Synthesis of Helical Polybinaphthyls

Article abstract of DOI:10.1021/ma0354703

Novel helical polybinaphthyls have been designed and synthesized by using an acid-promoted intramolecular cyclization of arylalkynes. The structures of these polymers are characterized by various spectroscopic methods including NMR, UV, FL, and CD. Becaus

Full text of DOI:10.1021/ma0354703

Macromolecules 2004, 37, 2695-2702
2695
Synthesis of Helical Polybinaphthyls
Hu i-Ch a n g Zh a n g a n d Lin P u *
Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319
Received September 29, 2003; Revised Manuscript Received J anuary 26, 2004
ABSTRACT: Novel helical polybinaphthyls have been designed and synthesized by using an acid-promoted
intramolecular cyclization of arylalkynes. The structures of these polymers are characterized by various
spectroscopic methods including NMR, UV, FL, and CD. Because of the restricted rotation in their repeat
units, these polymers are expected to have a well-defined helical chain structure. The molecular weight
effect on the optical properties of such a polymer was studied. Significantly increased fluorescence
sensitivity toward an amino alcohol quencher over the parent 1,1′-bi-2-naphthol was also observed.
In tr od u ction
The beauty of the helical structures of proteins and
DNAs continues to inspire scientists in many fields.
Design and synthesis of unnatural helical polymers for
applications in areas such as nonlinear optics, molecular
recognition, catalysis, and separation have received ever
growing research attention.1 Examples of synthetic heli-
cal polymers include â-amino acid-based oligopepitides,2a
pyridinyl amide-based double helices,2b polyisocyan-
ates,2c,d polyisocyanides,2e chiral acid-doped polyani-
lines,2f,g polyguanidines,2h polytriphenylmethyl meth-
acrylates,2i chiral polyacetylenes,2j chiral polythio-
phenes,2k,l oligo(m-phenyleneethylene)s,2m oligomeric
aryl amides,2n helicences,2o and more. Most of these
materials have their helicity generated from secondary
interactions such as hydrogen bonds and van der Waals
forces. The inherently stable helical polymers such as
helicences2o are less common. Thus, many of the helical
polymers undergo conformational change as well as
helical reversal easily.
To prepare binaphthyl polymers with propagating
stable main-chain helicity, we propose to synthesize the
novel 1,1′-binaphthyl-based ladder polymers such as 2.
In 2, because the chiral binaphthyl units are connected
with fused benzene rings, it is expected to have a well-
defined helical structure. The 1,1′-binaphthyl units in
2 have a R configuration. An energy-minimized molec-
ular modeling structure (PCSpartan-Pro, semiempirical
AM1) of a segment of the polybinaphthyl is given in
Figure 1 where the R groups of 2 are replaced with H
atoms. As shown by the view along the polymer axis,
this polymer will have a stable helical chain structure
with a helical cavity of ca. 8 Å in diameter. Herein, we
report our synthesis and characterization of this class
of structurally novel helical polybinathyls.
In our laboratory, we have used optically active 1,1′-
binaphthyls to build a family of polymers with inher-
ently stable chiral main chains.3 These materials have
shown interesting properties in areas such as nonlinear
optics, electroluminescence, and asymmetric catalysis.
The chiral binaphthyl units in these polymers are
prepared by using conjugated units such as arylenes,
ethynylenes, and vinylenes to link them through carbon-
carbon single bonds. As indicated in polymer 1,3c the
single bond linkage allows the aromatic rings in the
conjugated units of the polymer to rotate away from the
conjugated planar conformation. As a result, we find
that polymer 1 does not have a propagating helical chain
conformation in solution. The optical rotation and CD
spectrum of this polymer are very close to those of its
monomeric model compound. That is, each unit in the
polymer acts independently without an organized helical
chain structure even though the 1,1′-binaphthyl unit
itself is helical.
Resu lts a n d Discu ssion
Syn th esis of th e 1,1′-Bin a p h th yl P olym er 2 by a
Min or -Gr oove P olym er iza tion . In 1997, Swager and
* Corresponding author. E-mail: lp6n@virginia.edu.
10.1021/ma0354703 CCC: $27.50 © 2004 American Chemical Society
Published on Web 03/23/2004

2696 Zhang and Pu
Macromolecules, Vol. 37, No. 8, 2004
F igu r e 1. Molecular modeling structure of polymer 2. The R groups of 2 are replaced with hydrogen atoms.
Sch em e 1. Sw a ger ’s Acid -Ca ta lyzed Cycliza tion of
Ar yla lk yn es to P olya r om a tic Com p ou n d s
We then applied the Swager method to convert 7 to
the helical polymer 2. Polymer 7 was reacted with CF3-
CO2H in methylene chloride at room temperature dur-
ing which the yellow solution turned dark green in 1 h.
After stirred for ca. 12 h followed by aqueous work up,
polymer 2 was obtained. Purification by precipitation
with hexane from methylene chloride multiple times
gave 2 as a dark brown solid in 95% yield. Polymer 2
was completely soluble in common solvents such as
THF, methylene chloride, and chloroform. Because of
its dark color in solution, its specific optical rotation
fluctuated at around -531 (c ) 0.1, CH2Cl2), the
opposite sign of that of polymer 7 with greatly increased
value. GPC showed its molecular weight as Mw ) 17 900
and Mn ) 10 500 (PDI ) 1.70).
Syn th esis of th e 1,1′-Bin a p h th yl P olym er s 10
a n d 13 by th e Ma jor -Gr oove P olym er iza tion . An-
other 1,1′-binaphthyl monomer 8 was also synthesized.
The Suzuki coupling of 8 with 6 led to polymerization
at the major groove of the binaphthyl unit to generate
polymer 9 (Scheme 3). The molecular weight of this
polymer as measured by GPC was Mw ) 14 300 and Mn
) 8700 (PDI ) 1.64). Its specific optical rotation was
[R]D ) -115.7 (c ) 0.1, CH2Cl2). Treatment of this
polymer with CF3CO2H in methylene chloride at room
temperature gave polymer 10 as a dark brown solid in
97% yield. This polymer was soluble in common organic
solvents. GPC analysis gave its molecular weight as Mw
) 17 400 and Mn ) 10 200 (PDI ) 1.71). The dark color
of the polymer solution gave a fluctuating specific optical
co-workers reported a convenient intramolecular cy-
clization of arylalkynes to fused polyaromatic com-
pounds.4 As the example in Scheme 1 shows, treatment
of 3 with CF3CO2H at room temperature led to a
quantitative formation of the fused polyaromatic com-
pound 4.4 We have used this method to synthesize the
desired helical polybinaphthyls.
Both the optically active binaphthyl compound 55 and
the aryl dibromide 64 are readily prepared in two steps
from the commercially available starting materials
(Scheme 2). A 1,1′-binaphthyl molecule contains a minor
groove and a major groove as indicated in Scheme 2.
The Suzuki coupling6 of 5 and 6 led to the polymeriza-
tion at the minor groove of the 1,1′-binaphthyl monomer
to generate polymer 7. This polymer was soluble in
common organic solvent. Gel permeation chromatogra-
phy (GPC) showed its molecular weight as Mw ) 11 200
and Mn ) 7300 (PDI ) 1.54) relative to polystyrene
standards. The specific optical rotation of 7, [R]D, was
+36.8 (c ) 0.1, CH2Cl2).

Macromolecules, Vol. 37, No. 8, 2004
Helical Polybinaphthyls 2697
Sch em e 2. Syn th esis of th e Min or -Gr oove Helica l P olybin a p h th yl 2
Sch em e 3. Syn th esis of th e Ma jor -Gr oove Helica l P olybin a p h th yl 10
rotation at around [R]D ≈ -708 (c ) 0.1, CH2Cl2), a
the generally more reactive R-positions of the naphthyl
much larger value than that of 9. The intramolecular
cyclization of 9 could occur by the electrophilic attack
on either the R or â positions of the naphthyl rings.
Although at this stage, we are not able to determine
the actual pathway spectroscopically, it is proposed that
rings might have participated to form 10.
Monomer 11 containing a bridging methylene at the
minor groove was prepared. The Suzuki coupling of 11
with 6 gave the major groove polymer 12 (Scheme 4).
This polymer was obtained as a light-yellow solid in 90%

2698 Zhang and Pu
Macromolecules, Vol. 37, No. 8, 2004
Sch em e 4. Syn th esis of th e Ma jor -Gr oove Helica l P olybin a p h th yl 13
yield. GPC gave its molecular weight as Mw ) 38 800
and Mn ) 12 100 (PDI ) 3.22). Its specific optical
rotation was [R]D ) -466.7 (c ) 0.1, CH2Cl2). Treatment
of this polymer with CF3CO2H in methylene chloride
at room temperature gave polymer 13 as a dark brown
solid in 95% yield. This polymer was soluble in common
organic solvents. GPC analysis gave its molecular
weight as Mw ) 29 800 and Mn ) 11 400 (PDI ) 2.61).
Sp ectr oscop ic Stu d y of th e Ch ir a l P olybin a p h -
1
th yls. In the H NMR spectra of polymer 7, the CH3-
OCH2O protons are observed at δ 2.48 (brs, 6 H), and
4.55 (brs, 4H). Its 13C NMR spectrum shows two alkyne
carbon signals at δ 94.69 and 98.49. After treatment of
F igu r e 2. UV spectra of polymers 2 and 7 in methylene
chloride.
1
7 with CF3CO2H, the H and 13C NMR spectra of the
resulting polymer 2 show the disappearance of both the
CH3OCH2O groups and the alkyne carbons. The same
is observed in the conversion of 9 to 10. That is, both
the intramolecular cyclization and deprotection took
place under the acidic condition. However, in the
The optical properties of these polymers were studied.
Figure 2 compares the UV spectrum of polymer 7 with
that of 2. It shows new absorptions at the long wave-
length between 390 and 560 nm after polymer 7 is
converted to 2. In the fluorescence spectra, a very large
red shift (∆λ ) 123 nm) is observed going from 7 to 2
(Figure 3). The large red shifts observed for the absorp-
tion and emission of polymer 2 indicate a greatly
increased conjugation in this polymer. These observa-
tions are similar to what was observed by Swager in
the conversion of 3 to 4 (see Scheme 1). Large red shifts
in the UV and fluorescence spectra are also observed
from polymers 9 and 12 to polymers 10 and 13,
1
reaction of 12 with CF3CO2H, the H NMR spectrum of
the resulting polymer 13 showed that the bridging
methylene protons were still present while the alkyne
carbon signals disappeared. The bridging methylene
groups of 13 were found to be very stable toward
hydrolysis. The 13C NMR signals of polymers 2, 10, and
13 are significantly weaker than their precursor poly-
mers because of the much more rigid ladder structures
of their repeating units.

Macromolecules, Vol. 37, No. 8, 2004
Helical Polybinaphthyls 2699
Ta ble 1. Sp ectr a l Da ta of th e P olym er s 7, 2, 9, 10, 12, a n d 13 in Meth ylen e Ch lor id e Solu tion
polymer
UV
λmax (ꢀ) nm
7
2
9
10
12
13
366 (sh, 3.58 × 104) 453 (1.26 × 104)
320 (6.28 × 104)
411 (1.03 × 104 )
372 (sh, 3.47 × 104) 410 (1.28 × 104)
341 (4.86 × 104)
398
344 (7.33 × 104)
281 (5.53 × 104)
339 (6.06 × 104)
315 (7.23 × 104)
268 (5.28 × 104)
408
330 (7.14 × 104)
fluorescence
521
408
450
455
λ
emi (nm)
CD
476 (sh)
484 (sh)
5.86 × 104 (365)
-6.98 × 104 (360) -4.06 × 103 (359) -2.86 × 105 (351) 2.80 × 104 (337)
-2.49 × 105 (350)
6.05 × 104 (324)
-4.76 × 104 (303)
-8.19 × 104 (277)
1.56 × 105 (241)
[θ] (λmax, nm, -1.17 × 105 (292)
1.0 × 10-5 M) 1.90 × 105 (258)
7.49 × 104 (330)
1.23 × 105 (268)
8.07 × 103 (341)
1.62 × 105 (320)
-1.75 × 105 (289)
-1.64 × 105 (284) -3.54 × 103 (273) 3.90 × 104 (252)
F igu r e 4. CD spectra of polymers 9 and 10 in methylene
chloride.
F igu r e 3. Fluorescence spectra of polymers 2 and 7 in
methylene chloride.
respectively. These data are summarized in Table 1.
In our previous studies,3b,d,e we have demonstrated
that the conjugation of the polybinaphthyls is deter-
mined by the nature of their repeating units, and there
is no extended conjugation across the 1,1′-bond of the
binaphthyl units. Therefore, on the basis of both the UV
absorption and fluorescence studies, we conclude that
the acid-promoted intramolecular cycloaromatization
has proceeded smoothly from polymers 7, 9, and 12 to
polymers 2, 10, and 13, respectively, and the resulting
polymers have much better conjugated repeating units
because of the formation of the planar and fused
polyaromatic systems.
Dramatic changes are also observed in the CD spectra
of the chiral polymers after cyclization. The CD spectra
of polymer 9 and 10 are displayed in Figure 4. As shown
in the figure, new positive and negative CD signals
centered at ca. 340 nm, probably due to the exciton
coupling of the helical aromatic units, appeared when
polymer 9 was converted to polymer 10. Large differ-
ences are also observed going from polymers 7 and 12
to polymers 2 and 13, respectively (Table 1).
Effect of th e Molecu la r Weigh t of P olym er 10 on
Its Sp ectr oscop ic P r op er ties. To study how the
molecular weight of the new polymers influences their
optical properties, we have prepared polymer 10 of
various molecular weights by quenching the coupling
of 6 and 8 at 24, 10, 6, and 4 h followed by treating the
isolated polymers with CF3CO2H. This process gave
F igu r e 5. UV spectra of polymers 10a -d .
of the planar polycyclic aromatic repeat units in the
polymer chain at high molecular weights. The fluores-
cence spectra of these polymers demonstrate that there
is almost no change in the emission wavelengths at the
different molecular weights (Figure 6). This indicates
that the emission of the polymers is due to their better
conjugated internal repeating unit, and there is no
emission from the less conjugated terminal units. An
efficient energy transfer from the less conjugated ter-
minal units to the more conjugated internal repeat units
can be proposed.
The CD spectra of these polymers are shown in Figure
7. As the molecular weight increases from polymer 10d
to 10a , there is a large increase for the CD effects
centered at ca. 340 nm. The formation of the planar
conjugated repeat unit in polymer 10 is expected to force
the polymer to adopt a propagating helical chain
structure. The large changes in the CD signals of 10
with respect to the increasing molecular weights indi-
cates the formation of more of the planar polycyclic
polymers 10a (Mn ) 10 200, PDI ) 1.71), 10b (Mn
)
5600, PDI ) 1.38), 10c (Mn ) 4200, PDI ) 1.31), and
10d (Mn ) 3300, PDI ) 1.27).
The UV spectra of these materials show that the
absorbance at the long wavelength region increases with
the increase of the molecular weight of the polymer
(Figure 5). This is consistent with the increased number

2700 Zhang and Pu
Macromolecules, Vol. 37, No. 8, 2004
increased fluorescence sensitivity of the polymer over
BINOL toward the amino alcohol may be due to an
energy migration along the helical conjugated polymer
chain.8 This could also be attributed to the lower π-π*
band gap of the polymer which may facilitate the
photoinduced electron-transfer quenching by the amino
alcohol. We further found that the fluorescence quench-
ing of 2 by the two enantiomers of 14 was different with
an ef (ef ) |I0 - IRS|/|I0 - ISR|, the enantiomeric
fluorescence difference ratio) value of 1.12 ( 0.01.
Although this enantioselectivity is small, it is larger
than using (R)-BINOL, which showed no difference at
all in the fluorescence quenching when treated with the
two enantiomers of 14.
F igu r e 6. Fluorescence spectra of polymers 10a -d .
Su m m a r y
In summary, we have applied the acid-catalyzed
intramolecular cyclization of electron-rich aromatic
alkynes to convert the polybinaphthyls to novel helical
polymers. The UV, fluorescence, and CD spectra support
the formation of polycyclic aromatic repeating units in
these polymers. The molecular weight effect on the
optical properties of such a helical polymer was also
studied. One of the polymers has shown significantly
increased fluorescence sensitivity toward an amino
alcohol quencher over the parent BINOL. Polymers of
such a novel helical and conjugated structure may find
applications in areas such as chiral sensing, polarized
light emission, nonlinear optics, and asymmetric ca-
talysis.
Exp er im en ta l Section
Gen er a l Da t a . Unless otherwise noted, all the reagents
were purchased from Aldrich and used without further puri-
fication. Tetrahydrofuran (THF) and diethyl ether (Et2O) were
distilled from sodium benzophenone ketyl immediately prior
to use. Hexane was distilled over calcium chloride. Toluene
was distilled from sodium, and dichloromethane was distilled
over calcium hydride. Thin-layer chromatography was per-
formed on precoated silica gel plates. Silica gel (70-230 and
230-400 mesh) was used for column chromatography. 4-(Hex-
yloxy)phenylacetylene was purchased from Maybridge Chemi-
cal Co.
F igu r e 7. CD spectra of polymers 10a -d .
The NMR spectra were recorded on a Varian-300 MHz
spectrometer. Mass spectra were recorded either at atmo-
spheric pressure chemical ionization (APCI) or at electrospray
ionization (ESI) mode. Gel permeation chromatography (GPC)
utilized a Waters 510 HPLC pump, a Waters 410 differential
refractometer, and a Ultrastyragel linear GPC column. THF
was used as the eluting solvent in the GPC analysis, and
polystyene standards were used. The UV-vis spectra were
recorded with a Cary 5E UV-vis-NIR spectrophotometer. The
CD spectra were recorded with J ASCO J -720 spectropolarim-
eter. Elemental analyses were performed by Atlantic Microlab,
Inc. High-resolution mass analyses were performed by Uni-
versity of California Riverside Mass Spectrometry Facility.
P r ep a r a tion a n d Ch a r a cter iza tion of 1,4-Dibr om o-2,5-
bis((4-(h exyloxy)p h en yl)eth yn yl)ben zen e, 6. A solution of
4-(hexyloxy)phenylacetylene (3.48 g, 17.2 mmol) in THF (15
mL) was cannulated dropwise into a mixture of 1,4-dibromo-
2,5-diiodobenzene (4.0 g, 8.2 mmol), (PPh3)2PdCl2 (115 mg, 0.16
mmol), CuI (156 mg, 0.82 mmol), (C4H9)4NBr (158 mg, 0.49
mmol), toluene (35 mL), diisopropylamine (35 mL), and THF
(20 mL) at room temperature under nitrogen. The reaction
mixture was stirred for 6 h to afford a gray suspension. After
removal of solvent, the residue was dissolved in CHCl3 (120
mL) and washed with 5% HCl (3 × 30 mL), H2O (30 mL), 5%
NH4OH (3 × 30 mL), and H2O (2 × 30 mL). After concentration
by rotary evaporator to about 50 mL, MeOH was added to
precipitate the compounds out as a light yellow solid. Recrys-
tallization from THF/MeOH gave compound 6 as white granu-
F igu r e 8. Fluorescence spectra of BINOL and polymer 2 with
and without the amino alcohol (R,S)-14.
aromatic repeating units at the high molecular weights.
Stu d y of th e F lu or escen ce Sp ectr u m of th e
Min or Gr oove P olym er 2 in th e P r esen ce of a n
Am in o Alcoh ol. A preliminary study on the use of the
helical polymers for the fluorescent sensing of amino
alcohols was conducted. Previously, it was reported that
the fluorescence of the parent 1,1′-bi-2-naphthol (BINOL)
can be quenched by amines and amino alcohols.7 We
found that polymer 2 was a much more efficient
fluorescent sensor than BINOL when interacting with
an amino alcohol quencher. Figure 8 compares the
fluorescence spectra of (R)-BINOL with that of 2 both
at 1.0 × 10-5 M in CH2Cl2/hexane (1:1) for interaction
with (1R,2S)-(-)-N-methylephedrine (14, 3.0 × 10-2 M).
The I0/I is 1.3 for BINOL but 3.4 for 2. This significantly

Macromolecules, Vol. 37, No. 8, 2004
Helical Polybinaphthyls 2701
1
lar crystals in 80% yield (4.2 g). H NMR (300 MHz, CDCl3):
H), 3.16 (s, 6 H), 3.82 (t, 4H, J ) 6.3 Hz), 5.05 (d, 2H, J ) 6.6
Hz), 5.15 (d, 2H, J ) 6.6 Hz), 6.67 (d, 4H, J ) 9.0 Hz), 7.16 (d,
4H, J ) 9.0 Hz), 7.38 (d, 2H, J ) 8.4 Hz), 7.66 (d, 2H, J ) 9.3
Hz), 7.74 (d, 2H, J ) 8.7 Hz), 7.81 (s, 2H), 8.07 (d, 2H, J ) 9.0
Hz), 8.31 (s, 2H). 13C NMR (125 MHz, CDCl3): δ 13.99, 22.55,
25.68, 29.10, 31.53, 55.88, 67.95, 88.09, 94.36, 95.43, 114.43,
117.76, 121.33, 121.88, 125.09, 128.01, 129.83, 132.77, 133.49,
δ 0.92 (t, 6H, J ) 6.6 Hz), 1.35-1.47 (m, 12H), 1.80 (m, 4H),
3.99 (t, 4H, J ) 6.6 Hz), 6.89 (d, 4H, J ) 8.7 Hz), 7.50 (d, 4H,
J ) 8.7 Hz), 7.75 (s, 2H). 13C NMR (75 MHz, CDCl3): δ 13.99,
22.56, 25.65, 29.08, 31.52, 68.11, 85.78, 96.90, 114.10, 114.61,
123.41, 126.32, 133.29, 135.68, 159.87. ΜS(ΕΙ): m/z (relative
intensity) 636 (M+, 100), 468 (45). HRMS (EI): m/z calcd for
C
34H36Br2O2: 634.1082; found: 634.1094.
P r ep a r a tion a n d Ch a r a cter iza tion of P olym er 7. In
135.31, 141.68, 153.15, 159.28. Anal. Calcd for C58H56O6
H2O: C, 80.40; H, 6.75. Found: C, 80.00; H, 6.47.
+
drybox, THF (6.0 mL) and degassed aqueous K2CO3 (2.0 mL,
1.0 M, 2.0 mmol) were added to a mixture of (R)-5 (188 mg,
0.3 mmol), 6 (191 mg, 0.30 mmol), and Pd(PPh3)4 (21 mg, 0.018
mmol). The reaction mixture was heated at reflux for 90 h.
The solvent was then removed under vacuum, and the residue
was redissovled in CH2Cl2 (30 mL). The solution was washed
with H2O (3 × 30 mL) and brine and dried over Na2SO4. After
filtration and removal of solvent, the sticky residue was
dissolved in a minimum amount of CH2Cl2. The polymer was
precipitated out with the addition of hexane. This procedure
was repeated two more times to afford polymer 7 as an orange
solid in 91% yield (230 mg). [R]D ) +36.8 (c ) 0.1, CH2Cl2).
GPC: Mn ) 7300, Mw ) 11 200 (PDI ) 1.54). 1H NMR (300
MHz, CDCl3): δ 0.88 (br, m, 6H), 1.31 (br, 12H), 1.70 (br, 4H),
2.48 (br, 6H), 3.87 (br, 4H), 4.55 (br, m, 4H), 6.72 (br, 4H),
7.18-7.42 (br, 10H), 7.94 (br, 4H), 8.17 (br, 2H). 13C NMR (75
MHz, CDCl3): δ 13.99, 22.54, 25.63, 29.06, 31.52, 55.80, 67.97,
87.70, 94.69, 98.49, 114.40, 123.08, 125.10, 126.14, 126.53,
127.82, 129.63-134.84 (m), 139.94, 151.79, 159.20. Anal. Calcd
for C58H56O6 + H2O: C, 80.40; H, 6.75. Found: C, 80.71; H,
6.54.
P r ep a r a tion a n d Ch a r a cter iza tion of P olym er 10. The
preparation procedure for polymer 10 was the same as polymer
2 except that polymer 9 was used. Polymer 10 was obtained
as a dark brown solid in 95% yield. [R]D ) -708.4 (c ) 0.1,
CH2Cl2). GPC: Mn ) 10 200, Mw ) 17 400 (PDI ) 1.71). 1H
NMR (300 MHz, CDCl3): δ 0.95-1.87 (br, m, 22 H), 4.10 (br,
m, 4H), 5.16 (br, 2H), 7.11-9.10 (br, m, 20H). 13C NMR (125
MHz, CDCl3): δ 14.08, 22.64, 25.82, 29.34, 31.65, 68.21, 115.1,
122.9-158.5 (m). Anal. Calcd for C54H48O4 + H2O: C, 83.33;
H, 6.48. Found: C, 80.39; H, 6.18.
P r ep a r a tion a n d Ch a r a cter iza tion of Mon om er 11. (a)
(R)-9,14-Dibromo-3,5-dioxacyclohepta[2,1-a;3,4-a′]dinaphtha-
lene (A) was prepared from the reaction of (R)-6,6′-dibromo-
[1,1′]binaphthyl-2,2′-diol with CH2I2 and K2CO3 in DMF.9 (b)
Conversion of A to monomer 11. Under nitrogen, nBuLi (3.0
mL, 2.5 M in hexane, 7.5 mmol) was added to a solution of A
(1.37 g, 3.0 mmol) in THF (50 mL) at -78 °C. After the reaction
mixture was stirred for 6 h at the same temperature, it was
then cannulated dropwise into a solution of 2-isopropoxy-
4,4′,5,5-tetramethyl-1,3,2-dioxaborolane (3.0 mL, 15 mmol) in
THF (20 mL) at -78 °C. The mixture was allowed to warm to
room temperature and stirred overnight. The mixture was
filtered, and the solid was washed with CH2Cl2. The combined
solution was concentrated and then passed through a short
silica gel column with the ethyl acetate as the elute to give a
light-yellow solid. Recrystallization from ether/hexane gave 11
as colorless crystals in 76% yield (1.25 g). 1H NMR (300 MHz,
CDCl3): δ 1.39 (s, 24 H), 5.72 (s, 2 H), 7.44 (d, 2 H, J ) 8.4
P r ep a r a tion a n d Ch a r a cter iza tion of P olym er 2. Un-
der nitrogen, trifluoroacetic acid (0.69 mL, 8.9 mmol) was
added to a solution of polymer 7 (150 mg, 0.18 mmol) in CH2-
Cl2 (20 mL) at room temperature. The color of the solution
changed from yellow to dark green within 1 h. After stirred
for overnight, the solution was washed with 10% NaHCO3 (3
× 20 mL) and H2O (2 × 20 mL) and dried over Na2SO4. After
filtration and removal of solvent, the sticky residue was
dissolved in a minimum amount of CH2Cl2. The polymer was
precipitated out with the addition of hexane. This procedure
was repeated two more times to afford polymer as a dark
brown solid in 95% yield (128 mg). [R]D ) -531.2 (c ) 0.1,
CH2Cl2). GPC: Mn ) 10 500, Mw ) 17 900 (PDI ) 1.70). 1H
NMR (300 MHz, CDCl3) δ 0.92-1.87 (br, m, 22H), 4.09 (br,
4H), 7.06-8.11 (br, m, 20H). 13C NMR (75 MHz, CDCl3): δ
14.03, 22.60, 25.76 (m), 29.30, 31.55, 68.12, 114.97, 122.56-
Hz), 7.48 (d, 2 H, J ) 8.7 Hz), 7.64 (dd, 2H, J 1 ) 8.7 Hz, J 2
)
1.2 Hz), 8.03 (d, 2 H, J ) 8.4 Hz), 8.46 (s, 2H). 13C NMR (75
MHz, CDCl3): δ 24.90, 83.93, 103.16, 120.88, 125.89, 125.99,
130.64, 131.11, 133.78, 136.63, 151.13. MS (APCI): m/z
(relative intensity) 551 (M+ + 1, 100). Anal. Calcd for
C
33H36B2O6: C, 72.03; H, 6.59. Found: C, 71.82; H, 6.63.
P r ep a r a tion a n d Ch a r a cter iza tion of P olym er 12. The
preparation procedure for polymer 12 was the same as polymer
7 except that monomer 11 was used, and the reaction mixture
was refluxed for 24 h under nitrogen. Polymer 12 was obtained
as a light-yellow solid in 90% yield. [R]D ) -466.7 (c ) 0.1,
CH2Cl2). GPC: Mn ) 12 100, Mw ) 38 800 (PDI ) 3.22). 1H
NMR (300 MHz, CDCl3): δ 0.79 (brs, 6 H), 1.17 (brs, 8 H),
1.28 (brs, 4 H), 1.61 (brs, 4 H), 3.78 (brs, 4H), 5.80 (brs, 2H),
6.69 (d, 4H, J ) 6.9 Hz), 7.23 (d, 4H, J ) 7.8 Hz), 7.57 (m,
2H), 7.70-7.90 (m, 6H), 8.10 (m, 2H), 8.35 (brs, 2H). 13C NMR
(125 MHz, CDCl3): δ 13.96, 22.50, 25.64, 29.09, 31.48, 67.92,
87.78, 94.65, 103.29, 114.51, 114.72, 121.36, 121.98, 126.12,
126.46, 127.71, 128.82, 130.77, 131.58, 131.81, 132.88, 134.20,
137.76 (br, m), 158.25 (br, m). Anal. Calcd for C54H48O4
H2O: C, 83.33; H, 6.48. Found: C, 81.67; H, 6.17.
+
P r ep a r a tion a n d Ch a r a cter iza tion of Mon om er 8.
Under nitrogen, nBuLi (6.25 mL, 1.6 M in hexane, 10 mmol)
was added to a solution of (R)-6,6′-dibromo-2,2′-bis(meth-
oxymethoxy)-[1,1′]binaphthalenyl (2.17 g, 4.0 mmol) in THF
(40 mL) at -78 °C. After the reaction mixture was stirred for
6 h at the same temperature, it was then cannulated dropwise
into a solution of 2-isopropoxy-4,4′,5,5-tetramethyl-1,3,2-diox-
aborolane (4.0 mL, 20 mmol) in THF (20 mL) at -78 °C. The
mixture was allowed to warm to room temperature and stirred
overnight. The mixture was filtered, and the solid was washed
with CH2Cl2. The combined solution was concentrated. The
residue was purified by column chromatography on silica gel
136.38, 141.50, 151.65, 159.40. Anal. Calcd for C55H48O4
H2O: C, 83.58; H, 6.38. Found: C, 83.86; H, 6.19.
+
P r ep a r a tion a n d Ch a r a cter iza tion of P olym er 13. The
preparation procedure for polymer 13 was the same as polymer
2 except that polymer 12 was used. Polymer 13 was obtained
as a dark brown solid in 95% yield. 1H NMR (300 MHz,
CDCl3): δ 0.90-1.87 (br, m, 22H), 4.10 (br, 4H), 5.72 (br, 2H),
7.20-9.18 (br, m, 20H). 13C NMR (125 MHz, CDCl3): δ 14.11,
22.64, 25.82, 29.34, 31.66, 68.19, 103.3 9w), 114.9-158.4 (br,
m). GPC: Mn ) 11 400, Mw ) 29 800 (PDI ) 2.61). Anal. Calcd
for C55H48O4 + H2O: C, 83.58; H, 6.38. Found: C, 83.04; H,
6.25.
1
to give monomer 8 as a white solid in 47% yield (1.21 g). H
NMR (300 MHz, CDCl3): δ 1.36 (s, 24 H), 3.14 (s, 6H), 4.97
(dd, 2 H, J 1 ) 3.9 Hz, J 2 ) 0.6 Hz), 5.07 (dd, 2 H, J 1 ) 3.9 Hz,
J 2 ) 0.6 Hz), 7.10 (d, 2 H, J ) 5.1 Hz), 7.56 (m, 4 H), 8.00 (d,
2 H, J ) 5.4 Hz), 8.40 (s, 2H). 13C NMR (125 MHz, CDCl3): δ
24.90, 55.83, 83.74, 94.91, 116.89, 120.86, 124.54, 129.17,
130.26, 130.83, 135.70, 136.37, 153.55. Anal. Calcd for
C
36H44B2O8: C, 69.03; H, 7.08. Found: C, 68.96; H, 7.30.
P r ep a r a tion a n d Ch a r a cter iza tion of P olym er 9. The
F lu or escen ce Mea su r em en t for th e In ter a ction of 2
a n d (R)-BINOL w ith th e Am in o Alcoh ol N-Meth ylep h e-
d r in e, 14. Spectroscopic grade CH2Cl2 and hexane were used.
The CH2Cl2 stock solutions of polymer 2 (1.9 mg/25 mL, 1.0 ×
10-4 M), (1R,2S)-(-)-14 (53.8 mg/10 mL, 0.30 M), and (R)-
BINOL (2.9 mg/100 mL, 1.0 × 10-4 M) were prepared. In a 10
mL volumetric flask, 1 mL of the stock solution of polymer 2
preparation procedure for polymer 9 was the same as polymer
7 except that monomer 8 was used, and the reaction mixture
was refluxed for 24 h under nitrogen. Polymer 9 was obtained
as an orange solid in 97% yield. [R]D ) -115.7 (c ) 0.1, CH2-
Cl2). GPC: Mn ) 8700, Mw ) 14 300 (PDI ) 1.64). 1H NMR
(300 MHz, CDCl3): δ 0.82 (m, 6 H), 1.31 (m, 12 H), 1.68 (m, 4

2702 Zhang and Pu
Macromolecules, Vol. 37, No. 8, 2004
E. E.; Bouman, M. M.; Meijer, E. W.; Pomp, A.; Simenon, M.
M. J . Synth. Met. 1994, 66, 93-97. (h) Schlitzer, D. S.; Novak,
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was diluted with CH2Cl2/hexane (1:1) to 10 mL. The fluores-
cence spectrum of the resulting solution of 2 (1.0 × 10-5 M)
gave λemi ) 519 nm (λexc ) 355 nm). Similarly, in a 10 mL
volumetric flask, 1 mL of the stock solution of polymer 2 was
mixed with 1 mL of the stock solution of (1R,2S)-(-)-N-
methylephedrine, which was then diluted with CH2Cl2/hexane
(1:1) to 10 mL for fluorescence measurement. In the same way,
the interaction of (R)-BINOL with the amino alcohol was
studied. For (R)-BINOL, the λexc and λemi are 280 and 364 nm,
respectively.
Ack n ow led gm en t. Partial support of this work
from the Office of Naval Research (N00014-99-1-0531)
and the National Institute of Health (R01GM58454) is
gratefully acknowledged.
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