Synthesis, optical and electrochemical properties of 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazole and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]-9H-fluorene derivatives

Article abstract of DOI:10.1515/hc-2015-0124

A series of 2-[(9H-fluoren-2-yl)aryl]-1H-benzo[d]imidazoles 11-13 and 2,7-bis[(1H-benzo[d]imidazol-2-yl)aryl]-9H-fluorenes 14-16 containing different linking aromatic units were synthesized in good yields. Their absorption and fluorescence properties were

Full text of DOI:10.1515/hc-2015-0124

Heterocycl. Commun. 2016; aop
Qing-Feng Li, Min-Jie Li, Hai-Xia Lin*, Pei-Pei Xu, Ze-Bin Gu and Yong-Mei Cui*
Synthesis, optical and electrochemical properties
of 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazole
and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]-
9
H-fluorene derivatives
DOI 10.1515/hc-2015-0124
Due to their rigid oligophenyl unit within the molecu-
lar backbone and the possibility of facile functionaliza-
tion at the methylene bridge, fluorene-based derivatives,
including polymers and oligomers, are important as lumi-
nescent materials [19, 25–28], as well as carrier transport
materials for field effect transistors (FETs) [29–31]. Their
fluorescent characteristics rely largely on molecular struc-
ture and molecular assembly. Changes in the substitution
pattern, conjugation, and molecular electronic struc-
ture can bring about very different optical and physical
properties for such materials. There is presently a great
interest to increase the structural or spatial dimensions of
π conjugated molecules in order to acquire more favorable
physical properties. In continuation of our efforts in syn-
thesizing various fluorescent small molecules [32–35], in
Received June 26, 2015; accepted August 12, 2015
Abstract: A series of 2-[(9H-fluoren-2-yl)aryl]-1H-benzo[d]
imidazoles 11–13 and 2,7-bis[(1H-benzo[d]imidazol-2-yl)
aryl]-9H-fluorenes 14–16 containing different linking
aromatic units were synthesized in good yields. Their
absorption and fluorescence properties were investigated
in solution and in the solid state. Most compounds pos-
sess good fluorescence-emitting ability with ϕFL values in
the region of 0.31–0.99 in solution and display strong blue
emission. Structure–optical behavior characteristics and
further details of the electronic properties from cyclic vol-
tammetry measurements and theoretical calculations are
discussed.
Keywords: 1H-benzo[d]imidazole; fluorene; structure- this paper we describe molecular combinations of fluorene
optical behavior.
and benzo[d]imidazole linked by π-conjugated moiety. We
report the structure-optical behavior characteristics and
further details of the electronic properties from cyclic
voltammetry measurements and theoretical calculations
of novel 2-[(9H-fluoren-2-yl)aryl]-1H-benzo[d]imidazole
Introduction
Fluorescent heterocyclic compounds are of interest as derivatives 11a–c, 12a,b, 13a,b and 2,7-bis[(1H-benzo[d]
emitters for electroluminescence devices, molecular imidazol-2-yl)aryl]-9H-fluorene derivatives 14a–c, 15a,b,
probes for biochemical research, dyes for textiles and 16a,b. Extended conjugation is believed to result in inter-
polymers, fluorescent whitening agents and photo- molecular stacking interactions which are detrimental to
conducting materials [1–9] among other things. In par- the emission characteristics. Therefore, two n-hexyl or two
ticular, imidazole derivatives including phenylbenzo[d] methyl groups were introduced to the C-9 position of the
imidazoles [10–21] and 1,3,5-tris(1-phenylbenzo[d]imida- fluorene moiety to increase solubility as well as to hinder
zol-2-yl)benzene (TPBI) have found applications in electri- intermolecular π-π stacking.
cal and optical materials [22–24].
*
Corresponding authors: Hai-Xia Lin and Yong-Mei Cui,
Results and discussion
The key aldehyde intermediates 3–5 and 7–9 were pre-
pared as shown in Scheme 1. The bromo precursors 2 and
Department of Chemistry, Innovative Drug Research Center,
College of Sciences, Shanghai University, 99 Shangda Road,
Baoshan District, Shanghai 200444, China,
e-mail: haixialin@staff.shu.edu.cn (Hi-Xi Lin);
ymcui@shu.edu.cn (Y.-M. Cui)
Qing-Feng Li, Min-Jie Li, Pei-Pei Xu and Ze-Bin Gu: Department of
Chemistry, Innovative Drug Research Center, College of Sciences,
Shanghai University, 99 Shangda Road, Baoshan District,
Shanghai 200444, China
6
were conveniently converted to the arylated aldehyde
derivatives 3–5 and 7-9 in 70–80% yields by treatment
with the corresponding boronic acids in the presence
of PdCl (PPh ) and K CO under the Suzuki reaction
2
3
2
2
3
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ꢀꢀꢀꢀꢁꢀQ.-F. Li et al.: 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazoles and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]
Br
1
n-C6H13Br
DMSO, rt
KOH
n-C6H13 n-C H
n-C6H13 n-C H
6 13
6
13
Br
Ar
3
, 7 : Ar =
, 8 : Ar =
OH
OH
O
Ar
B
2
3-5
Pd(PPh3)2Cl2, K2CO3
O
S
O
4
o
Toluene, H2O, 90 C
O
5, 9 : Ar =
Br
Br
Ar
Ar
6
7-9
Scheme 1ꢀSynthesis of the aldehyde intermediates.
conditions [36]. Condensation of 3–5 or 7–9 with the maxima at 337 nm, 368 nm, 378 nm, 360 nm, 394 nm,
diaminobenzene derivatives 10 in dioxane at 110°C for and 400 nm in diluted CH Cl solutions, respectively. The
2
2
2
-5 h afforded the target compounds 11a–13b and 14a–16b absorption maxima of 11a–16b follow the order: 11a–c
in 60–80% yields (Scheme 2). All target compounds were (benzene) ꢀ<ꢀ12a,b (furan) ꢀ<ꢀ13a,b (thiophene) (Figure 3),
purified by column chromatography on silica gel and their 14a–c (benzene) ꢀ<ꢀ15a,b (furan) ꢀ<ꢀ16a,b (thiophene).
1
13
molecular structures were confirmed by H NMR, C NMR, This result demonstrates that the heterocyclic ring plays
and HR-MS.
an important role in the UV-vis absorption spectra due
The ORTEP view of the structure of 11b in Figure 1A to the lone pair electrons which can cause n-π* transi-
indicates that the moieties of fluorene, phenylene and tions with lower energy in the heteroatom (O, S). Com-
2
-phenyl-1H-benzo[d]imidazole are non-coplanar with pounds 14a–c, 15a,b, and 16a,b have longer absorption
o
dihedral angles of 7.829 and 33.613°, respectively. In com- wavelengths than 11a–c, 12a,b, and 13a,b due to the
pound 13b, as shown in Figure 2A, the fluorene moiety elongation of conjugation. Compounds 15a,b and 16a,b
forms torsion angle of 13.100° with the adjacent thiophene exhibit the longest absorption wavelengths. Interestingly,
ring ii, and the thiophene ring ii forms a torsion angle of compounds 11b,c, 12b, 13b, 14b,c, 15b and 16b with the
1
8.325° with the imidazole ring iii. The crystal packings of phenyl or para-MeO substituted phenyl group in N-1 posi-
1
1b and 13b are shown in Figures 1B and 2B. The mole- tions have almost the same absorption maxima as those
cules are stacked in the overlapping manner and face-to- of N-H compounds 11a, 12a, 13a, 14a, 15a and 16a, indi-
face π-π intermolecular interactions between molecules cating that arylation of benz[d]imidazole has a limited
can be regarded as the stacking force.
effect on the energy levels of these compounds.
The photophysical properties of compounds 11a–13b
Theoretically, the absorption spectra caused by π-π*
were examined using UV-vis absorption and fluorescence transitions exhibit red shifts with the increase in solvent
spectra in dilute solutions and in solid films. The absorp- polarity. However, compounds 11a–16b show blue-shifted
tion peak wavelengths (λ ) and the emission wavelengths absorption maxima by 5–26 nm in diluted MeOH solu-
abs
(
λem) are listed in Experimental. The emission spectra in tions in comparison with the dilute CH Cl solutions. The
2 2
the solid state were obtained for films spin-coated onto blue-shifted emission in MeOH may be ascribed to hydro-
quartz from chloroform solution. All compounds show gen-bonding interactions, which probably inhibits the
similar absorption profiles, principally owing to π-π* reorientation of the benzo[d]imidazole in the excited state
transitions of the molecular backbone. Compounds by hindering the rotation of the benzene, furan and thio-
1
1a, 12a, 13a, 14a, 15a and 16a exhibit the absorption phene subunits.
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Q.-F. Li et al.: 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazoles and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]ꢂꢁꢀꢀꢀꢂ3
R
n-C6H13 n-C6H13
N
N
1
1a-c
R
R
N
N
n-C6H13 n-C6H13
N
O
1
2a,b
n-C6H13 n-C6H13
N
S
NH2
TsOH (catalyst)
13a,b
3
-9
o
R
N
R
NH
R
dioxane, 90 C
N
1
0a-c
N
N
1
4a-c
R
N
a: R = H
b: R = Ph
c: R = 4-OMe-C6H4
R
N
N
O
N
O
1
5a,b
6a,b
R
N
R
N
N
S
N
S
1
Scheme 2ꢀSynthesis of 11a–16b.
All compounds 11a–16b display blue or blue-green
In comparison with the dilute CH Cl solution, the emis-
2 2
emissions in dilute CH Cl solutions (Figure 4). Com- sion spectra of compounds 11b,c, 12b, 13b, 14b,c and 15a,b
2
2
pounds 11a, 12a, 13a, 14a, 15a and 16a show emission in solid state are shifted to shorter wavelengths by 10–53
peaks at 452 nm, 456 nm, 461 nm, 457 nm, 463 nm and nm. These compounds probably form H-aggregates, which
96 nm, respectively. In contrast to the UV-vis absorption decreases the π-conjugation significantly, in turn, resulting
4
properties, the heteroatom (O, S) and the length of conju- in the observed blue shift [38]. However, compounds 11a,
gation have less significant effects on the emission spectra 12a and 14a show shift to longer wavelengths by 5–8 nm.
of these compounds. A slight red-shift is observed for com- The red shift of the emission observed in the solid state is
pounds 11c and 14c compared with their corresponding probably due to the strong intermolecular forces, which
N-H analogues 11a and 14a. This result attests the partial drive the molecules to pack at high density to form J-aggre-
involvement of the N-substituted chromophores in the gates with restricted molecular rotation and an increased
electronically excited state. By comparison with the dilute π-conjugation, in turn, resulting in the red shift [39].
CH Cl solutions, the emission spectra of all compounds
Most compounds show high fluorescence in CH Cl2
2
2
2
in MeOH solutions show shifts to shorter wavelengths by solution with fluorescence quantum yields ϕFL in the
7–68 nm, probably due to the hydrogen-bonding effects range of 0.77–0.99 (Table 1). The relatively low quantum
in MeOH solutions [37]. yields observed for compounds 13a,b and 15a,b with
3
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ꢀꢀꢀꢀꢁꢀQ.-F. Li et al.: 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazoles and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]
A
A
B
B
c
c
b
0
a
0
b
a
Figure 2ꢀMolecular structures of compound 13b.
The H atoms are omitted for clarity: (A) ORTEP drawing, (B) a view of
the molecule packing structure.
Figure 1ꢀMolecular structures of compound 11b.
The H atoms are omitted for clarity: (A) ORTEP drawing, (B) a view of
the molecule packing structure.
gaps by comparison with compounds 11a–c. The HOMO
energies of these compounds were calculated by using the
ferrocene/ferrocenium redox couple as a reference (4.6 eV)
heteroatoms suggest a fluorescence quenching caused by andwerewithintherangeof5.43–5.84eV.TheLUMOenergies
the heteroatom. were calculated from their corresponding HOMO energies
The redox potentials of all compounds were determined and the optical band gap as estimated from the intersection
by cyclic voltammetry (CV) measurements which were of the absorption and emission peaks, which ranged from
carried out in a three-electrode cell setup with 0.1 M tetrabu- 2.59 eV to 3.36 eV. Compounds 14a–c show relatively higher
tylammonium perchlorate (Bu NClO ) as a supporting elec- HOMO and LUMO energies than 11a–c, probably due to the
4
4
trolyte in anhydrous CH Cl to probe the electrochemical extended length of π-conjugation. However, in the case of
2
2
behavior of the materials. The HOMO values were calculated 15a,b, the HOMO and LUMO are lower in energy than those
as follows: HOMO ꢀ=ꢀ [Eonset]red/ox (vs SCE) + 4.6, E ꢀ=ꢀ 1240/UV of 12a,b; the ability of the heterocyclic ring (furan) to donate
g
(
onset) [40, 41]. As can be seen from Table 1, the band gaps electrons is a possible explanation [42].
(
Eg) of about 2.51–2.92 eV were estimated from the optical
Densityfunctionaltheory(DFT)calculationswerealso
edge. Compounds 12a–15b exhibit relatively smaller band used to characterize the three-dimensional geometries
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Q.-F. Li et al.: 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazoles and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]ꢂꢁꢀꢀꢀꢂ5
and the frontier molecular orbital energy levels of the
1
0
0
0
0
.0
.8
.6
.4
.2
0
11a
representative compounds 11b, 12b, 13b and 14b, 15b,
1
1
1b
1c
16b at the B3LYP/6-31G* level by using the Gaussian 03
program [40, 41]. The orbital plots of the HOMO-LUMO
are illustrated in Figure 5. In the case of compounds 11b,
12a
1
1
1
2b
3a
3b
1
2b, 14b, 15b and 16b, the HOMO and LUMO are mainly
localized on the fluorene and benzene (11b, 14b), furan
12b, 15b), and thiophene (16b) subunits, indicating that
(
the absorption and emission processes are mostly attrib-
uted to the π-π* transitions centered at the fluorene and
aromatic moieties. Interestingly, compound 13b spreads
HOMO and LUMO through the thiophene subunit, which
can explain the relatively high energy level. The LUMO
of all compounds are not localized on the benzo[d]imida-
zole, which can explain the shorter-wavelength absorp-
tions in polar solutions. The trends in the experimentally
observed longer-wavelength absorptions for compounds
3
00
350
400
450
500
Wavelength (nm)
Figure 3ꢀNormalized absorption spectra of 11a–13b (1ꢃ×ꢃ10-5 M)
recorded in CH Cl .
2
2
1
4b and 15b matches well the computed low-energy
excitations.
1
0
0
0
0
.0
.8
.6
.4
.2
1
1
1
1
1
1
1
1a
1b
1c
2a
2b
3a
3b
Conclusions
2
-[(9H-Fluoren-2-yl)aryl]-1H-benzo[d]imidazole and 2,7-bis
[
(1H-benzo[d]imidazol-2-yl)aryl]-9H-fluorene derivatives
containing central aromatic or heteroaromatic subunits
were conveniently synthesized in good yields. These com-
pounds were thoroughly characterized by spectral and
computational methods. Most compounds display emis-
sion in a blue region with ϕFL values in the range of 0.31–
0.99. The HOMO energy levels of about 5.43–5.84 eV and
the LUMO energy levels of about 2.59–3.36 eV were cal-
culated. Further research regarding application of these
systems as organic light-emitting diodes and as fluores-
cent probes is under way in our laboratory.
0
400
450
500
550
600
Wavelength (nm)
Figure 4ꢀNormalized emission spectra of 11a–13b (1ꢃ×ꢃ10-5
M) recorded in CH Cl solutions; excitation at λ at room
2
2
ex
temperature.
Table 1ꢀOptical and electrochemical properties of compounds 11a–15b.
ϕFLaꢁ
HOMObꢁ
LUMOcꢁ
E ꢁ
d
Dyeꢁ
ϕFLaꢁ
HOMObꢁ
LUMOcꢁ
Egd
Dye ꢁ
g
ꢂꢂaꢃ
ꢂꢂbꢃ
ꢂꢂc ꢃ
ꢂꢅaꢃ
ꢂꢅbꢃ
ꢂꢃaꢃ
ꢄ.ꢅ8ꢃ
ꢄ.8ꢇꢃ
ꢄ.8ꢊꢃ
ꢄ.ꢅꢄꢃ
ꢄ.ꢅꢊꢃ
ꢄ.ꢆꢉꢃ
ꢆ.ꢇꢅꢃ
ꢆ.ꢅꢇꢃ
ꢆ.ꢇ3ꢃ
ꢆ.ꢅꢆꢃ
ꢆ.ꢅꢈꢃ
ꢆ.ꢋꢇꢃ
ꢈ.ꢆꢉꢃ
ꢈ.83ꢃ
ꢈ.ꢋꢈꢃ
3.ꢄꢈꢃ
ꢈ.ꢉꢉꢃ
ꢈ.ꢉꢆꢃ
ꢈ.ꢉꢊꢃ
ꢈ.ꢉꢊꢃ
ꢈ.ꢉꢈꢃ
ꢈ.ꢅ3ꢃ
ꢈ.ꢅ3ꢃ
ꢈ.ꢋꢉꢃ
ꢂꢃbꢃ
ꢂꢄaꢃ
ꢂꢄbꢃ
ꢂꢄcꢃ
ꢂꢆaꢃ
ꢂꢆbꢃ
ꢄ.ꢋꢄꢃ
ꢄ.ꢆꢇꢃ
ꢄ.ꢉꢉꢃ
ꢄ.ꢉꢉꢃ
ꢄ.3ꢊꢃ
ꢄ.38ꢃ
ꢆ.8ꢈꢃ
ꢆ.8ꢇꢃ
ꢆ.ꢅꢆꢃ
ꢆ.ꢅꢈꢃ
ꢆ.ꢆꢉꢃ
ꢆ.ꢇ3ꢃ
3.ꢊꢇꢃ
3.3ꢋꢃ
ꢈ.ꢉꢇꢃ
ꢈ.ꢉꢄꢃ
3.ꢄꢄꢃ
ꢈ.8ꢊꢃ
ꢈ.ꢋ8
ꢈ.ꢇ8
ꢈ.8ꢊ
ꢈ.8ꢈ
ꢈ.ꢆꢊ
ꢈ.ꢋꢈ
a
Fluorescence quantum yields measured in CH Cl solution using a 0.1 M H SO solution of quinine sulfate (ϕ ꢃ=ꢃ 0.55) as a reference.
2
2
2
4
FL
b
HOMO energy levels derived from the oxidation potential using EHOMO ꢃ=ꢃ 4.6+E , the redox potentials were measured with cyclic voltamme-
ox
try system.
c
LUMO energy levels were deduced using the formula ELUMO ꢃ=ꢃ EHOMO-Eg.
d
Eg ꢃ=ꢃ 1240/UV(onset). UVs(onset) were estimated from the onset of the absorption spectra.
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ꢀꢀꢀꢀꢁꢀQ.-F. Li et al.: 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazoles and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]
PdCl (PPh ) (0.1 mmol), was added toluene (9 mL) and water (1 mL)
2
3 2
at room temperature. The mixture was heated to 90°C under nitro-
gen atmosphere for 8 h. Af er cooling, the mixture was extracted with
ethyl acetate (10 mL). The organic extract was washed with saturated
brine and dried over Na SO . Af er removing the solvent, the crude
2
4
product was purified by column chromatography on silica gel using
ethyl acetate (1%–2%) in petroleum ether as eluent to afford the final
product 3–5.
4
-(9,9-Dihexyl-9H-fluoren-2-yl)benzaldehyde (3)ꢁThis compound
was obtained from 2 and (4-formylphenyl)boronic acid; yellow oil;
1
yield 80%; H-NMR (CDCl ): δ 10.11 (s, 1H), 8.02 (d, J ꢀ=ꢀ 7.8 Hz, 2H), 7.74
3
13
(
m, 4H), 7.67 (s, 2H), 7.41 (m, 3H), 2.04–2.11 (m, 4H); C-NMR (CDCl ):
3
δ 191.9, 151.7, 151.1, 147.7, 141.8, 140.4, 138.4, 135.1, 130.3, 129.0, 127.7,
1
27.5, 127.0, 126.4, 126.6, 120.2, 120.0, 55.3, 40.4, 31.5, 29.7, 23.8, 22.6,
+
1
4.0. HR-MS. Calcd for C H O ([M + H] ): m/z 439.3001. Found: m/z
32
38
4
39.2995.
5
-(9,9-Dihexyl-9H-fluoren-2-yl)furan-2-carbaldehydeꢀ(4)ꢁThis
compound was obtained from 2 and (5-formylfuran-2-yl)boronic
1
acid; yellow solid; yield 76%; H-NMR (CDCl ): δ 9.68 (s, 1H), 7.86
3
(
d, J ꢀ=ꢀ 1.3 Hz,1H), 7.77 (m, 3H), 7.37 (m, 4H), 6.91 (d, J ꢀ=ꢀ 3.3 Hz,1H),
2
.05 (m, 4H), 1.11 (m, 15H), 0.76 (t, J ꢀ=ꢀ 7.3 Hz, 6H), 0.59-0.68 (m, 4H);
1
3
C-NMR (CDCl ): δ 177.0, 160.4, 151.9, 151.6, 143.0, 140.2, 127.9, 127.6,
3
1
27.0, 124.6, 123.0, 120.1, 119.5, 107.6, 55.4, 40.4, 31.5, 29.7, 29.7, 23.7, 22.6,
+
1
4.0. HR-MS. Calcd for C H O ([M + H] ): m/z 429.2793. Found: m/z
3
0
36
2
4
29.2895.
5
-(9,9-Dihexyl-9H-fluoren-2-yl)thiophene-2-carbaldehyde
(
5)ꢁThis compound was obtained from 2 and (5-formylthiophen-2-yl)
Figure 5ꢀHOMO and LUMO electronic density distributions of 11b,
1
boronic acid; brown yellow solid; yield 71%; H-NMR (CDCl ): δ 9.92
3
1
2b, 13b and 14b, 15b, 16b.
(
(
(
s, 1H), 7.79 (d, J ꢀ=ꢀ 4.4 Hz, 1H), 7.75 (m, 2H), 7.68–7.71 (m, 2H), 7.49
d, J ꢀ=ꢀ 4.3 Hz, 1H), 7.37 (m, 3H), 2.02 (m, 4H), 1.01–1.17 (m, 15H), 0.77
1
3
t, J ꢀ=ꢀ 7.5 Hz, 6H), 0.66 (m, 4H); C-NMR (CDCl ): δ 182.7, 155.3, 151.8,
3
1
1
51.1, 142.0, 140.1, 129.5, 127.8, 127.0, 126.4, 125.5, 124.1, 123.8, 123.0,
Experimental
20.7, 120.3, 120.1, 55.3, 40.3, 31.4, 29.6, 23.7, 22.5, 14.0. HR-MS. Calcd
+
for C H OS ([M + H] ): m/z 445.2565. Found: m/z 445.2535.
3
0
36
Commercially available reagents were purchased and used without
1
13
further purification. H NMR (500 MHz) and C NMR (125 MHz) spectra
were recorded on a Bruker Avance spectrometer in CDCl or DMSO-d .
3
6
1
Chemical shif s in CDCl were referenced to CHCl (7.26 ppm) for H
3
3
General procedure for synthesis of 7–9
13
NMR, and to CDCl3 (77.16 ppm) for C NMR. The center line of the
1
multiplet of DMSO-d was taken as δ 2.50 for H NMR. Silica gel plates
6
To a mixture of 2,7-dibromo-9,9-dimethyl-9H-fluorene (6, 1 mmol),
an aryl boronic acid (2.4 mmol), potassium carbonate (4 mmol),
PdCl (PPh ) (0.2 mmol) was added toluene (9 mL) and water (1 mL)
at room temperature. The mixture was heated to 90°C under nitrogen
atmosphere for 24 h, then cooled and extracted with ethyl acetate (10
mL) and water (10 mL). The organic layer was washed with saturated
brine and dried over Na SO . Af er removing the solvent, the crude
product was purified by column chromatography on silica gel using
ethyl acetate (2%–3%)/petroleum ether as eluent to afford the final
purified product 7–9.
GF254 were used for thin layer chromatography (TLC), and silica gel H
or 300–400 mesh was used for flash column chromatography. Melting
points were measured on a digital melting point apparatus without
correction. The absorption and fluorescence spectra were recorded
using a UV-2501Pc spectrophotometer and a RF-5301 fluorescence
spectrophotometer, respectively. High-resolution mass spectra were
recorded on a Bruker APEX III 7.0 instrument. The redox potentials
of compounds were determined with cyclic voltammetry (CV) using a
Base 2000 CV system. The HOMO values were recalculated from the
2
3 2
2
4
reported literature values as HOMO ꢀ=ꢀ [Eonset]red/ox (vs SCE) + 4.6; E ꢀ=ꢀ
g
1240/UV (onset).
4
,4′-(9,9-Dimethyl-9H-fluorene-2,7-diyl)bisbenzaldehyde
(
7)ꢁThis compound was obtained from 6 and (4-formylphenyl)
1
boronic acid; yellow solid; yield 70%; H-NMR (CDCl ): δ 10.10 (s, 2H),
3
General procedure for synthesis of 3–5
8
1
.01 (d, J ꢀ=ꢀ 8.8 Hz, 3H), 7.87 (m,5 H), 7.71 (m, 5H), 7.46–7.52 (m, 1H),
1
3
.64 (s, 6H); C-NMR (CDCl ): δ 191.9, 154.8, 147.4, 139.9, 135.1, 132.1,
3
To a mixture of 2-bromo-9,9-dihexylfluorene (2) [34] (1 mmol), an 128.6, 127.7, 121.6, 120.8, 47.2, 27.2. HR-MS. Calcd for C H O ([M +
aryl boronic acid (1.2 mmol), potassium carbonate (4 mmol) and Na] ): m/z 425.1518. Found: m/z 425.1516.
29
22
2
+
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Q.-F. Li et al.: 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazoles and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]ꢂꢁꢀꢀꢀꢂ7
5
, 5′-(9,9-Dimethyl-9H-fluorene-2,7- diyl)bis(furan-2- 2.01 (t, J ꢀ=ꢀ 8.5 Hz, 2H), 1.03 (m, 12H), 0.77 (t, J ꢀ=ꢀ 7.4 Hz, 6H), 0.62-
1
3
carbaldehyde) (8)ꢁThis compound was obtained from 6 and 0.70 (m, 4H); C-NMR (CDCl ): δ 159.6, 152.2, 151.4, 150.9, 142.4, 140.9,
3
1
(
5-formylfuran-2-yl)boronic acid; yellow solid; yield 62%; H-NMR 140.6, 138.8, 137.7, 129.7, 128.7, 126.8, 126.8, 125.9, 123.2, 122.9, 122.9,
(
DMSO-d ): δ 9.68 (s, 2H), 7.95 (s, 2H), 7.80-7.86 (m, 5H), 7.67–7.75 121.2, 119.9, 119.8, 119.6, 115.1, 110.4, 55.5, 55.1, 40.4, 31.4, 29.6, 23.7, 22.5,
6
(
(
1
1
4
m, 2H), 7.66–7.11 (m, 1H), 7.48 (m, 2H), 7.38 (d, J ꢀ=ꢀ 4.4 Hz, 2H), 6.94 13.9; λabs (CH Cl ) 333 nm, λ (MeOH) 326 nm; λem (CH Cl ) 462 nm,
2
2
abs
2
2
d, J ꢀ=ꢀ 4.4 Hz, 2H), 1.61 (s, 6H); 1 C-NMR (DMSO-d ): δ 177.1, 159.8, λem (MeOH) 401 nm and 425 nm, λ (film) 452 nm. HR-MS. Calcd for
6 em
+
3
54.9, 152.0, 139.9, 132.1, 132.0, 131.9, 131.9, 128.5, 128.4, 128.4, 124.9, C H N O ([M + H] ): m/z 633.3845. Found: m/z 633.3833.
45
48
2
+
20.9, 119.5, 107.8, 47.3, 26.9. HR-MS. Calcd for C H O ([M + Na] ): m/z
2
5
18
4
05.1103. Found: m/z 405.0640.
General procedure for synthesis of 12a,b and 13a,b
5
,5′-(9,9-Dimethyl-9H-fluorene-2,7-diyl)bis(thiophene-2-
carbaldehyde) (9)ꢁThis compound was obtained from 6 and
1
To a mixture of 5-(9,9-dihexyl-9H-fluoren-2-yl)furan-2-carbalde-
(
(
(
1
1
5-formylthiophen-2-yl)boronic acid; yellow solid; yield 60%; H-NMR
hyde (4, 0.7 mmol) or 5-(9,9-dihexyl-9H-fluoren-2-yl)thiophene-2-
carbaldehyde (5, 0.7 mmol), benzene-1,2-diamine (10a, 1.0 mmol) or
N-phenylbenzene-1,2-diamine (10b, 1.0 mmol), and TsOH (0.1 mmol)
was added dioxane (7 mL) at room temperature. The mixture was
heated under reflux for 9 h. The solvent was removed under reduced
pressure and the crude product was purified by column chromatog-
raphy on silica gel using ethyl acetate (10%–14%)/petroleum ether
as eluent to afford the final product 12 or 13.
DMSO-d ): δ 9.98 (s, 2H), 7.86 (s, 2H), 7.67 (m, 4H), 7.59 (m, 3H), 7.50
6
m, 1H), 7.41 (m, 2H), 7.30 (d, J ꢀ=ꢀ 4.2 Hz, 2H), 6.95 (d, J ꢀ=ꢀ 4.4 Hz, 2H),
13
.59 (s, 6H); C-NMR (DMSO-d ): δ 179.1, 163.6, 158.5, 156.0, 149.9, 145.1,
6
36.0, 135.6, 131.7, 126.5, 123.4, 123.4, 121.2, 119.9, 117.5, 107.1, 45.5, 23.3.
+
HR-MS. Calcd for C H O S ([M + Na] ): m/z 437.0646. Found: m/z
2
5
18
2 2
437.0640.
General procedure for synthesis of 11a–c
2
-[5-(9,9-Dihexyl-9H-fluoren-2-yl)furan-2-yl]-1H-benz[d]imida-
zole (12a)ꢁThis compound was obtained from 4 and 10a; yellow
To
a mixture of 4-(9,9-dihexyl-9H-fluoren-2-yl)benzaldehyde (3,
1
solid; yield 65%; mp 203-206°C; H-NMR (CDCl ): δ 7.74 (m, 5H), 7.34
3
0
.7 mmol), benzene-1,2-diamine, N-phenylbenzene-1,2-diamine or
(
m, 6H), 6.90 (d, J ꢀ=ꢀ 3.6 Hz, 2H), 2.01 (m, 4H), 1.08 (m, 12H), 0.76 (t, J ꢀ=ꢀ
N-(4-methoxyphenyl)benzene-1,2-diamine (10a–c, 1.0 mmol), and
TsOH (0.1 mmol), was added dioxane (7 mL) at room temperature.
The mixture was heated under reflux for 9 h, then concentrated, and
the residue was purified by column chromatography on silica gel
using ethyl acetate (5%–10%)/petroleum ether as eluent to afford the
final product.
1
3
8
.5 Hz, 6H), 0.62 (m, 4H); C-NMR (CDCl ): δ 156.1, 151.4, 150.9, 143.8,
3
1
41.5, 140.4, 128.4, 127.4, 126.8, 123.3, 123.2, 122.8, 120.0, 119.8, 118.3,
13.3, 107.6, 55.2, 40.4, 31.5, 29.7, 23.7, 22.5, 13.9; λabs (CH Cl ) 368 nm,
1
2
2
λabs (MeOH) 364 nm; λem (CH Cl ) 456 nm, λ (MeOH) 394 nm and
2
2
em
+
4
5
17 nm, λem (film) 464 nm. HR-MS. Calcd for C H N O ([M + H] ): m/z
36 40 2
17.3219. Found: m/z 517.3217.
2
-[4-(9,9-Dihexyl-9H-fluoren-2-yl)phenyl]-1H-benz[d]imidazole
2
-[5-(9,9-Dihexyl-9H-fluoren-2-yl)furan-2-yl]-1-phenyl-1H-
(
11a)ꢁThis compound was obtained from 3 and 10a; yellow solid;
benz[d]imidazole (12b)ꢁThis compound was obtained from 4
1
yield 80%; mp ꢀ>ꢀ 400 °C; H-NMR (CDCl ): δ 8.20 (d, J ꢀ=ꢀ 8.3 Hz, 2H),
1
3
and 10b; yellow solid; yield 60%; mp 92–96°C; H-NMR (CDCl ): δ
3
7
.59-7.83 (m, 8H), 7.29-7.40 (m, 5H), 2.03 (m, 4H), 1.01–1.16 (m, 12H),
7
.94 (d, J ꢀ=ꢀ 9.5 Hz, 2H), 7.69 (m, 4H), 7.64 (d, J ꢀ=ꢀ 9.4 Hz, 1H), 7.56 (d,
.77 (t, J ꢀ=ꢀ 7.4 Hz, 6H), 0.68 (m, 4H); 1 C-NMR (CDCl ): δ 151.5, 151.5,
3
0
3
J ꢀ=ꢀ 7.6 Hz, 2H), 7.37 (m, 5H), 7.26 (m, 2H), 7.15 (d, J ꢀ=ꢀ 8.8 Hz, 1H), 6.77
1
51.0, 143.5, 138.7, 128.1, 127.7, 127.2, 126.8, 125.9, 122.9, 121.2, 120.0,
(
d, J ꢀ=ꢀ 3.4 Hz, 1H), 1.95-2.10 (m, 4H), 1.02-1.20 (m, 12H), 0.80 (t, J ꢀ=ꢀ
1
19.8, 55.2, 40.4, 47.2, 23.7, 22.5, 13.9; λabs (CH Cl ) 337 nm, λ (MeOH)
13
2
2
abs
7.4 Hz, 6H), 0.57-0.65 (m, 4H); C-NMR (CDCl ): δ 156.2, 151.2, 150.8,
3
3
4
32 nm; λem (CH Cl ) 452 nm, λ (MeOH) 400, 397 nm, λ (film)
2 2 em em
+
144.1, 143.1, 141.2, 140.5, 137.3, 137.1, 129.8, 129.3, 128.5, 128.1, 127.3,
126.8, 123.4, 123.2, 123.2, 122.8, 119.8, 119.7, 119.5, 118.0, 115.2, 110.2,
60 nm. HR-MS. Calcd for C H N ([M + H] ): m/z 527.3426. Found:
38 43 2
m/z 527.3426.
1
06.2, 106.8, 55.2, 40.4, 31.5, 29.7, 23.6, 22.6, 14.0; λabs (CH Cl ) 371 nm,
2 2
λabs(MeOH) 368 nm; λem (CH Cl ) 469 nm, λ (MeOH) 426 nm, λ
2
2
em
em
2
-[4-(9,9-Dihexyl-9H-fluoren-2-yl)phenyl]-1-phenyl-1H-benz[d]
+
(
film) 462 nm. HR-MS. Calcd for C H N O ([M + H] ): m/z 593.3532.
42 44 2
imidazole (11b)ꢁThis compound was obtained from 3 and 10b;
Found: m/z 593.3538.
1
white solid; yield 75%; mp 147–150°C; H-NMR (CDCl ): δ 7.96 (d, J ꢀ=ꢀ
3
7
.7 Hz, 2H), 7.51-7.78 (m, 11H), 7.27-7.43 (m, 8H), 2.02 (t, J ꢀ=ꢀ 8.6 Hz, 4H),
2
-[5-(9,9-Dihexyl-9H-fluoren-2-yl)thiophen-2-yl]-1H-benz[d]
.09 (m, 12H), 0.77 (t, J ꢀ=ꢀ 7.3 Hz, 6H), 0.68 (m, 4H); 1 C-NMR (CDCl ):
3
1
3
imidazole (13a)ꢁThis compound was obtained from 5 and 10a;
δ 152.1, 151.5, 150.9, 143.0, 142.5, 140.9, 140.6, 138.8, 137.4, 137.1, 129.9,
1
yellow solid; yield 65%; mp 189–192°C; H-NMR (CDCl ): δ 7.72 (m,
3
1
1
3
28.6, 128.5, 127.5, 127.2, 126.9, 126.8, 125.9, 123.3, 122.9, 119.9, 119.8,
3
H), 7.65 (m, 2H), 7.60 (m, 2H), 7.33 (m, 4H), 7.28 (m, 2H), 1.99 (t, J ꢀ=ꢀ
10.4, 55.2, 40.4, 31.4, 29.7, 23.7, 22.5; λabs (CH Cl ) 332 nm, λ (MeOH)
13
2
2
abs
8.6 Hz, 4H), 1.08 (m, 12H), 0.76 (t, J ꢀ=ꢀ 7.4 Hz, 6H), 0.66 (m, 4H); C-
28 nm; λem (CH Cl ) 468 nm, λ (MeOH) 405 nm and 425 nm, λ
film) 444.9 nm. HR-MS. Calcd for C H N ([M + H] ): m/z 603.3739.
2
2
em
em
NMR (CDCl ): δ 151.6, 150.9, 148.2, 147.1, 141.5, 140.3, 132.1, 130.9, 127.9,
127.3, 126.8, 124.8, 123.6, 123.2, 123.2, 122.9, 120.1, 119.8, 55.1, 40.3, 31.4,
3
+
(
44 46 2
Found: m/z 603.3738.
2
9.7, 29.6, 23.7, 22.5, 13.9; λabs (CH Cl ) 378 nm, λ (MeOH) 362 nm; λem
2 2 abs
(
CH Cl ) 461 nm, λ (MeOH) 425 nm, λ (film) 450 nm. HR-MS. Calcd
2 2 em em
+
2
-[4-(9,9-Dihexyl-9H-fluoren-2-yl)phenyl]-1-(4-methoxyphenyl)- for C H N S ([M + H] ): m/z 533.2990. Found: m/z 533.2988.
36 40 2
1
H-benz[d]imidazole (11c)ꢁThis compound was obtained from
1
3
and 10c; white solid; yield 70%; mp 128–130°C; H-NMR (CDCl ): 2-[5-(9,9-Dihexyl-9H-fluoren-2-yl)thiophen-2-yl]-1-phenyl-1H-
3
δ 7.93 (d, J ꢀ=ꢀ 8.5 Hz, 2H), 7.75 (m, 4H), 7.65 (d, J ꢀ=ꢀ 9.3 Hz, 2H), 7.59 (t, benz[d]imidazole (13b)ꢁThis compound was obtained from 5 and
1
J ꢀ=ꢀ 8.5 Hz, 2H), 7.22–7.39 (m, 9H), 7.07 (d, J ꢀ=ꢀ 8.0 Hz, 2H), 3.92 (s, 3H), 10b; green solid; yield 80%; mp 95–97°C; H-NMR (CDCl ): δ 7.93
3
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Authenticated
Download Date | 1/12/16 11:08 PM

8
ꢀꢀꢀꢀꢁꢀQ.-F. Li et al.: 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazoles and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]
(
d, J ꢀ=ꢀ 8.8 Hz, 1H), 7.64 (m, 9H), 7.35 (m, 4H), 7.26 (d, J ꢀ=ꢀ 8.3 Hz, 1H), J ꢀ=ꢀ 2.6 Hz, 2H), 7.69 (br, 2H), 7.56 (br, 2H), 7.23 (br, 2H), 1.63 (s, 6H);
2
1
3
7
.18 (d, J ꢀ=ꢀ 4.8 Hz, 1H), 7.11 (d, J ꢀ=ꢀ 8.4 Hz, 1H), 6.76 (s, 1H), 2.01 (t, J ꢀ=ꢀ
6.6 Hz, 4H), 1.10 (m,12H), 0.79 (t, J ꢀ=ꢀ 7.5 Hz, 6H), 0.64-0.73 (m, 4H); 126.4, 121.6, 121.3, 79.7, 79.4, 79.1, 47.3, 27.3; λabs (CH Cl ) 360 nm, λ
abs
C-NMR (DMSO-d ): δ 155.1, 151.4, 142.0, 139.0, 138.4, 129.4, 127.6, 127.4,
6
1
2
2
1
3
C-NMR (CDCl ): δ 151.6, 151.0, 148.0, 147.0, 147.2, 141.4, 140.4, 137.7, (MeOH) 348 nm; λem (CH Cl ) 457 nm, λ (MeOH) 401 nm and 426 nm,
3
2
2
em
+
1
1
2
36.4, 132.2, 130.2, 129.7, 129.0, 128.3, 127.3, 126.8, 124.6, 123.4, 123.2, λem (film) 462 nm. HR-MS. Calcd for C H N ([M + H] ): m/z 579.2548.
41 30 4
23.2, 122.9, 120.3, 120.1, 119.8, 119.4, 110.1, 55.1, 40.4, 31.4, 29.7, 29.7, Found: m/z 579.2530.
3.7, 22.6, 14.0; λabs (CH Cl ) 376 nm, λ (MeOH) 364 nm; λem (CH Cl )
2
2
abs
2
2
4
57 nm, λem (MeOH) 421nm and 442 nm, λ (film) 450 nm. HR-MS. 2,2′-[(9,9-Dimethyl-9H-fluorene-2,7-diyl)bis(4,1-phenylene)]
em
+
Calcd for C H N S ([M+H] ): m/z 609.3303. Found: m/z 609.3295.
bis(1-phenyl-1H-benz[d]imidazole) (14b)ꢁThis compound was
42
42
2
1
obtained from 7 and 10b; white solid; yield 75%; mp 318–32°C; H-
NMR (CDCl ): δ 7.94 (d, J ꢀ=ꢀ 8.3 Hz, 2H), 7.80 (d, J ꢀ=ꢀ 8.4 Hz, 2H), 7.51-7.72
3
1
3
(
m, 19H), 7.39 (m, 6H), 7.30 (m, 3H), 1.58 (s, 6H); C-NMR (CDCl ): δ
3
General procedure for synthesis of 14a–16b
1
1
54.6, 152.0, 142.8, 142.3, 139.3, 138.4, 137.3, 137.0, 130.0, 129.9, 129.8,
28.6, 128.5, 127.5, 126.9, 126.2, 123.4, 123.1, 121.2, 120.5, 119.7, 110.4, 47.1,
To a mixture of an aldehyde 7-9 (0.7 mmol), a benzene-1,2-diamine 2 7. 3 ; λabs (CH Cl ) 360 nm, λ (MeOH) 340 nm; λem (CH Cl ) 493 nm,
2
2
abs
2
2
1
0a-c (1.0 mmol), and TsOH (0.1 mmol), was added dioxane (7 mL) at λem (MeOH) 402 nm and 425 nm, λ (film) 450 nm. HR-MS. Calcd for
em
+
room temperature. The mixture was heated under reflux for 9 h, then C H N ([M + H] ): m/z 731.3174. Found: m/z 713.3169.
53
38
4
concentrated under reduced pressure, and the residue was purified
by column chromatography on silica gel using ethyl acetate (16%- 2,2′-[(9,9-Dimethyl-9H-fluorene-2,7-diyl)bis(4,1-phenylene)]
2
0%)/petroleum ether as eluent to afford the final product.
bis(1-(4-methoxyphenyl)-1H-benz[d]imidazole) (14c)ꢁThis com-
pound was obtained from 7 and 10c; white solid; yield 70%; mp 294–
1
2
,2′-[(9,9-Dimethyl-9H-fluorene-2,7-diyl)bis(4,1-phenylene)] 296°C; H-NMR (CDCl ): δ 7.92 (d, J ꢀ=ꢀ 7.2 Hz, 2H), 7.81 (d, J ꢀ=ꢀ 8.3 Hz, 2H),
3
bis(1H-benz[d]imidazole) (14a)ꢁThis compound was obtained 7.73 (d, J ꢀ=ꢀ 8.5 Hz, 4H), 7.64 (m, 8H), 7.23-7.39 (m, 10H), 7.07 (d, J ꢀ=ꢀ 9.4
1
13
from 7 and 10a; yellow solid; yield 65%; mp ꢀ>ꢀ 400°C; H-NMR Hz, 4H), 3.92 (s, 6H), 1.59 (s, 6H); C-NMR (CDCl ): δ 159.6, 154.6, 152.1,
3
(
DMSO-d ): δ 8.31 (d, J ꢀ=ꢀ 9.5 Hz, 4H), 8.04 (m,8H), 7.82 (dd, J ꢀ=ꢀ 1.4 Hz, 142.2, 139.3, 138.4, 137.7, 129.8, 129.6, 128.6, 126.9, 126.2, 123.3, 123.0,
6 1
Table 2ꢀCrystal data and structure refinement for 11b and 13b.
ꢁ
ꢂꢂb
ꢁ
ꢂꢃb
Empirical formula
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
CꢇꢇHꢇꢋNꢈ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
CꢇꢈHꢇꢇNꢈS
ꢋꢄ8.8ꢆ
Formula weight
ꢋꢄꢈ.83
Temperature
Wavelength
Crystal system, space group
ꢈꢉꢋ(ꢈ) K
ꢈꢉꢋ(ꢈ) K
ꢄ.ꢅꢊꢄꢅ3 Å
Triclinic, Pꢊ
8.8ꢇꢉ(ꢈ)
ꢊꢊ.8ꢅꢈ(3)
ꢊꢅ.ꢆ88(ꢇ)
ꢊꢄꢊ.ꢈ3ꢈ(ꢅ)
ꢉꢄ.38ꢇ(ꢅ)
ꢊꢄꢈ.ꢋꢇꢄ(ꢋ)
ꢊꢅꢋꢋ.ꢄ(ꢅ)
ꢈ
ꢄ.ꢅꢊꢄꢅ3 Å
Triclinic, Pꢊ
8.8ꢊꢉꢋ(ꢊꢈ)
̅
̅
a (Å)
b (Å)
c (Å)
α (°)
β (°)
γ (°)
ꢊꢊ.3ꢆꢅꢇ(ꢊꢇ)
ꢊ8.33ꢈ(ꢈ)
ꢅꢉ.ꢄꢄꢈ(3)
8ꢆ.3ꢇꢄ(3)
8ꢆ.ꢈꢆꢅ(ꢇ)
ꢊꢅꢉꢈ.3(ꢇ)
ꢈ
3
Volume (Å )
Z
3
Density (calc.) (mg/m )
ꢊ.ꢊꢊꢅ
ꢊ.ꢊꢇꢆ
-ꢊ
Absorption coefficient (mm )
F (ꢄꢄꢄ)
ꢄ.ꢄꢋꢇ
ꢄ.ꢊꢈꢈ
ꢋꢇ8
ꢋꢆꢈ
Crystal size (mm)
ꢄ.ꢊꢅꢆ ꢃ×ꢃ ꢄ.ꢊꢆ8 ꢃ×ꢃ ꢄ.ꢄꢅꢉ
ꢊ.83ꢊ–ꢈꢆ.ꢄꢇꢉ
ꢄ.ꢈꢊꢊ ꢃ×ꢃ ꢄ.ꢄ8ꢉ ꢃ×ꢃ ꢄ.ꢄꢅꢋ
ꢊ.ꢅꢉꢆ–ꢈꢆ.ꢇꢉꢆ
θ range for data collection (°)
Limiting indices
-ꢊꢄ ꢃꢃ≤ꢃꢃ h ꢃꢃ≤ꢃꢃ ꢊꢄ, -ꢊꢊ ꢃꢃ≤ꢃꢃ k ꢃꢃ≤ꢃꢃ ꢊ3, -ꢈꢊ ꢃꢃ≤ꢃꢃ l ꢃꢃ≤ꢃꢃ ꢈꢊꢃ
ꢊꢄꢊꢆꢅ/ꢋꢈꢉꢋ [R(int) ꢃ=ꢃ ꢄ.ꢄ3ꢉꢅ]
ꢉꢅ.ꢆ%
Semi-empirical from equivalents
ꢄ.ꢅꢇꢆꢅ and ꢄ.ꢋꢆ8ꢄ
Full-matrix least-squares on F
-ꢊꢄ ꢃꢃ≤ꢃꢃ h ꢃꢃ≤ꢃꢃ ꢊꢄ, -ꢊꢇ ꢃꢃ≤ꢃꢃ k ꢃꢃ≤ꢃꢃ ꢊꢄ, -ꢊ8 ꢃꢃ≤ꢃꢃ l ꢃꢃ≤ꢃꢃ ꢈꢊ
ꢊꢄꢇꢊꢄ/ꢋꢆꢇꢉ [R(int) ꢃ=ꢃ ꢄ.ꢄ3ꢉꢆ]
ꢉꢉ.8%
Semi-empirical from equivalents
ꢄ.ꢅꢇꢆꢅ and ꢄ.ꢋꢄꢊꢆ
Full-matrix least-squares on F
Reflections collected/unique
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
Completeness to theta ꢃ=ꢃ ꢈꢆ.ꢄꢆ ꢃ
Absorption correction
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
Max. and min. transmission
Refinement method
2
2
Data/restraints/parameters
Goodness-of-fit on F
ꢋ33ꢊ/8ꢉ/ꢇ83
ꢊ.ꢄ38
ꢋꢆꢇꢉ/ꢉ8/ꢇꢋꢆ
ꢄ.ꢉꢉꢋ
2
Final R indices [I ꢃ>ꢃ ꢈσ (I)]
R indices (all data)
R ꢃ=ꢃ ꢄ.ꢄ8ꢆ3, wR ꢃ=ꢃ ꢄ.ꢈꢊ88
R ꢃ=ꢃ ꢄ.ꢄꢋꢉꢊ, wR ꢃ=ꢃ ꢄ.ꢊꢋꢉꢉ
1
2
1
2
R ꢃ=ꢃ ꢄ.ꢊꢆꢋꢉ, wR ꢃ=ꢃ ꢄ.ꢈꢆꢇ8
R ꢃ=ꢃ ꢄ.ꢊꢈꢉꢄ, wR ꢃ=ꢃ ꢄ.ꢈꢄ3ꢄ
1
2
1
2
Absolute structure parameter -
ꢄ.ꢄꢄꢇ(ꢈ)
ꢄ.ꢄꢄ8(ꢇ)
3
Largest diff. peak and hole (eÅ )ꢃ
ꢄ.ꢈꢅꢆ and -ꢄ.ꢈꢇ3
ꢄ.38ꢄ and -ꢄ.ꢈꢊꢉ
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Q.-F. Li et al.: 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazoles and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]ꢂꢁꢀꢀꢀꢂ9
1
21.2, 120.5, 119.7, 115.1, 110.4, 55.5, 29.7, 27.3; λabs (CH Cl ) 350 nm, λ
abs
at 296 (2) K. The structure was solved by direct methods and refined
2
2
by full-matrix least-squares method on Fobs2 using the SHELXTL 97
(
MeOH) 346 nm; λem (CH Cl ) 463 nm, λ (MeOH) 402,425 nm, λ
2 2 em em
+
(
film) 452 nm. HR-MS. Calcd for C H N O ([M + H] ): m/z 791.3386. sof ware package. The non-hydrogen atoms were refined anisotrop-
55 42 4 2
Found: m/z 791.3346.
ically. The hydrogen atoms bound to carbon were located by using
geometrical calculations, with their position and thermal param-
2
,2′-[(9,9-Dimethyl-9H-fluorene-2,7-diyl)bis(furan-5,2-diyl)] eters being fixed during the structure refinement. A summary of the
bis(1H-benz[d]imidazole) (15a)ꢁThis compound was obtained crystallographic data and structure refinement details are given in
1
from 8 and 10a; yellow-brown solid; yield 68%; mp ꢀ>ꢀ 400°C; H-NMR Table 2.
(
CDCl ): δ 8.16 (s, 2H), 8.00 (q, J ꢀ=ꢀ 27.7 Hz, 4H), 7.63 (br, 4H), 7.37 (d, J ꢀ=ꢀ
3
1
3
3
.3 Hz, 2H), 7.30 (d, J ꢀ=ꢀ 3.3 Hz), 7.23 (q, J ꢀ=ꢀ 9.3 Hz, 4H), 1.63 (s, 6H); C-
Acknowledgments: The authors are grateful for sup-
ports from the National Natural Science Foundation of
China (Project No. 81202402 and 21272154). The authors
also thank Drs. H. Deng and M. Shao, The Instrumental
Analysis & Research Center of Shanghai University, for
structural analysis.
NMR (CDCl ): δ 155.1, 154.9, 145.3, 144.0, 138.5, 129.3, 121.4, 118.8, 113.3,
3
1
4
08.8, 47.2, 27.3; λabs (CH Cl ) 394 nm, λ (MeOH) 390 nm; λem (CH Cl )
2
2
a
b
s
2
2
63 nm, λem(MeOH) 403 nm and 425 nm, λ (film) 427 nm. HR-MS.
em
+
Calcd for C H N O ([M + H] ): m/z 559.2134. Found: m/z 559.2119.
37
26
4
2
2
,2′-[(9,9-Dimethyl-9H-fluorene-2,7-diyl)bis(furan-5,2-diyl)]
bis(1-phenyl-1H-benz[d]imidazole) (15b)ꢁThis compound was
obtained from 8 and 10b; brown solid; yield 67%; mp 242–250°C;
1
H-NMR (DMSO-d ): δ 7.90 (d, J ꢀ=ꢀ 9.3 Hz, 2H), 7.72 (m, 6H), 7.64 (d, J ꢀ=ꢀ
6
8
6
.5 Hz, 2H), 7.55 (m, 4H), 7.26–7.43 (m, 8H), 7.15 (d, J ꢀ=ꢀ 8.4 Hz, 2H),
References
1
3
.93 (d, J ꢀ=ꢀ 4.2 Hz, 2H), 6.76 (d, J ꢀ=ꢀ 3.1 Hz, 2H), 1.51 (s, 6H); C-NMR
(
DMSO-d ): δ 155.9, 154.4, 144.1, 142.9, 138.5, 137.0, 129.8, 129.3, 128.8,
6
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b
s
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[
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,2′-[(9,9-Dimethyl-9H-fluorene-2,7-diyl)bis(thiophene-5,2-diyl)]
[
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DMSO-d ): δ 7.99 (d, J ꢀ=ꢀ 1.5 Hz, 2H), 7.96 (d, J ꢀ=ꢀ 8.8 Hz,2H), 7.87 (d,
6
[
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1
2
13
Hz, 2H), 7.59 (br, 4H), 7.22 (s, 4H), 1.59 (s, 6H); C-NMR (DMSO-d ): δ
6
1
55.1, 147.2, 146.3, 138.5, 133.0, 128.2, 125.2, 121.3, 120.4, 47.3, 29.4, 27.2;
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1
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