Novel anthracene-based cylindrical macrotricyclic polyether: Powerful host for bispyridinium dications

Article abstract of DOI:10.1021/ol100589u

A novel anthracene-based cylindrical macrotricyclic polyether containing two dibenzo-30-crown-10 cavities has been synthesized and shown to be a powerful host to form 1:1 stable complexes with the rodlike bispyridinium dications (K_a > 10⁵ M^-1). Moreover, it was found that the complexes could all self-assemble into linear supramolecular arrays and further 2D mosaic-like architectures in the solid state.

Full text of DOI:10.1021/ol100589u

ORGANIC
LETTERS
2010
Vol. 12, No. 8
1888-1891
Novel Anthracene-Based Cylindrical
Macrotricyclic Polyether: Powerful Host
for Bispyridinium Dications
Yong-Sheng Su†,‡ and Chuan-Feng Chen*,†
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of
Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of
Sciences, Beijing 100190, China, and Graduate School, Chinese Academy of Sciences,
Beijing 100049, China
cchen@iccas.ac.cn
Received March 11, 2010
ABSTRACT
A novel anthracene-based cylindrical macrotricyclic polyether containing two dibenzo-30-crown-10 cavities has been synthesized and shown
to be a powerful host to form 1:1 stable complexes with the rodlike bispyridinium dications (Ka > 105 M-1). Moreover, it was found that the
complexes could all self-assemble into linear supramolecular arrays and further 2D mosaic-like architectures in the solid state.
Since Pedersen1 first reported the synthesis and cation
complexation properties of the crown ethers, host-guest
chemistry2 has attracted great interest during the past 40
years. One particular interest in this regard came from the
paraquat derivatives (N,N′-dialkyl-4,4′-bipyridinium salts)
that have been widely used as guests to construct numerous
complexes with large crown ethers, such as bis(m-phe-
nylene)-32-crown-10 derivatives,3 and bis(p-phenylene)-34-
crown-10 derivatives.4 Comparably, host-guest systems
based on the recognition motif of dibenzo-30-crown-10
derivatives to paraquat derivatives have still been scarcely
investigated.5
Cylindrical macrotricyclic polyethers6 consist of one
central cavity and two lateral circular cavities, which have
new topological features with respect to the macromono- and
(4) (a) Allwood, B. L.; Spencer, N.; Shahriari-Zavareh, H.; Stoddart,
J. F.; Williams, D. J. J. Chem. Soc., Chem. Commun. 1987, 1064–1066.
† Institute of Chemistry, Chinese Academy of Sciences.
(b) Li, Q.; Zhang, W.; Miljan´ı, O.S.; Sue, C.-H.; Zhao, Y.-L.; Liu, L.;
ˇ
‡ Graduate School, Chinese Academy of Sciences.
Knobler, C. B.; Stoddart, J. F.; Yaghi, O. M. Science 2009, 325, 855–859.
(c) Wang, F.; Han, C.; He, C.; Zhou, Q.; Zhang, J.; Wang, C.; Li, N.; Huang,
F. J. Am. Chem. Soc. 2008, 130, 11254–11255. (d) Lu, L.-G.; Li, G.-K.;
Peng, X.-X.; Chen, C.-F.; Huang, Z.-T. Tetrahedron Lett. 2006, 47, 6021–
6025. (e) Feng, D.-J.; Li, X.-Q.; Wang, X.-Z.; Jiang, X.-K.; Li, Z.-T.
Tetrahedron 2004, 60, 6137–6144. (f) Lestini, E.; Nikitin, K.; Mu¨ller-Bunz,
H.; Fitzmaurice, D. Chem.sEur. J. 2008, 14, 1095–1106. (g) Jiang, Y.;
Cao, J.; Zhao, J.-M.; Xiang, J.-F.; Chen, C.-F. J. Org. Chem. 2010, 75,
1767–1770.
(1) (a) Pedersen, C. J. J. Am. Chem. Soc. 1967, 89, 2495–2496. (b)
Pedersen, C. J. J. Am. Chem. Soc. 1967, 89, 7017–7036.
(2) (a) Cram, D. J.; Cram, J. M. Container Molecules and Their Guests;
Royal Society of Chemistry: Cambridge, UK, 1994. (b) Lehn, J.-M.
Supramolecular Chemistry; VCH Publishers: New York, 1995.
(3) (a) Allwood, B. L.; Shahriari-Zavareh, H.; Stoddart, J. F.; Williams,
D. J. J. Chem. Soc., Chem. Commun. 1987, 1058–1061. (b) Huang, F.;
Jones, J. W.; Slebodnick, C.; Gibson, H. W. J. Am. Chem. Soc. 2003, 125,
14458–14464. (c) Huang, F.; Gibson, H. W.; Bryant, W. S.; Nagvekar, D. S.;
Fronczek, F. R. J. Am. Chem. Soc. 2003, 125, 9367–9371. (d) Zhu, K.; Li,
S.; Wang, F.; Huang, F. J. Org. Chem. 2009, 74, 1322–1328. (e) Bryant,
W. S.; Jones, J. W.; Mason, P. E.; Guzei, I.; Rheingold, A. L.; Fronczek,
F. R.; Nagvekar, D. S.; Gibson, H. W. Org. Lett. 1999, 1, 1001–1004.
(5) (a) He, C.; Shi, Z.; Zhou, Q.; Li, S.; Li, N.; Huang, F. J. Org. Chem.
2008, 73, 5872–5880. (b) Pederson, A. M.-P.; Ward, E. M.; Schoonover,
D. V.; Slebodnick, C.; Gibson, H. W. J. Org. Chem. 2008, 73, 9094–9101.
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10.1021/ol100589u  2010 American Chemical Society
Published on Web 03/25/2010

macrobicyclic ligands. The first cylindrical host for paraquat
derivatives was reported by Gibson’s group7 in 2005.
Recently, we8 have synthesized a novel triptycene-based
cylindrical macrotricyclic polyether containing two dibenzo-
24-crown-8 cavities and found that it could also be a highly
efficient host for complexation with different functional
paraquat derivatives in different modes. Herein, we report
synthesis of a novel cylindrical macrotricyclic host containing
two anthracene units as skeleton and two dibenzo-30-crown-
10 cavities 1 (Figure 1), which shows to be a powerful host
were mixed in a 1:1 chloroform/acetonitrile solution, a bright
red solution formed immediately due to the charge-transfer
interaction between the electron-rich aromatic rings of host
1 and the electron-poor pyridinium rings of guest 2. Complex
studies of host 1 with the bispyridinium dications were
1
further carried out in a 1:1 CDCl3/CD3CN solution by H
NMR spectroscopy. As shown in Figure 2, when 1.0 equiv
1
Figure 2
.
Partial H NMR spectra (300 MHz, CD3CN/CDCl3 )
1:1, 295 K) of (a) free host 1, (b) free guest 2, and (c) 1 and 1.0
equiv of 2. [1]0 ) 4.0 mM.
Figure 1. Structure and proton designations of the host 1 and guests
2-4.
of guest 2 was added to a solution of host 1, only one set of
resonances for complex 1·2 was observed. If either the host
or the guest was in excess, the spectrum showed one set of
resonances for host 1 or guest 2 besides those for the
complex.9 These observations suggested that host 1 and guest
2 formed a 1:1 stable complex 1·2, and the rates of the
complexation and decomplexation were both slow. Moreover,
we found that the protons Ha and Hb of guest 2 shifted
significantly upfield, which was attributed to the strong
shielding effect of the aromatic rings of 1. Meanwhile, the
methyl proton of guest 2 also showed considerable upfield
shift (∆δ ) 1.0 ppm). These results are contrary to those of
guest 2 in its complexation with the triptycene-based
analogue,8a which could be explained by the extension of
the aromatic skeleton of 1 placing the methyl protons of 2
in the strong shielding region of the aromatic rings of the
host. A similar effect also resulted in the downfield shift of
proton H1 of host 1. With diquat as the reference guest, the
association constant (Ka1·2)9 for the 1:1 complex 1·2 was
determined by a competitive method10 to be 3.1 × 105 M-1.
Similar to the case of 1·2, complexes 1·3 and 1·4 also
showed typical charge transfer features with the mixed
solutions of bright red and yellow color, respectively. Owing
to the strong shielding effect of the aromatic rings of 1,
significant upfield shifts of the aromatic protons for both 1·3
and 1·4 were observed. However, the N-methyl protons of
guests 3 and 4 shifted downfield, and proton H1 of host 1
shifted to the upfield, which are similar to the cases of the
triptycene-based analogue8a but contrary to those of complex
for the formation of 1:1 stable complexes with different sizes
of rodlike bispyridinium dications. Interestingly, it is also
found that the complexes can all self-assemble into linear
supramolecular arrays, and further 2D mosaic-like architec-
tures in the solid state due to the planar skeleton and high
symmetry of the host in the complexes.
Synthesis of host 1 is depicted in Scheme 1. Reaction of
9,10-dimethyl-2,3,6,7-tetrahydroxyanthracene 5 with com-
Scheme 1. Synthesis of Host 1
pound 6 under high dilution conditions in the presence of
cesium carbonate gave 1 in 22% yield. Host 1 was character-
ized by 1H and 13C NMR spectrometry, mass spectrometry,
and elemental analysis.9
We first investigated the complexation between host 1 and
guest 2 in solution. Consequently, when 1 and 2 (4 mM each)
(7) Huang, F.; Zakharov, L. N.; Rheingold, A. L.; Ashraf-Khorassani,
M.; Gibson, H. W. J. Org. Chem. 2005, 70, 809–813.
(8) (a) Zong, Q.-S.; Chen, C.-F. Org. Lett. 2006, 8, 211–214. (b) Zhao,
J.-M.; Zong, Q.-S.; Han, T.; Xiang, J.-F.; Chen, C.-F. J. Org. Chem. 2008,
73, 6800–6806.
(10) (a) Heath, R. E.; Dykes, G. M.; Fish, H.; Smith, D. K. Chem.sEur.
J. 2003, 9, 850–855. (b) Huang, F.; Switek, K. A.; Zakharov, L. N.;
Fronczek, F. R.; Slebodnick, C.; Lam, M.; Golen, J. A.; Bryant, W. S.;
Mason, P. E.; Rheingold, A. L.; Ashraf-Khorassani, M.; Gibson, H. W. J.
Org. Chem. 2005, 70, 3231–3241.
(9) See the Supporting Informationfor details.
Org. Lett., Vol. 12, No. 8, 2010
1889

1·2. These results could be attributed to the extension of the
guests which place the N-methyl protons in different chemi-
cal environments compared with the complex 1·2. Moreover,
it was found that the complexes 1·3 and 1·4 also showed
slow rates of the complexation and decomplexation at room
temperature. Consequently, the association constants for the
the two pyridinium rings were well coplanar and parallel
with the anthracene rings of 1. These structural features of
complex 1·2 were quite different from those of the paraquat-
based complexes reported previously. We further found that
there existed not only two pairs of C-H···O hydrogen bonds
between the protons of N-methyl groups and the ether oxygen
atoms with the distances of 2.58 (a) and 2.64 Å (b),
respectively, but also a pair of face-face π-stacking interac-
tions between the pyridinium rings of the guest and the
aromatic rings of the host (dπ-π ) 3.37 Å for d). Moreover,
a pair of C-H· ··π interactions between the protons of
N-methyl groups and the aromatic rings of the host with the
distance of 2.80 Å (c) were also observed. These multiple
noncovalent interactions played an important role in forma-
tion of the stable complex, which is consistent with the result
in solution. Due to the planar skeleton and high symmetry
of the host in the complex, it was also found that by virtue
of three pairs of C-H···π interactions between the methylene
and methyl protons of host 1 and the adjacent anthracene
ring (dC-H· · ·π ) 2.62 for e, 2.75 for f, and 2.74 Å for h), and
a pair of C-H· ··O hydrogen bond between the methylene
proton and the ether oxygen atom of the host with the
distance of 2.65 Å (g), the complex 1·2 could self-assemble
into a linear supramolecular array, which further formed a
2D mosaic-like architecture12 (Figure 3b) by virtue of the
noncovalent interactions between the macrocycle and the
1:1 complexes 1·3 and 1·4 at Ka1·3 ) 1.4 × 106 and Ka·4
)
2.1 × 106 M-1, respectively, were obtained by the competi-
tive method.9
The electrospray ionization mass spectra (ESIMS) pro-
vided more evidence for formation of the stable 1:1
complexes 1·2, 1·3, and 1·4.9 Consequently, the strongest
- 2+
(base) peaks at m/z 679.7 for [1·2-2PF6 ] , 692.7 for [1·3-
- 2+
- 2+
2PF6 ] , and 717.9 for [1·4-2PF6 ] , respectively, were
observed.
Formation of the 1:1 complex between 1 and 2 was further
confirmed by its X-ray crystal structure.11 As shown in Figure
3a, it was found that the guest 2 was included in the central
solvent molecule and PF6 counterions.9
-
We also obtained single crystals of complexes 1·313 and
1·414 by diffusion of isopropyl ether into an equimolar
mixture of the host and the guest in CH3CN/CHCl3 (1:1,
v/v) solution. The crystal structures showed that the rodlike
guests 3 and 4 with considerable length (ca. 12.7 Å for 3
and 15.0 Å for 4) could also be completely included inside
the cavity of the host to form 1:1 complexes in the similar
complexation mode to the complex 1·2. As shown in Figure
4a,b, there existed multiple C-H· · ·O hydrogen bonding
(a ) 2.70, b ) 2.66, c ) 2.66, d ) 2.44, e ) 2.45, and f )
2.62 Å) between the N-methyl protons and the aromatic
proton of guest 3 and the ether oxygen atoms of the host
and also face-face π-stacking interactions between the
pyridinium rings of the guest and the aromatic rings of the
host with distances of 3.28 (g), 3.35 (h), 3.39 (i), and 3.34
Å (j), respectively. Moreover, it was found that complex 1·3
could also stack into a linear supramolecular array by
C-H· ··O hydrogen bonding (2.65 for A, and 2.60 Å for B),
and C-H· ··π interactions (2.78 for C, 2.62 for D, and 2.77
Å for E) between the two adjacent macrocycles, which
Figure 3. (a) Crystal structure of 1·2; the blue lines denote the
nocovalent interactions. (b) 2D mosaic-like sheet; the guests are
shown in blue. Solvent molecules, PF6- counterions, and hydrogen
atoms not involved in the interactions were omitted for clarity.
(12) (a) Ashton, P. R.; Claessens, C. G.; Hayes, W.; Menzer, S.; Stoddart,
J. F.; White, A. J. P.; Williams, D. J. Angew. Chem., Int. Ed. Engl. 1995,
34, 1862–1865. (b) Asakawa, M.; Ashton, P. R.; Brown, C. L.; Fyfe,
M. C. T.; Menzer, S.; Pasini, D.; Scheuer, C.; Spencer, N.; Stoddart, J. F.;
White, A. J. P.; Williams, D. J. Chem.sEur. J. 1997, 3, 1136–1150.
(13) Crystal data for 1·3·3CH3CN·CHCl3·H2O: C85H112F12N5O21P2; Mr
) 1936.09; triclinic, P1; a ) 10.5785(15) Å, b ) 12.5308(17) Å, c )
20.433(4) Å; R ) 97.683(11)°, ꢀ ) 97.630(11)°, γ ) 111.007(7)°; V )
2457.5(6) Å3; Z ) 1; d ) 1.308 g cm-3; T ) 173(2) K; R1 ) 0.1061, wR2
) 0.2293 (all data); R1 ) 0.0885, wR2 ) 0.2157 [I > 2σ(I)].
(14) Crystal data for 1·4·2CH3CN: C86H108F12N4O20P2; Mr ) 1807.70;
triclinic, P-1; a ) 11.732(2) Å, b ) 12.020(2) Å, c ) 18.224(3) Å; R )
79.289(5)°, ꢀ ) 85.127(6)°, γ ) 88.981(6); V ) 2516.1(8) Å3; Z ) 1; d )
1.193 g cm-3; T ) 173(2) K; R1 ) 0.0992, wR2 ) 0.2207 (all data); R1 )
0.0754, wR2 ) 0.2040 [I > 2σ(I)].
cavity of host 1 and the two N-methyl groups pointed to the
two dibenzo-30-crown-10 cavities, respectively. Moreover,
(11) Crystal data for 1·2·3CH3CN·2H2O: C82H111F12N5O22P2; Mr
)
1808.70; monoclinic, C2/c; a ) 28.597(6) Å, b ) 10.465(2) Å, c )
29.068(6) Å; ꢀ ) 95.36(3)°; V ) 8661(3) Å3; Z ) 4; d ) 1.387 g cm-3
;
T ) 173(2) K; R1 ) 0.0718, wR2 ) 0.1662 (all data); R1 ) 0.0650, wR2 )
0.1599 [I > 2σ(I)].
1890
Org. Lett., Vol. 12, No. 8, 2010

and 3.39 Å (l), respectively, were also observed (Figure 4c,d).
These multiple noncovalent interactions play a very important
role in formation of the stable complexes. Similarly, the
complex 1·4 could also stack into a linear supramolecular
array, and further a 2D mosaic-like sheet.9 Moreover, it was
further found that because of same orientation of the
complexed molecules, complex 1·4 could stack more inten-
sively than that of 1·2.
In summary, we have synthesized a novel anthracene-
based cylindrical macrotricyclic polyether containing two
dibenzo-30-crown-10 cavities, which showed to be a power-
ful host for complexation with different sizes of the rodlike
bispyridinium dications. Moreover, it was also found that
the complexes could all self-assemble into linear supramo-
lecular arrays, and further mosaic-like sheets in the solid
state. This new kind of donor-acceptor system could provide
useful building blocks for the construction of supramolecular
assemblies with specific structures and properties,15 which
are in progress in our laboratory.
Acknowledgment. We thank the National Natural Science
Foundation of China (20625206), the Chinese Academy
of Sciences, and the National Basic Research Program
(2007CB808004) of China for financial support.
Figure 4. Top (a) and side (b) view of the crystal structure of 1·3.
Top (c) and side (d) view of the crystal structure of 1·4. The blue
-
lines denote the noncovalent interactions. Solvents, PF6 counter-
Supporting Information Available: Experimental pro-
cedures and characterization data for new compounds.
Characterization data for the complexes 1·2, 1·3, and 1·4.
The X-ray crystallographic files (CIF) for complexes 1·2,
1·3, and 1·4. This material is available free of charge via the
Internet at http://pubs.acs.org.
ions, and hydrogen atoms not involved in the interactions were
omitted for clarity.
further self-assembled into a 2D mosaic-like sheet.9 In the
case of complex 1·4, besides the C-H···O hydrogen bonding
between the N-methyl proton of guest 4 and the ether oxygen
atom of the host with the distance of 2.61 Å (m), two pairs
of face-to-face π-stacking interactions between the aromatic
rings of guest 4 and the host with the distances of 3.34 (k),
OL100589U
(15) (a) Stoddart, J. F. Chem. Soc. ReV. 2009, 38, 1802–1820. (b)
Koshkakaryan, G.; Klivansky, L. M.; Cao, D.; Snauko, M.; Teat, S. J.;
Struppe, J. O.; Liu, Y. J. Am. Chem. Soc. 2009, 131, 2078–2079.
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