. Pons, J. Mertz, M. Blanchard-Desce, Org. Lett. 2004, 6, 47 – 50; c) C. Katan, F. Terenziani, O. Mongin, M. H. V.
Werts, L. Porrs, T. Pons, J. Mertz, S. Tretiak, M. Blanchard-Desce, J. Phys. Chem. A 2005, 109, 3024 – 3037; d) F. Terenziani, C. L. Drou-maguet, C. Katan, O. Mongin, M. Blanchard-Desce, ChemPhys-Chem 2007, 8, 723 – 734; e) J. C. Collings, S.-Y. Poon, C. L. Drouma-guet, M. Charlot, C. Katan, L.-O. Palsson, A. Beeby, J. A. Mosely, H. M. Kaiser, D. Kaufmann, W.-Y. Wong, M. Blanchard-Desce, T. B. Marder, Chem. Eur. J. 2009, 15, 198 – 208; f) F. Terenziani, V. Partha-sarathy, A. Pla-Quintana, T. Maishal, A.-M. Caminade, J.-P. Majoral, M. Blanchard-Desce, Angew. Chem. Int. Ed. 2009, 48, 8691 – 8694; Angew. Chem. 2009, 121, 8847 – 8850.
[5] a) M. Drobizhev, A. Karotki, A. Rebane, C. W. Spangler, Opt. Lett. 2001, 26, 1081 – 1083; b) M. Drobizhev, A. Karotki, Y. Dzenis, A. Rebane, Z. Suo, C. W. Spangler, J. Phys. Chem. B 2003, 107, 7540 – 7543; c) M. Drobizhev, A. Rebanea, Z. Suoc, C. W. Spangler, J. Lumin. 2005, 111, 291 – 305; d) M. Drobizhev, F. Meng, A. Rebane, Y. Stepanenko, E. Nickel, C. W. Spangler, J. Phys. Chem. B 2006, 110, 9802 – 9814.
[6] a) K. D. Belfield, A. R. Morales, J. M. Hales, D. J. Hagan, E. W. V. Stryland, V. M. Chapela, J. Percino, Chem. Mater. 2004, 16, 2267 – 2273; b) K. D. Belfield, A. R. Morales, B.-S. Kang, J. M. Hales, D. J. Hagan, E. W. Van Stryland, V. M. Chapela, J. Percino, Chem. Mater. 2004, 16, 4634 – 4641; c) S. Yao, K. D. Belfield, J. Org. Chem. 2005, 70, 5126 – 5132; d) K. D. Belfield, M. V. Bondar, F. E. Hernandez, O. V. Przhonska, J. Phys. Chem. C 2008, 112, 5618 – 5622; e) X. Wang, D. M. Nguyen, C. O. Yanez, L. Rodriguez, H.-Y. Ahn, M. V. Bondar, K. D. Belfield, J. Am. Chem. Soc. 2010, 132, 12237 – 12239. [7] a) Y. Wang, G. S. He, P. N. Prasad, T. Goodson, III, J. Am. Chem. Soc. 2005, 127, 10128 – 10129; b) A. Bhaskar, G. Ramakrishna, Z. Lu, R. Twieg, J. M. Hales, D. J. Hagan, E. V. Stryland, T. Goodson, III, J. Am. Chem. Soc. 2006, 128, 11840 – 11849; c) A. Bhaskar, R. Guda, M. M. Haley, T. Goodson, III, J. Am. Chem. Soc. 2006, 128, 13972 – 13973; d) O. Varnavski, X. Yan, O. Mongin, M. Blanchard-Desce, T. Goodson, III, J. Phys. Chem. C 2007, 111, 149 – 162; e) M. Williams-Harry, A. Bhaskar, G. Ramakrishna, T. Goodson, III, M. Imamura, A. Mawatari, K. Nakao, H. Enozawa, T. Nishina-ga, M. Iyoda, J. Am. Chem. Soc. 2008, 130, 3252 – 3253.
[8] a) B. A. Reinhardt, L. L. Brott, S. J. Clarson, A. G. Dillard, J. C. Bhatt, R. Kannan, L. Yuan, G. S. He, P. N. Prasad, Chem. Mater. 1998, 10, 1863 – 1874; b) R. Kannan, G. S. He, L. Yuan, F. Xu, P. N. Prasad, A. G. Dombroskie, B. A. Reinhardt, J. W. Baur, R. A. Vaia, L.-S. Tan, Chem. Mater. 2001, 13, 1896 – 1904; c) R. Kannan, G. S. He, T.-C. Lin, P. N. Prasad, R. A. Vaia, L.-S. Tan, Chem. Mater. 2004, 16, 185 – 194; d) S.-J. Chung, K.-S. Kim, T.-C. Lin, G. S. He, J. Swiatkiewicz, P. N. Prasad, J. Phys. Chem. B 1999, 103, 10741 – 10745; e) T.-C. Lin, G. S. He, P. N. Prasad, L.-S. Tan, J. Mater. Chem. 2004, 14, 982 – 991; f) Q. Zheng, G. S. He, P. N. Prasad, Chem. Mater. 2005, 17, 6004 – 6011.
[9] a) H. J. Lee, J. Sohn, J. Hwang, S. Y. Park, H. Choi, M. Cha, Chem. Mater. 2004, 16, 456 – 465; b) Z. Fang, T.-L. Teo, L. Cai, Y.-H. Lai, A. Samoc, M. Samoc, Org. Lett. 2009, 11, 1 – 4; c) Z. Fang, X. Zhang, Y.-H. Lai, B. Liu, Chem. Commun. 2009, 920 – 922; d) Y. Xie, X. Zhang, Y. Xiao, Y. Zhang, F. Zhou, J. Qi, J. Qu, Chem. Commun. 2012, 48, 4338 – 4340; e) C. Tang, Q. Zheng, H. Zhu, L. Wang, S.-C. Chen, E. Ma, X. Chen, J. Mater. Chem. C 2013, 1, 1771 – 1780.
[10] a) T.-C. Lin, Y.-F. Chen, C.-L. Hu, C.-S. Hsu, J. Mater. Chem. 2009, 19, 7075 – 7080; b) T.-C. Lin, W.-L. Lin, C.-M. Wang, C.-W. Fu, Eur. J. Org. Chem. 2011, 912 – 921; c) T.-C. Lin, Y.-H. Lee, C.-Y. Liu, B.-R. Huang, M.-Y. Tsai, Y.-J. Huang, Chem. Eur. J. 2013, 19, 749 – 760; d) T.-C. Lin, M.-H. Li, C.-Y. Liu, J.-H. Lin, Y.-K. Shen, Y.-H. Lee, J. Mater. Chem. C 2013, 1, 2764 – 2772; e) T.-C. Lin, F.-L. Guo, M.-H. Li, C.-Y. Liu, Chem. Asian J. 2013, 8, 2102 – 2110.
[11] a) C. Bosshard, R. Spreiter, P. Gnter, R. R. Tykwinski, M. Schreib-er, F. Diederich, Adv. Mater. 1996, 8, 231 – 234; b) U. GublSchreib-er, R. R. Spreiter, C. Bosshard, P. Gnter, R. R. Tykwinski, F. Diederich, Appl. Phys. Lett. 1998, 73, 2396 – 2398; c) F. Diederich, Chem. Commun. 2001, 219 – 227; d) A. Sune Andersson, K. Qvortrup, E. R. Torbensen, J.-P. Mayer, J.-P. Gisselbrecht, C. Boudon, M. Gross, A. Kadziola, K. Kils, M. B. Nielsen, Eur. J. Org. Chem. 2005, 3660 – 3671; e) A. S. Andersson, L. Kerndrup, A. Ø. Madsen, K. Kils, M. B. Nielsen, P. R. La Porta, I. Biaggio, J. Org. Chem. 2009, 74, 375 – 382.
[12] a) T.-C. Lin, W. Chien, C.-Y. Liu, M.-Y. Tsai, Y.-J. Huang, Eur. J. Org. Chem. 2013, 4262 – 4269; b) T.-C. Lin, C.-Y. Liu, M.-H. Li, Y.-Y. Liu, S.-Y.-Y. Tseng, Y.-Y.-T. Wang, Y.-Y.-H. Tseng, H.-H. Chu, C.-W. Luo, J. Mater. Chem. C 2014, 2, 821 – 828.
[13] a) M. Parent, O. Mongin, K. Kamada, C. Katan, M. Blanchard-Desce, Chem. Commun. 2005, 2029 – 2031; b) C. Le Droumaguet, O. Mongin, M. H. V. Werts, M. Blanchard-Desce, Chem. Commun. 2005, 2802 – 2804; c) F. Terenziani, A. Painelli, C. Katan, M. Charlot, M. Blanchard-Desce, J. Am. Chem. Soc. 2006, 128, 15742 – 15755; d) A. Painelli, F. Terenziani, Z. G. Soos, Theor. Chem. Acc. 2007, 117, 915 – 931.
[14] C. Liu, K.-C. Tang, H. Zhang, H.-A. Pan, J. Hua, B. Li, P.-T. Chou, J. Phys. Chem. A 2012, 116, 12339 – 12348.
[15] C. Xu, W. W. Webb, J. Opt. Soc. Am. B 1996, 13, 481 – 491. [16] N. S. Makarov, M. Drobizhev, A. Rebane, Opt. Express 2008, 16,
4029 – 4047.
[17] M. G. Kuzyk, J. Chem. Phys. 2003, 119, 8327 – 8334.
[18] a) R. L. Sutherland, M. C. Brant, J. Heinrichs, J. E. Rogers, J. E. Slagle, D. G. McLean, P. A. Fleitz, J. Opt. Soc. Am. B 2005, 22, 1939 – 1948; b) B. Gu, K. Lou, H.-T. Wang, W. Ji, Opt. Lett. 2010, 35, 417 – 419.
[19] a) Y. Morel, A. Irimia, P. Najechalski, Y. Kervella, O. Stephan, P. L. Baldeck, C. Andraud, J. Chem. Phys. 2001, 114, 5391 – 5396; b) P.-A. Bouit, G. Wetzel, G. Berginc, B. Loiseaux, L. Toupet, P. Feneyrou, Y. Bretonnire, K. Kamada, O. Maury, C. Andraud, Chem. Mater. 2007, 19, 5325 – 5335; c) C. Li, K. Yang, Y. Feng, X. Su, J. Yang, X. Jin, M. Shui, Y. Wang, X. Zhang, Y. Song, H. Xu, J. Phys. Chem. B 2009, 113, 15730 – 15733; d) Q. Bellier, N. S. Makarov, P.-A. Bouit, S. Rigaut, K. Kamada, P. Feneyrou, G. Berginc, O. Maury, J. W. Perry, C. Andraud, Phys. Chem. Chem. Phys. 2012, 14, 15299 – 15307. [20] a) M. J. Miller, A. G. Mott, B. P. Ketchel, Proc. SPIE 1998, 3472,
24 – 29; b) J. S. Shirk, Opt. Photonics News, 2000, 4, 19 – 23; c) J. Zhang, Y. Cui, M. Wang, J. Liu, Chem. Commun. 2002, 2526 – 2527. Received: February 20, 2014 Published online: April 25, 2014
