Novel chiral bis-dipolar 6,6'-disubstituted binaphthol derivatives for second-order nonlinear optics: Synthesis and linear and nonlinear optical properties

Article abstract of DOI:10.1021/ja960076o

A number of thermally and optically stable, bis-dipolar chiral molecules based on two geometries of the binaphthol (BN) system with different acceptors/substituents have been synthesized for the first time, and the synthetic routes are reported: optically

Full text of DOI:10.1021/ja960076o

J. Am. Chem. Soc. 1996, 118, 6841-6852
6841
Novel Chiral Bis-dipolar 6,6′-Disubstituted Binaphthol
Derivatives for Second-Order Nonlinear Optics: Synthesis and
Linear and Nonlinear Optical Properties
H.-J. Deussen,† E. Hendrickx,‡ C. Boutton,‡ D. Krog,† K. Clays,‡ K. Bechgaard,§
A. Persoons,*,‡ and T. Bjørnholm*,†
Contribution from the Centre for Interdisciplinary Studies of Molecular Interactions,
Department of Chemistry, UniVersity of Copenhagen, Symbion, FruebjergVej 3,
DK-2100 Copenhagen Ø, Denmark, Laboratory of Chemical and Biological Dynamics,
Center for Research on Molecular Electronics and Photonics, Celestijnenlaan 200D,
B-3001 HeVerlee, Belgium, and Department of Solid State Physics, Risø National Laboratory,
DK-4000 Roskilde, Denmark
ReceiVed January 10, 1996X
Abstract: A number of thermally and optically stable, bis-dipolar chiral molecules based on two geometries of the
binaphthol (BN) system with different acceptors/substituents have been synthesized for the first time, and the synthetic
routes are reported: optically pure 6,6′-disubstituted 2,2′-diethoxy-1,1′-binaphthyls {R, R′) -Br, -CHO, -CHdC-
(CN)(COOEt), -CHdC(CN)2, -CHdCHCN, -CHdCH(p-NO2Ph)} and optically pure 9,14-disubstituted dinaphtho-
[2,1-d:1′,2′-f][1,3]dioxepins {R, R′ ) -Br, -CHO, -CH)C(CN)(COOEt), -CHdC(CN)2, -CHdCHCN,
-CHdCHSO2CH3, -CHdCHCHO, -CHdCHCHdC(CN)2}. All molecules possess two equal donor-acceptor
systems linked together to give a bis-dipolar system. Two mono-dipolar 6-substituted 2-butoxynaphthalene (R )
-CHdC(CN)2, -CHdC(CN)(COOEt)) donor-acceptor systems were prepared as references. The linear optical
properties including solvatochromic shifts of absorption and fluorescence revealed strong charge transfer excitations
in the new dipolar systems. The molecules show a high first hyperpolarizability â (up to (344-364) × 10-30 esu)
as measured by electric-field-induced second-harmonic generation (EFISHG) and hyper-Rayleigh scattering (HRS).
A model is developed to express the first hyperpolarizability of the bis-dipolar molecules in terms of the molecular
geometry and the â of the monomeric donor-acceptor units. The tensor components were determined experimentally
using this model and data from HRS and EFISHG. These techniques probe different combinations of the components
of the molecular hyperpolarizability tensor. The results obtained are found to be in excellent mutual agreement.
Introduction
molecular hyperpolarizabilities. Unfortunately, the trade-off that
exists between the transparency and the nonlinearity has
restricted the use of these molecules. On the macroscopic side,
the ability to assemble these molecules in a noncentrosymmetric
phase, such as noncentrosymmetric crystals, poled polymers,
or Langmuir-Blodgett films is, in general, still unsatisfactory.
The use of chiral molecules has been among the strategies to
guarantee a noncentrosymmetric structure of dipoles in order
to obtain a nonvanishing macroscopic susceptibility, ø(2).
However, depending on the nature of the chiral center, the
D-π-A part of such optically active molecules is still able to
orient in a pseudocentrosymmetric way. There are still no
The field of nonlinear optics includes studies of second- and
third-order nonlinear optical properties, such as electro-optic
and photorefractive effects, second-harmonic generation, etc.1
Due to high molecular hyperpolarizabilities organic molecular
materials and polymers display a number of significant nonlinear
optical properties and hence are emerging as possible materials
for future technologies of next generation telecommunication
technologies, optical information processing, and storage. The
ultimate goal, the construction of devices for technological
applications from organic chromophores, remains a challenge
due to problems at the microscopic (molecular) and macroscopic
(bulk) levels. On the microscopic side, it is well-known that
the classical conjugated donor-acceptor substituted organic
molecules2 and the more recent octopolar3 molecules have high
(3) (a) Ledoux, I.; Zyss, J.; Siegel, J. S.; Brienne, J.; Lehn, J.-M. Chem.
Phys. Lett. 1991, 172, 440. (b) Verbiest, T.; Clays, K.; Samyn, C.; Wolff,
J.; Reinhoudt, D.; Persoons, A. J. Am. Chem. Soc. 1994, 116, 9320.
(4) (a) Bahl, A.; Grahn, W.; Stadler, S.; Feiner, F.; Bourhill, G.; Bra¨uchle,
C.; Reisner, A.; Jones, P. G. Angew. Chem., Int. Ed. Engl. 1995, 13, 1485.
(b) Bjørnholm, T.; Geisler, T.; Larsen, J.; Jørgensen, M.; Brunfeldt, K.;
Schaumburg, K.; Bechgaard, K. Synth. Met. 1993, 57 (1), 3813. (c)
Bjørnholm, T.; Geisler, T.; Larsen, J.; Jørgensen J. Chem. Soc., Chem.
Commun. 1992, 11, 815.
* To whom correspondence should be addressed.
† University of Copenhagen.
‡ Center for Research on Molecular Electronics and Photonics.
§ Risø National Laboratory.
X Abstract published in AdVance ACS Abstracts, July 1, 1996.
(1) (a) Prasad, N. P.; Williams, D. J. Introduction to Nonlinear Optical
Effects in Molecules and Polymers; Wiley: New York, 1991. (b) Materials
for nonlinear Optics: Chemical PerspectiVes; Marder, S. R., Sohn, J. E.,
Stucky, G. D., Eds.; ACS Symposium Series 455; American Chemical
Society: Washington, DC, 1991. (c) Boyd, R. W. Nonlinear optics;
Academic Press: New York, 1992. (d) Shen, Y. R. The Principles of
Nonlinear Optics; Wiley: New York, 1984.
(2) (a) Cheng, L.-T.; Tam, W.; Stevenson, S. H.; Meredith, G. R.; Rikken,
G.; Marder, S. R. J. Phys. Chem. 1991, 95, 10631. (b) Cheng, L.-T.; Tam,
W.; Marder, S. E.; Stiegman, A. E.; Rikken, G.; Sprangler, C. W. J. Phys.
Chem. 1991, 95, 10634.
(5) (a) Nalwa, H. S.; Watanabe, T.; Miyata, S. AdV. Mater. 1995, 7,
754. (b) Kelderman E.; Derhaeg, L.; Heesink, G. J.; Verboom, W.;
Engbersen, J. F.; Van Hulst, N. F.; Persoons, A.; Reinhoudt, D. Angew.
Chem., Int. Ed. Engl. 1992, 31, 1075. (c) Watanabe, T.; Yamamoto, H.;
Hosomin, H.; Miyata, S. in Organic Molecules for Nonlinear Optics and
Photonics; Messier, J., et al., Eds.; NATO ASI Series; 1991, Vol. 194, p
151. (d) Tsunekawa, T.; Gotho, T.; Mataki, H.; Iwamoto, M. In Nonlinear
Optical Properties of Organic Materials III; Khanarian, G., Ed.; Proc. SPIE;
1990, Vol. 1337, p 285. (e) Katz, H. E.; Schilling, M. L.; Holland, W. R.;
Fang, T. In Materials for Nonlinear Optics - Chemical PerspectiVes;
Marder, S. R., et al., Eds.; ACS Symposium Series; American Chemical
Society: Washington, DC, 1991, Vol. 455, p 567.
S0002-7863(96)00076-5 CCC: $12.00 © 1996 American Chemical Society

6842 J. Am. Chem. Soc., Vol. 118, No. 29, 1996
Deussen et al.
second-order molecular hyperpolarizability tensor will have
several significant tensor components. Since hyper-Rayleigh
scattering (HRS) and electric-field-induced second-harmonic
generation (EFISHG) assess different combinations of the
components of the molecular hyperpolarizability tensor, we
expect both techniques to give complementary information. The
study of these molecules and the influence of their conformation
on the second-order nonlinear optical response may provide an
important step toward supramolecular engineering of nonlinear
optical properties.
The synthesis is discussed in section I. In section II we
present the linear optical properties and develop a model to
express the ratio between the two main tensor components in
terms of the dihedral angle between the two dipolar naphthyl
units. The theory that is relevant for the analysis of the HRS
and EFISHG measurements is also included in this section. In
section III we present and discuss the experimental results
obtained with these techniques. The conclusion is presented
in section IV followed by section V, where the synthesis of all
new compounds will be presented.
Figure 1. General structures of the bis-dipolar dimers, the monomers,
and their dipole orientations.
accurate means of predicting the molecular packing in the
crystalline state in order to guarantee deviation from antiparallel
orientation of the dipoles in the bulk material. In order to
overcome some of the above-mentioned obstacles, new strategies
different from the classical one-dimensional (1D) charge transfer
(CT) and octopolar molecules have been suggested. These
include avoiding the direct conjugation between donor and
acceptor using through space interactions,4 and just recently,
the use of two-dimensional (2D) charge-transfer molecules5 has
been reported.
The present paper deals with a bis-dipolar approach: two
one-dimensional molecular units are connected together, leading
to a three-dimensional V-shaped molecular structure.6 In the
dimeric binaphthol (BN) system (types a and b) (Figure 1),
which is axially chiral with C2 symmetry, two monomers of
â-naphthol (type c) are connected at the 1,1′-positions. This
leads for the 6,6′-diacceptor-substituted BN to a bis-dipolar
molecule consisting of two donor-acceptor monomers of
6-acceptor-substituted â-naphthol.
In order to obtain further information, molecules based on
this geometry, with strong acceptors and long conjugation
lengths between donor and acceptor, were synthesized. We have
prepared two types of chiral molecules: open chain BN-ethers
(type a) with R ) ethyl and closed bridge BN-acetals (type b).
The latter was chosen in order to force the dipoles into the
closest possible proximity to each other. Two of the corre-
sponding monomers (type c) with R ) n-butyl were prepared
as references. According to X-ray diffraction on a racemic 6,6′-
dicyano-substituted (type b) compound, the two naphthyl
moieties display a dihedral angle of 54°. In the BN acetals
this angle is mainly determined by the conformational energy
of the heterocyclic ring, whereas in the open BN the angle
between the two naphthyl moieties can vary, depending on
packing effects in crystals, and solvent polarity and temperature
in solution, as well as on dipole-dipole interactions in general.7
Unlike the classical dipolar molecules, the bis-dipolar com-
pounds here possess two charge-transfer units within a molecule.
For these nonplanar molecules, it can be anticipated that the
I. Synthesis
1. Introduction. Starting from optically pure 2,2′-dihy-
droxy-1,1′-binaphthyl 1, the synthesis of all compounds pro-
ceeded by bromination in the 6,6′-positions followed by the
alkylation of the hydroxy groups for the acetals (type b) or by
reversed reaction order for the ethers (type a). By transforma-
tion of the dibromo compounds 4a and 4b to the formyl
compounds 5a and 5b, the functionality, necessary for further
reactions, was introduced. Reactions with the corresponding
phosphonates by a Horner-Emmons reaction or by a Knoe-
venagel condensation yielded the desired enantiomeric push-
pull (donor-acceptor-substituted) binaphthol derivatives.
The optical purity of the closed dimers (type b) was tested
1
by H-NMR (400 MHz) in the presence of the chiral alcohol
(R)-(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol ((R)-(-)-TFAE from
Aldrich): the methylene hydrogen signal of racemic 9,14-
dibromodinaphtho[2,1-d:1′,2′-f][1,3]dioxepin (4b) was split 4-5
Hz due to the diastereomeric interaction with a large excess of
(R)-(-)-TFAE. Only one optical isomer was found for all
compounds tested. As a higher racemization barrier was found
for open BN derivatives (type a),8 their enantiomeric purity can
be deduced from the results obtained for the closed dimers (type
b), indicating that no racemization took place during the
reactions.
2. Synthesis of the 6,6′-Dibromobinaphthol derivatives
4a and 4b. Optically pure binaphthol (BN) was obtained
according to Kazlauskas.9 The bromination of optically pure
BN has been reported by Sogah and Cram,10 and due to the
difficulties with the purification of the dibromo diol 3a the crude
product was used as starting material. For the further synthetic
steps dibromodiol 3a could be alkylated with dibromomethane
in boiling acetone and K2CO3 as a base, giving the acetal 4b in
nice yield (Scheme 1). In the latter reaction intramolecular ring
closure took place exclusively. Direct alkylation of 1 with ethyl
bromide using similar conditions gave 2 which could easily be
brominated at room temperature to give 4a. This reaction
sequence, alkylation in the first step followed by bromination,
was much more advantageous, as 2 was easy to purify by a
single recrystallization. In comparison to the described methoxy
(6) (a) Wong, M. S.; Nicoud, J. F. J. Chem. Soc., Chem. Commun. 1994,
249. (b) Wong, M. S.; Nicoud, J. F. Nonlinear Opt. 1995, 9, 181. (c)
Andraud, C.; Brotin, T.; Garcia, C.; Pelle´, F.; Goldner, P.; Bigot, B.; Collet,
A. J. Am. Chem. Soc. 1994, 116, 2094.
(8) Solladie´, G.; Zimmermann, R. G. Angew. Chem. Int. Ed. Engl. 1984,
23, 348.
(7) (a) Thorup, N.; Deussen, H. J.; Bjørnholm, T.; Bechgaard, K. Poster
at ECM 16 Lund, 16th European Crystallographic Meeting, Aug 6-11,
1995, Lund, Sweden. (b) Suchod, B.; Renault, A.; Lajzerowicz, J.; Spada,
G. P. J. Chem. Soc., Perkin Trans. 2 1992, 1839.
(9) Kazlauskas, R. J. Org. Synth. 1992, 70, 60.
(10) Sogah, G. D. Y.; Cram, D. J. J. Am. Chem. Soc. 1979, 101, 3035.
(11) (a) Gottarelli, G.; Spada, G. P. J. Org. Chem. 1991, 56, 2096 (b)
Groves, J. T.; Viski, P. J. Org. Chem. 1990, 55, 3628.

Bis-dipolar 6,6′-Disubstituted Binaphthol DeriVatiVes
Scheme 1. Syntheses of 2, 3a, 4a, and 4b
J. Am. Chem. Soc., Vol. 118, No. 29, 1996 6843
Scheme 2. Syntheses of 5a, 6a, 7a, 8a, and 9a
Scheme 3. Syntheses of 5b, 6b, 7b, 8b, and 10b
ylene derivative 6a by means of the Knoevenagel condensation12
with malononitrile using a catalytic amount of piperidine as a
base in methylene chloride. Compound 7a was synthesized by
condensation of the aldehyde 4a with ethyl cyanoacetate under
similar conditions as mentioned above, but using CHCl3 as
solvent. The (E)-configuration of 7a was assigned on the basis
compounds,11 the synthesized ethoxy compounds 2 and 4a here
were easier to crystallize and showed a significantly increased
solubility, necessary in the subsequent synthetic steps.
3. Synthesis of the 6,6′-Diacceptor-Substituted Open BN
Ethers 5a-9a. 4a was lithiated in THF at -78 °C using an
excess of n-BuLi. After 5-6 h an excess of DMF was added,
and subsequent hydrolysis yielded the aldehyde 5a (Scheme 2).
The aldehyde was converted to the corresponding dicyanoeth-
(12) Org. React. 1967, 15, 204.
(13) (a) Hesse, M.; Meier, B.; Zeh, B. Spektroskopische Methoden in
der organischen Chemie, 3rd ed.; Stuttgart, 1987; p 115. (b) Zabicky, J. J.
Chem. Soc. 1961, 683.

6844 J. Am. Chem. Soc., Vol. 118, No. 29, 1996
Scheme 4. Syntheses of 11b and 12b
Deussen et al.
Scheme 5. Syntheses of 4c, 5c, 6c, and 7c
reaction steps were similar to those for the binaphthol derivatives
4a-7a (Scheme 5).
II. Linear and Nonlinear Optical Properties
1. Linear Optical Properties of Compounds 6a-6c and
7a-7c. The absorption spectra of the two types of BN dimers
and of their corresponding references (double concentration)
in CHCl3 are shown in Figures 2 and 3 for two different
acceptors. The tendency is the same for both acceptors 6 and
7: the absorption spectra of the type c and type a molecules
are similar, whereas the closed type b compounds differ
significantly from the others.
The differences of the type b compounds can be explained
by the fact, as shown by X-ray diffraction, that the plane defined
by the oxygen atoms and the carbon atom to which they both
are bound does not coincide with the plane of the aromatic
of the shift of the olefinic proton and was in accordance with
a previous observation obtained for a benzene derivative.13
8a and 9b were synthesized by the Horner-Emmons14
reaction of the corresponding diethyl phosphonates in dimethoxy-
ethane at room temperature using sodium hydride as a base.
Diethyl (cyanomethyl)phosphonate was purchased (Merck);
diethyl (4-nitrobenzyl)phosphonate was synthesized by the
Arbuzov reaction of 4-nitrobenzyl chloride with triethyl phos-
phite which was superior to a procedure previously reported.15
4. Synthesis of the 6,6′-Diacceptor-Substituted Closed BN
Acetals 5b-8b and 10b. The syntheses of the closed BN acetal
derivatives 5b-8b were analogous to the ones described above.
10b and 11b were synthesized by the Horner-Emmons reaction
using conditions similar to those above. The diethyl [(meth-
ylsulfonyl)methyl]phosphonate used for the preparation of 10b
(Scheme 3) was prepared according to a known procedure.16
The vinylogous dialdehyde 11b was synthesized by a two-
step formylolefination using diethyl [2-(cyclohexylamino)vinyl]-
phosphonate (Scheme 4).17 The carbanion of the phosphonate
was conveniently reacted with the aldehyde 5b, giving the R,â-
unsaturated aldimine. This was hydrolyzed in a two-layer
system of CH2Cl2 and a buffer solution to give the unprotected
dialdehyde 11b. The aldehyde was converted to the corre-
sponding dicyanoethylene derivative 12b by means of the
Knoevenagel condensation12 as described earlier.
Figure 2. Absorption spectra of 6a, 6b, and 6c (double concentration)
in CHCl3.
5. Synthesis of the â-Naphthol Derivatives 3c-7c. 3c was
prepared according to a known method.18 The subsequent
(14) Wadsworth, W. S.; Emmons, W. D. J. Am. Chem. Soc. 1961, 83,
1733.
(15) Kagan, F.; Birkenmeyer, R. D.; Strube, R. E. J. Am. Chem. Soc.
1959, 81, 3026.
(16) (a) Fillion, H.; Pe´ra, M.-H.; Rappa, J.-L.; Luu-Duc, C. J. Heterocycl.
Chem. 1978, 15, 753. (b) Posner, G. H.; Brunelle, D. J. J. Org. Chem.
1972, 37, 3547.
(17) Nagata, W.; Wakabayashi, D.; Hayase, Y. Organic Syntheses;
Wiley: New York, 1988; Collect. Vol. VI, p 448.
(18) Koelsch, C. F. Organic Syntheses; Wiley: New York, 1955; Collect.
Vol. III, p 132.
Figure 3. Absorption spectra of 7a, 7b, and 7c (double concentration)
in CHCl3.

Bis-dipolar 6,6′-Disubstituted Binaphthol DeriVatiVes
J. Am. Chem. Soc., Vol. 118, No. 29, 1996 6845
Table 1. Solvatochromic Shifts of Absorption and Fluorescence
Emission of Compounds 6a-6c and 7a-7c
Stokes
Stokes
com-
λ
max (nm) λmax (nm) λfluor (nm) λfluor (nm) shift (eV) shift (eV)
pound (n-hexane) (CH2Cl2) (n-hexane) (CH2Cl2) (n-hexane) (CH2Cl2)
6a
6b
6c
7a
7b
7c
399
385
389
391
377
379
407
385
394
389
378
377
442
421
421
437
418
413
494
481
459
485
470
453
0.302
0.275
0.242
0.334
0.323
0.269
0.537
0.643
0.446
0.631
0.642
0.552
rings.7a Thus, the electron-donating lone pairs of the oxygen
atoms are twisted out of conjugation with the aromatic system.
This loss of donor strength is reflected in the hypsochromic
shift of the absorption spectra.
The similarity between the spectra of 1,1′-binaphthyl and
naphthalene has been attributed to the lack of coplanarity
between the naphthyl moieties in 1,1′-binaphthyl due to steric
hindrance.19 The INDO/CI calculated potential energy curve
of 1,1′-binaphthyl shows a broad minimum located around an
angle between the two naphthalene units at 90°.20 The minimum
was found to be delimited by two steep walls at angles of 60°
and 130° due to the strong steric interactions experienced by
the molecule approaching planarity. At room temperature, the
molecule is expected to oscillate around the perpendicular form.
For the bis-dipolar BN, the similarity of the absorption spectra
between the monomeric dipolar naphthol ethers (type c) and
the open bis-dipolar BN ethers (type a) again demonstrates the
lack of coplanarity. As the steric hindrance is not affected by
the substitution, we still expect the potential energy curve to
be delimited by the steric hindrance. Even though the dipolar
interactions can introduce some asymmetry in the shape of the
potential well since they favor antiparallel geometries, we do
not expect that this effect is strong enough to prevent oscillation
around the perpendicular form.
Still the absorption maxima at longer wavelengths of the type
a BN are shifted bathochromicly by 10-15 nm in comparison
to the monomers (type c). Since the two dipoles are oriented
nearly perpendicular, the interaction energy between the two
dipoles should be negligible. A possible explanation for the
observed shifts could be the different interactions of the dipoles
with the solvent. The effect of a solvent on a polar molecule
can be described by Onsager’s reaction field model.21 In this
model, the polar molecule is taken to occupy a spherical cavity
and generates a reaction field directly proportional to and in
the same direction as the molecular dipole moment. As the
dipole moment of the type a BN will be larger than that of the
monomeric units, the reaction field will also be larger for the
type a BN, and consequently, the absorption maxima will be
red-shifted for the type a BN. As the difference in dipole
moment of the type a BN and their corresponding monomers
will be even larger in the excited state, the bathochromic shift
is even more significant if we look at the Stokes shifts (Table
1) of fluorescence emission, which are related to the change in
dipole moment from the ground to excited state (∆µge).22
It can be deduced from the solvatochroism of both absorption
(the apparent discrepancy for 7a and 7c is due to the occurrence
of a fine structure in n-hexane which is misleading) and
fluorescence of 6a-c and 7a-c23 that all the molecules display
Figure 4. Absorption spectrum of 7a in n-hexane and fluorescence
emission in solvents of different polarity.
Figure 5. Model geometry of the coupled dipolar NLO units. Both
âzzz tensor components are lying in a plane parallel to the ZX plane
and make an angle of θ/2 deg with the 2-fold axis that is chosen as the
Z axis of the reference frame of the dimer.
the necessary charge-transfer properties and thus fulfill the
requirements for effective NLO materials according to the two-
level model (Figure 4).1
2. Molecular Hyperpolarizability Tensor. A simple model
can be used to express the ratio of the different molecular tensor
components of the BN dimer in terms of the dihedral angle
between the dipolar naphthyl units. As the two linked mono-
meric units each have dipolar symmetry, we further assume that
their only significant tensor component is âzzz, where z is in the
direction of the charge transfer in the monomeric unit. Quantum
chemical calculations24 and depolarized HRS measurements25
have shown that this approach is accurate within 10-15% for
conjugated organic chromophores. If we also allow the angle
between the two âzzz tensor components to vary, these assump-
tions lead to the simplified geometry shown in Figure 5.26
(23) From the plot of the energy difference between the first fluorescence
band and the first absorption band against the Onsager solvent polarity
function in a series of solvents of different polarity, the changes in dipole
moment from ground to excited state (∆µge) were determined according to
ref 22, to give the following values (D): 6a,13; 6b,14; 6c, 10; 7a, 16; 7b,
14; 7c, 8.
(19) Friedel, R. A.; Orchin, M.; Reggel, L. J. Am. Chem. Soc. 1948, 70,
199.
(20) Baraldi, I.; Ponterini, G.; Momicchioli, F. J. Chem. Soc., Faraday
Trans, 2 1987, 83 2139.
(21) Bo¨ttcher, C. J. P. Theory of Electric Polarization; Elsevier:
Amsterdam, 1973.
(22) (a) Lippert, E. Elektrochem. 1957, 61, 962. (b) Suppan, P. J.
Photochem. Photobiol., A: Chem. 1990, 50, 293.
(24) Kanis, D. R.; Ratner, M. A.; Marks, T. J. Chem. ReV. 1994, 94,
195.
(25) Heesing, G. J. T.; Ruiter, A. G. T.; van Hulst, N. F.; Bo¨lger, B.
Phys. ReV. Lett. 1993, 71, 999.
(26) The choice of the model geometry and tensor components is
furthermore justified by semiempirical calculations (PM3), which indicate
that the two major tensor components are âZZZ and âZXX. The next significant
component âZYY is less than 17% of the sum of âZZZ and âZXX
.

6846 J. Am. Chem. Soc., Vol. 118, No. 29, 1996
Deussen et al.
According to this model, the tensor components of the dimer
in the XYZ reference frame are given by
For a liquid composed of noncentrosymmetric molecules the
macroscopic polarization oscillating at the harmonic frequency
2ω will be equal to
âIJK,dimer ) 2 cosI,z cosJ,z cosK,z âzzz,monomer
(1)
bP(2ω) ) B(-2ω;ω,ω) bE(ω) bE(ω)
(5)
Since the molecule has a 2-fold axis, the two monomeric tensor
components have the same magnitude.
with B(-2ω;ω,ω) the macroscopic nonlinear second-order
susceptibility tensor for frequency doubling. Due to the
orientational fluctuations of the molecules in solution it is only
the average value of B(-2ω;ω,ω) that is equal to zero. If the
incident light travels in the U direction and is polarized in the
W direction while the scattered light is observed in the V
direction, the intensity of the HRS signal will be equal to
If I, J, or K ) Y, then âIJK will be equal to zero since cosY,z
) cos 90° ) 0. Furthermore, since the dimer in the model has
C2V symmetry, we are left with only four nonzero tensor
components, âZZZ, âZXX, âXZX, and âXXZ. According to eq 1,
the magnitude of these components is given by
3
θ
2
âZZZ ) 2 cos âzzz,monomer
(2)
(
)
I(2ω) ) IU(2ω) + IW(2ω) )
G( BWWW + BUWW )IW2(ω) (6)
2
2
2
θ
2
θ
2
âZXX ) âXZX ) âXXZ ) 2 cos sin âzzz,monomer (3)
(
)(
)
I(2ω) is the intensity of the light at frequency 2ω, traveling in
the V direction. Both the U and W polarized components of
the harmonic light are measured. The angular brackets indicate
orientational averaging and G is an instrumental factor that
remains unchanged during a measurement. For a solution
composed of noninteracting solvent (S) and solute (s) molecules,
the macroscopic nonlinear susceptibility of the solution can be
written as a function of the corresponding microscopic hyper-
polarizabilities and number densities of the solvent and solute
molecules:
since cos(90 - θ/2) ) sin(θ/2). The fact that âZXX ) âXZX
)
âXXZ can also be obtained assuming Kleinman27 or intrinsic
permutation symmetry, but here it simply follows from the
model used.
Thus, if the angle θ/2 can be determined by X-ray diffraction
or semiempirical calculations, we can immediately calculate the
ratio of the two independent tensor components according to
â
2
θ
2
ZXX ) tan
(4)
(
)
âZZZ
2
2
4
2
2
2
BWWW + BUWW ) fω f2ω
N ( â
+ âUWW )
p
∑
p
WWW
p)s,S
We will use this model and eq 4 for the analysis of the hyper-
Rayleigh scattering and electric-field-induced second-harmonic
generation measurements. From symmetry considerations and
vector addition it is also obvious that the dipole moment of the
dimer is directed along the Z axis.
(7)
where fω and f2ω are the local field correction factors at the
fundamental and the harmonic frequencies, respectively.
2
If we define âHRS by
An additional conformational mobility is the flexibility of
the vinyl- or styrylnaphthalene moiety. It was concluded earlier
that 2-styrylnaphthalene exists in solution as an equilibrium
mixture of two roughly isoenergetic conformers (in anti and
synconformations) and that no steric factors impede the inter-
conversion of the postulated conformers.28 For 2-vinylnaph-
thalene the dominant conformation was found by NMR spec-
troscopy to be anti, with a dihedral angle R formed by the
naphthyl and vinyl plane of 18.3° ( 3.1°. A 2-fold rotational
barrier of 4.0 ( 0.4 kcal/mol was found for styrene.29 However,
the preferred vinyl and styryl conformations were found by PM3
calculations to be independent of the conjugate naphthalene
framework (open chain BN ethers, closed BN acetals, and the
â-naphthol monomers). This justifies ommiting the additional
conformationally mobility in the above model, as these contri-
butions will be the same for different dihedral angles θ between
the naphthalene moieties.
2
2
2
âHRS ) âUWW + âWWW
(8)
this leads to the following equation for the intensity of the
scattered field:
4
2
2
2
I(2ω) ) Gfω fω (NS âHRS S + Ns âHRS s)IW2(ω) (9)
For the analysis of the HRS results of the dimers, Ns is equal to
the number density of the dimers. This implies that the
harmonic fields of two monomeric units interfere if the
monomeric units belong to the same dimer. There are no fixed
phase relations between the harmonic fields of two dimers or
two independent molecules in an isotropic solution. Thus, by
2
performing the orientational average, we can link âHRS to the
components of the molecular hyperpolarizability tensor. For
the dimers, since Ns is equal to the number density of the dimers,
âHRS is composed of the tensor components of the molecular
hyperpolarizability tensor of the dimer. For a fully symmetrical
tensor, i.e., assuming Kleinman and intrinsic permutation
symmetry, this relation is given by
3. Hyper-Rayleigh Scattering. As hyper-Rayleigh scat-
tering (HRS) has so far not been applied to deduce numerical
values for several tensor components, we find it useful to treat
this technique in a more detailed fashion. An HRS measurement
is performed by measuring the intensity of the second-order
scattered light on focusing an intense laser beam, with frequency
ω, on an isotropic solution.30 For a detailed description of the
experimental setup the reader is referred to ref 31.
2
6
16
38
2
2
2
âHRS
)
â
+
â â +
â
iij
+
∑
∑
∑
iii
iii ijj
35
105i*j
105i*j
i
(27) Kleinman, D. A. Phys. ReV. 1962, 126, 1977.
(28) Haas, E.; Fischer, G.; Fischer, E. J. Phys. Chem. 1978, 14, 1638.
(29) Facchine, K. L.; Staley, S. W.; van Zijl, P. C. M.; Mishra, P. K.;
Bothner-By, A. A. J. Am. Chem. Soc. 1988, 110, 4900.
(30) (a) Clays, K.; Persoons, A. Phys. ReV. Lett. 1991, 66, 2980. (b)
Clays, K.; Persoons, A.; De Maeyer, L. AdV. Chem. Phys. 1994, 85 (III),
455.
16
20
35
2
â â
+
âijk (10)
∑
iij jkk
105ijk,cycl
where the summations over i * j contain six terms each, and
the summation over ijk, cycl contains three terms (âXXYâYZZ
âYYZ ZXX, âZZX XYY), as is also the case with the summation over
,
(31) Clays, K.; Persoons, A. ReV. Sci. Instrum. 1992, 63, 3285.
â
â

Bis-dipolar 6,6′-Disubstituted Binaphthol DeriVatiVes
J. Am. Chem. Soc., Vol. 118, No. 29, 1996 6847
âZ ) âZZZ + âZXX (17)
i.32 It is clear from this equation that HRS is sensitive to an
isotropic average of all molecular tensor components.
For dipolar molecules such as p-nitroaniline, with only one
significant âZZZ tensor component, eq 10 reduces to
Thus, EFISHG is sensitive to the sum of the two main tensor
components of the BN dimers, while HRS is sensitive to the
sum of the two main tensor components squared, each multiplied
by a factor originating from the orientational average. The
dipole moments were determined experimentally according to
the procedure outlined in ref 34. As the Z axis of the dimer
coincides with the 2-fold axis, the only component of the
molecular dipole moment will be µZ. For EFISHG â values,
the estimated uncertainties are (15%.
6
35
2
2
âHRS
)
âZZZ
(11)
For the BN dimers, according to the model presented above,
there will only be two significant independent tensor compo-
nents, âZZZ and âZXX ) âXZX ) âXXZ. If we only take these
components into account, we are left with
III. Results and Discussion
6
35
16
105
38
105
2
2
2
The molecular hyperpolarizabilities (â) have been determined
using both EFISHG and HRS, and the results are shown in
Tables 2-4. The obtained values are listed in units of 10-30
esu and were measured at 1064 nm in chloroform. Since
fluorescence at 532 nm is known to artificially enhance the
retrieved value for the first hyperpolarizability measured by
HRS,35 all the compounds were tested for fluorescence emission
at this wavelength. No significant fluorescence at this wave-
length was observed for any of the compounds.
âHRS
)
âZZZ
+
â
ZZZâZXX
+
âZXX
(12)
Equations 9, 11, and 12 are used to analyze the HRS measure-
ments and to obtain an averaged value for the molecular
hyperpolarizability. At low solute concentration, NS in eq 9
can be taken as a constant, and the slope of a plot of the
experimentally determined ratio I(2ω)/IW2(ω) versus Ns will be
equal to
We first focus our attention on the monomers (type c). For
these simple dipolar molecules, it is obvious that âzzz, where z
is directed along the charge-transfer axis, is the largest
component of the molecular hyperpolarizability tensor. As a
result, both EFISHG and HRS measure the same value for the
molecular hyperpolarizability. In good agreement with the
position of the absorption band maxima, the hyperpolarizability
of the molecule with the dicyanovinyl acceptor 6c is larger than
the hyperpolarizability of the molecule with the cyanocarbo-
ethoxyvinyl 7c acceptor due to the higher acceptor strength of
the dicyanovinyl acceptor (Table 2).
4
2
2
slope ) Gfω fω âHRS
(13)
This slope is determined for a dilution series of p-nitroaniline
in chloroform (â ) 23 × 10-30 esu)30a and for a dilution series
of the molecule with the unknown hyperpolarizability. The ratio
of the two slopes is proportional to
(6/35)(23)2
slopepna
)
(14)
2
slopex
âHRS
x
The results obtained for the dimers in the open form (type a)
are listed in Table 3. To analyze the HRS results, a value of
45° for θ/2 was introduced in eq 4 to calculate a ratio of 1
between âZZZ and âZXX, or âZZZ ) âZXX. This average value
was determined by semiempirical PM3 calculations.36 Introduc-
ing this ratio into eq 12 gives
From this equation the unknown averaged hyperpolarizability
can easily be calculated. The estimated uncertainty of all
experimental HRS results is (10%.
4. Electric-Field-Induced Second-Harmonic Generation.
The EFISHG technique is a standard technique for the deter-
mination of the first hyperpolarizability.33 Unlike HRS, EFISHG
uses a dc electric field to break the centrosymmetry of the
solution. As there are three fields involved, the total contribu-
tion to the nonlinear polarization oscillating at the harmonic
frequency is given by the microscopic second hyperpolarizability
γ0, which can be written as the sum of an electronic and an
orientational contribution:
2
2
âHRS ) 0.686âZZZ
(18)
Using eqs 18 and 14, the âZZZ tensor component of the dimer
can easily be determined. Since âZZZ ) âZXX, the other
component is also known. Using eqs 2 and 3, these dimer tensor
components can be linked to the tensor component of the dipolar
monomeric units. EFISHG, on the other hand, is sensitive to
γ0 ) γe + µZâZ/5kT
(15)
the sum of the two tensor components of the dimer: to âZZZ
+
+
â
ZXX. As can be seen in Table 3, the EFISHG values (âZZZ
ZXX) are in excellent agreement with the sum of the two
For conjugated organic molecules with a large first hyperpo-
larizability and dipole moment, it is usually assumed that γe
can be neglected. The Z axis is in the same direction as the
molecular dipole moment, and âZ is given by
â
components determined by HRS (âZZZ + âZXX).
It is also clear that the â tensor components of the dipolar
monomeric unit as well as the tensor components of the dimer
increase with increasing acceptor strength and with increasing
conjugation length. Furthermore, for the dimers with the
dicyanovinyl and the cyanocarbethoxyvinyl acceptors (6a and
7a), the calculated tensor components of the dipolar monomeric
units are in good agreement with the hyperpolarizabilities of
âZ ) âZZZ + (1/3)(âZXX + âZYY + âXZX + âYZY
+
âXXZ + âYYZ) (16)
If we make the same assumptions for the molecular tensor
components of the BN dimers as in section 2.2, this equation
reduces to
(34) Nackaerts, R. Ph.D. Thesis 1983, University of Leuven, Belgium,
1983.
(35) Hendrickx, E.; Dehu, C.; Clays, K.; Bre´das, J.-L.; Persoons, A.
Polymers for Second-Order Nonlinear Optics; ACS Symposium Series;
American Chemical Society: Washington, Dc, 1995; Vol. 601.
(36) Simple vector calculation of the determined dipole moments of 6a,
6c and 7a, 7c assuming the V-shape model with C2V symmetry (Figure 5)
gives a calculated dihedral angle θ of 78° for 6a and of 89° for 7a in good
agreement with the results of PM3 calculations.
(32) (a) Cyvin, S. J.; Rauch, J. E.; Decius, J. C. J. Chem. Phys. 1965,
43, 4083 (b) Bersohn, R.; Pao, Y.-H.; Frisch, H. L. J. Chem. Phys. 1966,
45, 3184.
(33) (a) Levine, B. F.; Bethea, C. G. J. Chem. Phys. 1975, 63, 2666. (b)
Singer, K. D.; Garito, A. F. J. Chem. Phys. 1981, 75, 3572. (c) Meredith,
G. R. ReV. Sci. Instrum. 1982, 53, 48.

6848 J. Am. Chem. Soc., Vol. 118, No. 29, 1996
Deussen et al.
Table 2. Molecular Hyperpolarizabilities (â) of 6c and 7c in Units
components of the dimer and the dipolar monomeric units
increase with increasing acceptor strength and increasing
conjugation length.
of 10-30 esu (1064 nm, CHCl3)
compound
âHRS
âEFISHG
6c
7c
79
64
87
64
IV. Conclusion
In conclusion, we have prepared novel 6,6′-diacceptor-
substituted chiral binaphthol derivatives for nonlinear optical
applications based on two different molecular geometries
displaying different acceptor strengths. A model was developed
to account for the bis-dipolar character of the first molecular
hyperpolarizability tensor. These components can be expressed
in terms of the hyperpolarizabilities of the dipolar one-
dimensional monomeric units and the dihedral angle between
these monomers. The ratio between the two independent tensor
components of the dimers was calculated using this model, and
values for the dihedral angle from either X-ray diffraction or
semiempirical PM3 calculations. This ratio is then used to
analyze the results obtained by hyper-Rayleigh scattering.
By comparison of the tensor components determined using
this model and the HRS measurements to the EFISHG measure-
ments, the following conclusions can be drawn: (i) Results from
EFISHG and HRS measurements are in excellent mutual
agreement for the monomers, the open dimers, and the closed
dimers. (ii) The values of the tensor components of the open
dimers (type a) are significantly larger than the values of the
tensor components of the corresponding closed dimers (type b)
due to the bad conjugation between the electron donor and the
aromatic system in the closed forms. (iii) For the open dimers
an average value of 46° ( 11° has been calculated for θ/2 using
Table 3. Molecular Hyperpolarizabilities (â) of 6a, 7a, 8a, 9a,
and Their Hypothetical Monomers (See Text) in Units of 10-30 esu
(1064 nm, CHCl3)
com-
pound
HRS:
âzzz
HRS:
âzxx
HRS:
âmono
HRS:
âzzz + âzxx
EFISHG:
âzzz + âzxx
6a
7a
8a
9a
68
59
47
68
59
47
96
83
66
136
118
94
135
103
102
344
182
182
255
364
Table 4. Molecular Hyperpolarizabilities (â) of 6b, 7b, 8b, 10b,
12b, and Their Hypothetical Monomers (See Text) in Units of 10-30
esu (1064 nm, CHCl3)
com-
pound
HRS:
âzzz
HRS:
âzxx
HRS:
âmono
HRS:
âzzz + âzxx
EFISHG:
âzzz + âzxx
6b
7b
8b
54
46
27
14
12
7
37
32
19
68
58
34
65
95
34
10b
12b
31
193
8
50
22
132
39
243
45
219
the monomers 6c and 7c listed in Table 2. This indicates that
a strong interaction exists between the electron donor and the
electron acceptor and is in accordance with the proposed model
(Figure 5).
2
âHRS and âEFISHG. (iv) The hyperpolarizability of the free
monomers (type c) is equal to the hyperpolarizability of the
dipolar monomeric units of the corresponding dimers (type a),
indicating a strong electron donor-acceptor interaction in the
open forms. (v) The values for the tensor components of the
free monomers, open dimers, and closed dimers follow the
expected increase in magnitude with increasing acceptor strength
and increasing conjugation length.
Finally, we have presented a new approach to analyze the
hyperpolarizability tensor of bis-dipolar molecules. We have
demonstrated that EFISHG and HRS can be used to obtain
complementary information on the molecular hyperpolarizability
tensor. This approach is an important step toward a quantitative
characterization of the nonlinear optical response of supramo-
lecular systems where a large number of chromophores are
assembled in a noncentrosymmetric manner.
Since the angle θ/2 is not accurately known for the open BN
2
(type a), the value for this angle will be determined using âHRS
2
and âEFISHG. From âHRS (eq 12) and âEFISHG (eq 17) we can
easily calculate âZZZ and âZXX, which are related to θ/2 by eq 4.
If this is done using the measurement results of 6a, 6c and 7a,
7c, we find an average value of 46° ( 11° for θ/2 in good
agreement with the minimum of the calculated potential energy
curve for 1,1′-binaphthyl20 and of the dihedral angle calculated
by PM3 calculations for these compounds.
The results obtained for the closed dimers (type b) are listed
in Table 4. According to X-ray diffraction, the two naphthyl
units display a dihedral angle of 54° in a racemic 6,6′-dicyano-
substituted compound.7a,37 For the analysis of the HRS results
of the closed dimers (type b), a value of 27° for θ/2 was
introduced in eq 4 to calculate a ratio of 0.26 between âZZZ and
The effect of the special expression of chirality in the BN
systems on the intermolecular packing of the molecules and
hence the overall dipolar nature of the resulting materials has
not been addressed here, but will be presented in a forthcoming
paper, including the crystal structures and the NLO properties
of the crystals for a number of compounds.38
â
ZXX, or 0.26âZZZ ) âZXX. Inserting this ratio into eq 12 gives
2
2
âHRS ) 0.234âZZZ
(19)
Using eqs 19 and 14, the tensor components of the dimer can
be determined. The sum of these two components is compared
to the EFISHG âZZZ + âZXX values. These EFISHG values (âZZZ
+ âZXX) are again in good agreement with the corresponding
HRS values (âZZZ + âZXX).
If the tensor components of the dipolar monomeric units (of
type b) are calculated using eqs 2 and 3 and a value of 27° for
θ/2, then these values are significantly lower than the values of
the open monomers (type c), or of the calculated monomers of
the corresponding open dimers (of type a). This can be
attributed to the poor overlap between the electron lone pairs
of the oxygen atom and the aromatic rings. As mentioned
before, this loss of donor strength is also reflected in the
hypsochromic shift of the absorption spectra. Again the tensor
V. Experimental Section
General Procedures. 1H and 13C NMR spectra were recorded on
a Jeol FX 90Q, a Bruker AM-250, or a Varian Unity 400 as noted.
The chemical shifts are reported in δ (ppm) relative to tetramethylsilane
as internal standard. UV-vis spectra were recorded on a Perkin-Elmer
Lambda 9 spectrophotometer. Fluorescence spectra were recorded on
a Perkin-Elmer LS-5 luminescence spectrometer. Optical rotations were
measured on a Perkin-Elmer 141 polarimeter at 25 °C. Mass spectra
were recorded on a VG Masslab12-250 and on a a Jeol JMS-HX/
HX110A tandem mass spectrometer. Gas chromatographic analyses
were performed on a Hewlett-Packard 5890 Series II instrument with
a 5972 series detector, using a 30 m × 0.25 mm HP.5 MS (0.25 µm,
(37) PM3 calculations give an angle of 47° for this compound and all
closed dimers (type b) independent of the substitution in the 6,6′-positions.
(38) Deussen, H. J., Thorup, N.; Boutton, C.; Geisler. T.; Persoons, A.;
Bjørnholm, T.; Manuscript in preparation.

Bis-dipolar 6,6′-Disubstituted Binaphthol DeriVatiVes
J. Am. Chem. Soc., Vol. 118, No. 29, 1996 6849
cross-linked 5% phenyl methyl silicone) column. IR spectra were
recorded on a Perkin-Elmer FT-IR1760X spectrometer. Elemental
analyses were performed at the Microanalysis Laboratory at the
University of Copenhagen. Melting points were measured on a Bu¨chi
apparatus or on a homemade heating stage and are corrected. All
solvents and reagents were obtained from commercial sources and used
without further purification, unless otherwise noted. THF was distilled
under N2 from Na/benzophenone, and DMF and DME were distilled
from CaH2. Dry acetone, CH2Cl2, and chloroform were of HPLC grade
as well as all solvents used for spectrophotometry. K2CO3 and NaI were
dried at 150 °C for one week prior to use. Silica and TLC plates were
from Merck: Kieselgel 60, 0.063-0.200 mm, 70-230 mesh ASTM,
and DC-Aluminiumfolien Kieselgel 60 F254, d ) 0.2 mm. The optical
purity of the closed BN dimers (type b) was tested by 1H NMR
(400MHz) in the presence of the chiral alcohol (R)-(-)-2,2,2-trifluoro-
1-(9-anthryl)ethanol ((R)-(-)-TFAE from aldrich): the methylene
hydrogen signals of racemic 9,14-dibromodinaphtho[2,1-d:1′,2′-f][1,3]-
dioxepin (4b) were split 4-5 Hz due to the diastereomer interaction
with a large excess of (R)-(-)-TFAE. Only one optical isomer was
found for all compounds tested.
(S)-2,2′-Diethoxy-1,1′-binaphthyl (2). A mixture of 14.32 g of (S)-
2,2′-dihydroxy-1,1′-binaphthyl (1) (0.05 mol), 32.69 g of bromoethane
(0.30 mol), 28.0 g of dry potassium carbonate, and a catalytic amount
of NaI in 75 mL of dry acetone was stirred magnetically and refluxed
under anhydrous conditions (CaCl2 tube) until the reaction was judged
to be complete as monitored by TLC (usually 2-3 days). After cooling
the reaction mixture was poured into water and extracted 3× with CH2-
Cl2. The combined organic phases were dried over MgSO4, and the
solvent was removed in vacuo after filtration. The remaining oil was
recrystallized from ligroin (80/110 °C) to give 16.20 g (95%) of white
needles after washing with light petroleum ether and drying in air: mp
139 °C; [R]25D ) -85° (c ) 0.2, CHCl3); MS/FAB+ m/z 343 (MH+);
1H NMR (400 MHz, CDCl3) δ 1.05 (t, 6H), 4.04 (m, 4H), 7.13 (br d,
J ) 8Hz, 2H), 7.20 (ddd, J ) 7, 8, 1.5 Hz, 2H), 7.30 (ddd, J ) 7, 8,
1.5 Hz, 2H), 7.42 (d, J ) 9 Hz, 2H), 7.85 (d, J ) 8 Hz, 2H), 7.93 (d,
J ) 9 Hz, 2H); 13C NMR (62.9 MHz, CDCl3) δ 14.88, 65.10, 115.77,
120.58, 123.31, 125.40, 125.93, 127.68, 128.97, 129.15, 134.08, 154.22.
Anal. Calcd for C24H22O2: C, 84.18; H, 6.48. Found: C, 84.10; H,
6.46.
washed with a small volume of cold MeOH and recrystallized from
CH2Cl2/light petroleum ether. The fine crystals that formed in the
freezer were filtered off using a glass frit. The filtrate was concentrated,
and a second crop was obtained after cooling. The combined batches
were dried under reduced pressure, giving 12.25 g (79%) of 4b: mp
213-214 °C (ether); [R]25 ) +600° (c ) 0.1, CHCl3); MS/EI m/z
D
1
456 (M+); H NMR (250 MHz, CDCl3) δ 5.68 (s, 2H), 7.30 (d, 2H),
7.38 (dd, J ) 1.9, 9 Hz, 2H), 7.49 (d, 2H), 7.88 (d, J ) 9 Hz, 2H),
8.09 (d, 2H); 13C NMR (62.9 MHz, CDCl3) δ 103.05, 119.05, 122.06,
125.75, 128.17, 129.48, 130.29, 130.38, 132.79, 151.45. Anal. Calcd
for C21H12Br2O2: C, 55.30; H, 2.65; Br, 35.04. Found: C, 55.43; H,
2.74; Br, 35.14.
6-Bromo-2-butoxynaphthalene (4c). A mixture of 5.20 g of
6-bromo-2-naphthol (3c) (23.31 mmol), 0.95 g of sodium hydroxide
(23.75 mmol) dissolved in a small volume of water, and 3.51 g of
n-bromobutane (25.61 mmol) in THF was refluxed overnight. After
evaporation of the solvent, the residue was dissolved in CH2Cl2 and
washed with water and brine. After drying over MgSO4 and filtration,
the solution was filtered through a pad of silica, and the solvent was
removed in vacuo. The crude product was recrystallized from EtOH
to give 6.03 g (93%) of a white solid: mp 56-57 °C; MS/EI m/z 278
(M+); 1H NMR (250 MHz, CDCl3) δ 1.00 (t, J ) 7 Hz, 3H), 1.52 (m,
2H), 1.82 (m, 2H), 4.05 (t, 2H), 7.08 (d, 1H), 7.15 (dd, J ) 2.4, 9 Hz,
1H), 7.47 (dd, 1H), 7.58 (d, 1H), 7.63 (d, 1H), 7.90 (d, 1H); 13C NMR
(62.9 MHz, CDCl3) δ 13.75, 19.19, 31.14, 67.67, 106.40, 116.75,
119.96, 128.22, 128.28, 129.41, 129.51, 129.82, 133.00, 157.33. Anal.
Calcd for C14H14BrO: C, 60.23; H, 5.42; Br, 28.63. Found: C, 60.26;
H, 5.32; Br, 28.62.
(S)-2,2′-Diethoxy[1,1′-binaphthyl]-6,6′-dicarbaldehyde (5a). A 5.0
g sample of (S)-6,6′-dibromo-2,2′-diethoxy-1,1′-binaphthyl (4a) (10.0
mmol) was dissolved in 120 mL of dry THF under an argon atmosphere.
The magnetically stirred solution was cooled to -78 °C, and 17.6 mL
of n-BuLi in n-hexane (2.5 M) (44.0 mmol) was added at such a rate
in order not to allow the temperature to exceed -70 °C. After 5-6 h
of stirring at this temperature, 5.1 mL of dry N,N-dimethylformamide
(65.9 mmol) was added so that the temperature remained below -50
°C. After stirring for 45 min at this temperature, the reaction mixture
was poured into HCl/ice (pH < 1) under vigorous stirring. It was
allowed to reach rt overnight and extracted 3× with CH2Cl2. The
combined organic phases were washed twice with water and dried over
MgSO4, and the solvent was removed under reduced pressure after
filtration to give an oil. The oil was recrystallized from a small volume
of AcOEt/ligroin (60/80 °C). The white crystals that formed overnight
in the freezer were filtered off and washed twice with light petroleum
ether and dried in air to give 3.55 g of 5a (89%). In order to obtain an
analytical sample, the oil was submitted to chromatography on silica
using a CH2Cl2 / AcOEt gradient as eluting agent prior to crystalliza-
tion: mp 152 °C; [R]25D ) +114° (CHCl3, c ) 0.01); MS /EI m/z 398
(M+); UV-vis (CHCl3) λmax (ꢀ) ) 250 (52 800), 274 (57 500), 323
(24 300); IR (KBr) 1688 (s, -CdO) cm-1; 1H NMR (400 MHz, CDCl3)
δ 1.09 (t, 6H), 4.12 (m, 4H), 7.18 (d, 2H), 7.51 (d, 2H), 7.69 (dd, J )
1.7, 9 Hz, 2H), 8.13 (d, J ) 9 Hz, 2H), 8.37 (d, 2H), 10.10 (s, 2H);
13C NMR (62.9 MHz, CDCl3) δ 14.62, 64.64, 115.50, 119.58, 123.12,
125.94, 127.88, 131.36, 132.05, 134.86, 137.15, 156.84, 191.85. Anal.
Calcd for C26H22O4: C, 78.37; H, 5.57. Found: C, 78.42; H, 5.58.
(S)-6,6′-Dibromo-2,2′-diethoxy-1,1′-binaphthyl (4a). A 17.2 g
sample of (S)-2,2′-diethoxy-1,1′-binaphthyl (2) (0.05 mol) was dissolved
in 150 mL of CH2Cl2 and stirred at 0 °C (ice bath). A 5.64 mL sample
of bromine (0.11 mol) was added in one portion with stirring and a
stream of nitrogen bubbling through the solution to remove the evolving
HBr. The reaction mixture was stirred for an additional 5 h while the
flask was allowed to warm to rt. The nitrogen flow was stopped and
the yellow solution allowed to stand overnight. A 100 mL sample of
10% NaHSO3 solution was added with vigorous stirring to destroy
excess bromine. The colorless organic layer was separated, washed
with 10% NaHSO3 solution and water, and dried over MgSO4 and the
solvent removed in vacuo after filtration. The remaining oil was
recrystallized from ligroin (80/110 °C) to give 22.27 g (89%) of fine
white needles after washing with light petroleum ether and drying in
air: mp 161-162 °C; [R]25 ) -17.7° (c ) 0.2, CHCl3); MS/FAB+
D
m/z 499 (MH+), 501 (MH+), 503 (MH+); 1H NMR (400 MHz, CDCl3)
δ 1.06 (t, 6H), 4.03 (m, 4H), 6.95 (d, 2H), 7.26 (dd, J ) 2.0, 9 Hz,
2H), 7.42 (d, 2H), 7.84 (d, J ) 9 Hz, 2H), 8.00 (d, 2H); 13C NMR
(62.9 MHz, CDCl3) δ 14.89, 64.96, 116.35, 117.16, 119.93, 126.98,
128.32, 129.34, 129.68, 130.11, 132.41, 154.42. Anal. Calcd for
C24H20Br2O2: C, 57.63; H, 4.03; Br, 31.95. Found: C, 57.45; H, 4.01;
Br, 31.75.
(S)-Dinaphtho[2,1-d:1′,2′-f][1,3]dioxepin-9,14-dicarbaldehyde (5b).
A 4.56 g sample of (S)-9,14-dibromodinaphtho[2,1-d:1′,2′-f][1,3]-
dioxepin (4b) (10.0 mmol) was dissolved in 100 mL of dry THF under
an argon atmosphere. The magnetically stirred solution was cooled to
-78 °C, and 17.6 mL of n-BuLi in n-hexane (2.5 M) (44.0 mmol) was
added at such a rate so as not to allow the temperature to exceed -70
°C. After 5-6 h of stirring at this temperature, 5.1 mL of dry N,N-
dimethylformamide (65.9 mmol) was added so that the temperature
remained below -50 °C. After stirring for 45 min at this temperature,
the reaction mixture was poured into HCl/ice (pH < 1) under vigorous
stirring. It was allowed to reach rt and extracted 3× with CH2Cl2.
The combined organic phases were washed twice with water and dried
over MgSO4, and the solvent was removed under reduced pressure after
filtration. The obtained residue was recrystallized from CH2Cl2/light
petroleum ether and dried under reduced pressure to give 3.18 g (90%)
(S)-9,14-Dibromodinaphtho[2,1-d:1′,2′-f][1,3]dioxepin (4b).
A
mixture of 15.10 g of (S)-6,6′-dibromo-2,2′-dihydroxy-1,1′-binaphthyl
(3a) (34.0 mmol), 17.73 g of dibromomethane (102.0 mmol), 30.0 g
of dry potassium carbonate, and a catalytic amount of NaI in 100 mL
of dry acetone was stirred magnetically and refluxed under anhydrous
conditions (CaCl2 tube) until the reaction was judged to be complete
as monitored by TLC (usually 40 h). After cooling, the reaction mixture
was poured into water and extracted 3× with ether. The combined
organic phases were washed with water. After drying over MgSO4,
the yellow solution was stirred with charcoal, and the solvent was
removed in vacuo after filtration. The obtained white powder was
of a white compound: mp 174-179 °C; [R]25 ) +1045° (c ) 0.02,
D
CHCl3); MS/FAB+ m/z 355 (MH+); UV-vis (CHCl3) λmax (ꢀ) ) 251

6850 J. Am. Chem. Soc., Vol. 118, No. 29, 1996
Deussen et al.
(68 100), 278 (28 900); IR (KBr) 1697 (s, CdO) cm-1; 1H NMR (250
MHz, CDCl3) δ 5.75 (s, 2H), 7.50 (d, 2H), 7.60 (d, 2H), 7.78 (dd, J )
1.7, 9 Hz, 2H), 8.18 (d, J ) 9 Hz, 2H), 8.46 (d, 2H), 10.17 (s, 2H);
13C NMR (62.9 MHz, CDCl3) δ 103.21, 122.26, 123.38, 125.91, 127.41,
130.94, 132.29, 133.34, 134.51, 135.08, 153.83, 191.66. Anal. Calcd
for C23H14O4: C, 77.96; H, 3.98. Found: C, 77.81; H, 4.16.
Calcd for C29H14N4O2: C, 77.33; H, 3.13; N, 12.44. Found: C, 77.27;
H, 3.12; N, 12.59.
3-(6-Butoxy-2-naphthyl)-2-cyanopropenenitrile (6c). A 2.92 g
sample of 6-butoxy-naphthalene-2-carbaldehyde (5c) (12.8 mmol) and
0.90 g of malononitrile (13.6 mmol) were dissolved in 100 mL of dry
CH2Cl2. One drop of piperidine was added, and the reaction mixture
was refluxed under anhydrous conditions (CaCl2 tube) for 3 h. The
CH2Cl2 was removed in vacuo, and the yellow compound was
recrystallized from ethanol to give nice yellow needles. The mother
liquid was concentrated to give a second crop: total yield 2.94 g (83%);
mp 148 °C; MS/EI m/z 276 (M+); UV-vis (CHCl3) λmax (ꢀ) ) 266
(15 200), 287 (14 400), 297 (17 900), 397 (30 100); IR (KBr) 2225 (s,
CN) cm-1; 1H NMR (250 MHz, CDCl3) δ 1.02 (t, J ) 7 Hz, 3H), 1.56
(m, 2H), 1.86 (m, 2H), 4.12 (t, 2H), 7.15 (d, J ) 2.3 Hz, 1H), 7.23
(dd, J ) 2.5, 9 Hz, 1H), 7.78 (d, 1H), 7.80 (s, 1H), 7.82 (d, 1H), 8.04
(dd, 1H), 8.17 (d, J ) 1.3 Hz, 1H); 13C NMR (100.6 MHz, CDCl3) δ
13.71, 19.14, 30.40, 68.04, 106.70, 113.16, 114.27, 120.82, 124.86,
126.24, 127.74, 128.03, 131.20, 134.36, 137.89, 159.46, 160.60. Anal.
Calcd for C18H16N2O: C, 78.23; H, 5.84; N, 10.13. Found: C, 78.07;
H, 5.83; N, 9.96.
6-Butoxynaphthalene-2-carbaldehyde (5c). A 4.03 g sample of
6-bromo-2-butoxynaphthalene (4c) (14.5 mmol) was dissolved in 150
mL of dry THF under an argon atmosphere. The magnetically stirred
solution was cooled to -78 °C, and 6.4 mL of a solution of n-BuLi in
n-hexane (2.5 M) (16.0 mmol) was added at such a rate so as not to
allow the temperature to exceed -60 °C. After 6 h of stirring at this
temperature, 3.0 mL of dry N,N-dimethylformamide (38.7 mmol) was
added so that the temperature remained below -50 °C. After stirring
for 30 min at this temperature, the reaction mixture was allowed to
reach rt within 30 min. It was poured into HCl/ice (pH < 1) and
extracted with CH2Cl2. The organic phase was dried over MgSO4 and
the solvent removed under reduced pressure after filtration. The
compound was redissolved in 100 mL of ether and shaken with 100
mL of NaHSO3 solution (40%) for 4 days. The water phase was washed
3× with ether, and the bisulfite addition product was destroyed by
treatment with 25% sulfuric acid under reflux. After cooling, the
mixture was extracted with ether. The combined organic phases were
washed with water and dried over MgSO4, and the solvent was removed
under reduced pressure after filtration. Recrystallization from EtOH
gave 2.92 g (88%) of a white compound: mp 37 °C; MS/EI m/z 228
(M+); UV-vis (CHCl3) λmax (ꢀ) ) 265 (28 100), 315 (16 700); IR (KBr)
Diethyl (S)-(E,E)-3,3′-(2,2′-Diethoxy-1,1′-binaphthyl-6,6′-diyl)bis-
(2-cyanopropenate) (7a). A 800 mg sample of (S)-2,2′-diethoxy[1,1′-
binaphthyl]-6,6′-dicarbaldehyde (5a) (2.0 mmol) and 498 mg of ethyl
cyanoacetate (4.4 mmol) were dissolved in 40 mL of dry CHCl3. Two
drops of piperidine were added, and the reaction mixture was refluxed
(Dean Stark trap) under anhydrous conditions (CaCl2 tube) for 48 h.
The CHCl3 was removed in vacuo. The remaining oil was dissolved
in a small volume of boiling absolute ethanol, and the solution was
put in a freezer overnight. The light yellow crystals formed were
filtered off and washed twice with ethanol and twice with methanol,
1
1693 (s, CdO) cm-1; H NMR (250 MHz, CDCl3) δ 1.00 (t, J ) 7
Hz, 3H), 1.54 (m, 2H), 1.83 (m, 2H), 4.10 (t, 2H), 7.15 (d, J ) 2.2 Hz,
1H), 7.21 (dd, J ) 2.5, 9 Hz, 1H), 7.76 (d, 1H), 7.86 (d, 1H), 7.90 (dd,
1H), 8.22 (br s, 1H), 10.07 (s, 1H); 13C NMR (62.9 MHz, CDCl3) δ
13.72, 19.15, 31.05, 67.84, 106.69, 120.12, 123.45, 127.57, 127.71,
130.93, 132.13, 134.14, 138.23, 159.73, 191.89. Anal. Calcd for
C15H15O2: C, 78.92; H, 7.07. Found: C, 78.90; H, 7.15.
giving 824 mg (70%) of 7a: mp 168-169 °C; [R]25 ) +695° (c )
D
0.01, CHCl3); MS/EI m/z 588 (M+); UV-vis (CHCl3) λmax (ꢀ) ) 265
(24 000), 306 (45 300), 359 (39 400), 392 (39 100); IR (KBr) 2222
(w, CN), 1724 (s, CdO) cm-1; 1H NMR (400 MHz, CDCl3) δ 1.11 (t,
6H), 1.39 (t, 6H), 4.13 (m, 4H), 4.38 (q, 4H), 7.17 (d, 2H), 7.49 (d,
2H), 7.91 (dd, J ) 1.8, 9 Hz, 2H), 8.08 (d, J ) 9 Hz, 2H), 8.35 (s,
2H), 8.46 (d, 2H); 13C NMR (100.6 MHz, CDCl3) δ 14.11, 14.70, 62.43,
64.70, 101.01, 115.63, 115.92, 119.26, 125.91, 126.08, 126.73, 128.17,
131.46, 134.49, 136.19, 154.83, 156.97, 162.87. Anal. Calcd for
C36H32N2O6: C, 73.45; H, 5.48; N, 4.76. Found: C, 73.44; H, 5.53;
N, 4.82.
(S)-3,3′-(2,2′-Diethoxy-1,1′-binaphthyl-6,6′-diyl)bis(2-cyanopro-
penenitrile) (6a). A 800 mg sample of (S)-2,2′-diethoxy[1,1′-
binaphthyl]-6,6′-dicarbaldehyde (5a) (2.0 mmol) and 291 mg of
malononitrile (4.4 mmol) were dissolved in 40 mL of dry CH2Cl2. Two
drops of piperidine were added, and the reaction mixture was refluxed
under anhydrous conditions (CaCl2 tube) for 20 h. The CH2Cl2 was
removed in vacuo. After chromatography on silica gel (l ) 11 cm,
i.d. ) 4 cm) using CH2Cl2 as an eluent, a yellow solid was obtained
which was recrystallized from absolute ethanol (freezer). The yellow
crystals were filtered off and washed twice with methanol, yielding
811 mg (82%): mp 225 °C; [R]25D ) +1157° (c ) 0.01, CHCl3); MS/
EI m/z 494 (M+); UV-vis (CHCl3) λmax (ꢀ) ) 313 (31 500), 371
(51 500); IR (KBr) 2227 (s, CN), 1617 (s, CdC) cm-1; 1H NMR (400
MHz, CDCl3) δ 1.12 (t, 6H), 4.15 (q, 4H), 7.16 (d, 2H), 7.52 (d, 2H),
7.83 (s, 2H), 7.83 (dd, J ) 1.8, 9 Hz, 2H), 8.09 (d, 2H), 8.34 (d, 2H);
13C NMR (100.6 MHz, CDCl3) δ 14.63, 64.67, 80.31, 113.06, 114.22,
115.77, 118.99, 124.72, 126.35, 127.85, 131.97, 135.03, 136.63, 157.65,
159.28. Anal. Calcd for C32H22N4O2: C, 77.72; H, 4.48; N, 11.33.
Found: C, 77.56; H, 4.48; N, 11.12.
Diethyl (S)-(E,E)-3,3′-(Dinaphtho[2,1-d:1′,2′-f][1,3]dioxepin-9,14-
diyl)bis(2-cyanopropenate) (7b). A mixture of 770 mg of (S)-
dinaphtho[2,1-d:1′,2′-f] [1,3]dioxepin-9,14-dicarbaldehyde (5b) (2.17
mmol), 540 mg of ethyl cyanoacetate (4.77 mmol), and a catalytic
amount of piperidine in 40 mL of CHCl3 was refluxed (Dean Stark
trap) under anhydrous conditions (CaCl2 tube) for 51 h. The mixture
was filtered through a pad of silica, and the solvent was removed under
reduced pressure. Recrystallization from EtOH gave 888 mg (75%)
of a bright yellow solid: mp 257 °C; [R]25 ) +1365° (c) 0.01,
D
CHCl3); MS/FAB+ m/z 545 (MH+)l UV-vis (CHCl3) λmax (ꢀ) ) 283
(34 100), 323 (48 800)l IR (KBr) 2223 (s, CN), 1724 (s, CdO) cm-1
;
1H NMR (400 MHz, CDCl3) δ 1.42 (t, 6H), 4.41 (q, J ) 7 Hz, 4H),
5.75 (s, 2H), 7.51 (d, 2H), 7.58 (d, 2H), 7.98 (dd, J ) 1.9, 9 Hz, 2H),
8.13 (d, J ) 9 Hz, 2H), 8.39 (s, 2H), 8.56 (d, 2H); 13C NMR (100.6
MHz, CDCl3) δ 14.07, 62.64, 102.97, 103.29, 115.50, 122.43, 125.61,
126.12, 127.45, 128.39, 131.13, 132.21, 134.02, 153.88, 154.13, 162.45.
Anal. Calcd for C33H24N2O6: C, 72.79; H, 4.44; N, 5.14. Found: C,
73.06; H, 4.26; N, 5.02.
(S)-3,3′-(Dinaphtho[2,1-d:1′,2′-f][1,3]dioxepin-9,14-diyl)bis(2-cy-
anopropenenitrile) (6b). A mixture of 909 mg of (S)-dinaphtho[2,1-
d:1′,2′-f][1,3] dioxepin-9,14-dicarbaldehyde (5b) (2.57 mmol), 374 mg
of malononitrile (5.66 mmol), and a catalytic amount of piperidine, in
50 mL of CH2Cl2, was refluxed under anhydrous conditions (CaCl2
tube) for 39 h. The solvent was removed under reduced pressure.
Column chromatography on silica (l ) 12 cm, i.d. ) 4 cm) using CH2-
Cl2 as eluent gave a yellow solid. The solid was dissolved in small
volume of CH2Cl2, and petroleum ether was added. The precipitate
was collected using a glass frit and dried under reduced pressure, giving
Ethyl (E)-3-(6-Butoxy-2-naphthyl)-2-cyanopropenate (7c). A 1.50
g sample of 6-butoxynaphthalene-2-carbaldehyde (5c) (6.6 mmol) and
0.96 g of ethyl cyanoacetate (8.5 mmol) were dissolved in 30 mL of
dry CH2Cl2. One drop of piperidine was added, and the reaction
mixture was refluxed under anhydrous conditions (CaCl2 tube) for 3
h. The CH2Cl2 was removed in vacuo, and the yellow compound was
recrystallized from ethanol. The mother liquid was concentrated to
give a second crop: total yield 1.88 g (88%); mp 115 °C; MS/EI m/z
323 (M+); UV-vis (CHCl3) λmax (ꢀ) ) 263 (14 800), 284 (15 200),
293 (17 100), 379 (24 100); IR (KBr) 2220 (s, CN), 1713 (s, CdO),
1582 (s, CdC), 980 (m, dCsHtrans) cm-1; 1H NMR (250 MHz, CDCl3)
δ 1.01 (t, J ) 7 Hz, 3H), 1.41 (t, J ) 7 Hz, 3H), 1.54 (m, 2H), 1.83
(m, 2H), 4.11 (t, 2H), 4.39 (q, 2H), 7.13 (d, J ) 2.3 Hz, 1H), 7.20 (dd,
820 mg (71%) of a yellow solid: mp 233 °C; [R]25 ) +1845° (c )
D
0.01, CHCl3); MS/FAB+ m/z 451 (MH+); UV-vis (CHCl3) λmax (ꢀ) )
270 (25 300), 287 (32 000), 305 (33 700), 339 (50 300); IR (KBr) 2228
(s, CN), 1617 (s, CdC) cm-1; 1H NMR (400 MHz, CDCl3) δ 5.77 (s,
2H), 7.48 (d, 2H), 7.62 (d, 2H), 7.90 (dd, J ) 1.9, 9 Hz, 2H), 7.90 (s,
2H), 8.15 (d, J ) 9 Hz, 2H), 8.44 (d, 2H); 13C NMR (100.6 MHz,
CDCl3) δ 82.58, 103.37, 112.59, 113.70, 123.00, 124.87, 125.51,
127.68, 127.87, 130.88, 132.58, 134.38, 134.53, 154.56, 158.82. Anal.

Bis-dipolar 6,6′-Disubstituted Binaphthol DeriVatiVes
J. Am. Chem. Soc., Vol. 118, No. 29, 1996 6851
ArH, 1H), 7.76 (d, ArH, 1H), 7.82 (d, ArH, 1H), 8.16 (dd, ArH, J )
1.8, 9 Hz, 1H), 8.29 (br s, ArH, 1H), 8.34 (s, 1H); 13C NMR (100.6
MHz, CDCl3) δ 13.72, 14.11, 31.05, 62.41, 67.90, 100.73, 106.55,
115.99, 120.31, 125.88, 126.69, 127.64, 127.97, 130.91, 134.12, 137.26,
154.95, 159.87, 162.87. Anal. Calcd for C18H16N2O: C, 74.28; H,
6.55; N, 4.33. Found: C, 74.01; H, 6.47; N, 4.41.
magnetically for 20 h. The mixture was hydrolyzed with 300 mL of
dilute HCl. The precipitate that formed was collected by filtration (glass
frit) and washed thoroughly with water. The obtained solid was dried,
dissolved in CH2Cl2, and filtered through a pad of silica (1 cm). After
evaporation of most of the solvent under reduced pressure, recrystal-
lization from CH2Cl2/ether gave 700 mg (88%) of fine orange
crystals: mp 273 °C; [R]25D ) +776° (c ) 0.002, CHCl3); MS/FAB+
m/z 637 (MH+); UV-vis (CHCl3) λmax (ꢀ) ) 253 (45 500), 297
(38 200), 397 (54 500); IR (KBr) 1618 (m, CdC), 966 (m, CHdCHtrans),
1515 (s, NO), 1338 (s, NO) cm-1; 1H NMR (400 MHz, CDCl3) δ 1.09
(t, J ) 7 Hz, 6H), 4.08 (m, 4H), 7.13 (d, Jtrans ) 16.3 Hz, 2H), 7.15 (d,
2H), 7.40 (d, Jtrans ) 16.3 Hz, 2H), 7.45 (d, 2H), 7.48 (dd, J ) 1.7, 9
Hz, 2H), 7.62 (br d, 4H), 7.94 (d, 2H), 7.97 (d, J ) 9 Hz, 2H), 8.20
(br d, 4H); 13C NMR (100.6 MHz, CDCl3) δ 14.87, 64.97, 115.92,
120.25, 123.49, 124.05, 125.38, 125.99, 126.57, 128.05, 129.05, 129.59,
131.29, 133.41, 134.20, 144.01, 146.48, 155.01. Anal. Calcd for C40-
H32N2O6: C, 75.46; H, 5.07; N, 4.40. Found: C, 75.29; H, 5.11; N,
4.20.
(S)-(E,E)-3,3′-(2,2′-Diethoxy-1,1′-binaphthyl-6,6′-diyl)dipro-
penenitrile (8a). A 1019 mg sample of (S)-2,2′-diethoxy[1,1′-
binaphthyl]6,6′-dicarbaldehyde (5a) (2.56 mmol) and 1087 mg of
diethyl cyanomethylphosphonate (6.14 mmol) were dissolved in 90 mL
of dry DME under a nitrogen atmosphere. A 300 mg portion of sodium
hydride (80% in mineral oil) (10.0 mmol) was added in small portions
at 0 °C to the magnetically stirred mixture. The reaction mixture was
slowly allowed to reach rt and stirred for 12 h. The mixture was
hydrolyzed with 300 mL of dilute hydrochloric acid. The precipitate
that formed was collected using a glass frit and washed thoroughly
with water. After drying in air, it was recrystallized from a small
volume of EtOH (freezer) to give 603 mg (53%) of 8a: mp 155-158
°C; [R]25 ) +455° (c ) 0.01, CHCl3); MS/FAB+ m/z 445 (MH+);
(S)-(E,E)-9,14-Bis[2-(methylsulfonyl)vinyl]dinaphtho[2,1-d:1′,2′-
f] [1,3]dioxepin (10b). A 983 mg sample of diethyl [methylsulfonyl)-
methyl]phosphonate (4.27 mmol) and 630 mg of (S)-dinaphtho)[2,1-
d:1′,2′-f][1,3]dioxepin-9,14-dicarbaldehyde (4b) (1.78 mmol) were
dissolved in dry DME (60 mL) under a nitrogen atmosphere. A 384
mg sample of sodium hydride (12.8 mmol) was added in portions at 0
°C to the magnetically stirred mixture. The reaction mixture was slowly
allowed to reach rt and stirred for 3 days. The mixture was cautiously
hydrolyzed with dilute hydrochloric acid (600 mL) and extracted 3×
with CH2Cl2. The combined organic phases were washed with water
and dried over MgSO4, and most of the solvent was removed in vacuo
after filtration. Ether was added, and the white precipitate that formed
was collected using a glass frit and washed with a small volume of
ether and dried in high vacuum to give 514 mg (57%) of a white
D
UV-vis (CHCl3) λmax (ꢀ) ) 260 (39 500), 288 (58 200), 334 (41 000);
1
IR (KBr) 2215 (s, CN), 1616 (s, CdC), 966 (m, dCHtrans) cm-1; H
NMR (400 MHz, CDCl3) δ 1.08 (t, J ) 7 Hz, 6H), 4.08 (m, 4H), 5.84
(d, Jtrans ) 16.5 Hz, 2H), 7.08 (d, 2H), 7.28 (dd, J ) 1.8, 9 Hz, 2H),
7.45 (d, 2H), 7.51 (d, Jtrans ) 16.5 Hz, 2H), 7.88 (d, 2H), 7.98 (d, 2H);
13C NMR (100.6 MHz, CDCl3) δ 14.76, 64.79, 94.87, 115.86, 118.45,
119.74, 122.47, 126.13, 128.44, 128.68, 129.91, 130.35, 135.18, 150.46,
155.83. Anal. Calcd for C30H24N2O2: C, 81.06; H, 5.44; N, 6.30.
Found: C, 81.31; H, 5.68; N, 5.88.
(S)-(E,E)-3,3′-(Dinaphtho[2,1-d:1′,2′-f][1,3]dioxepin-9,14-diyl)-
dipropenenitrile (8b). A 1000 mg sample of (S)-dinaphtho)[2,1-d:
1′,2′-f][1,3]dioxepin-9,14-dicarbaldehyde (4b) (2.82 mmol) and 1199
mg of diethyl (cyanomethyl)phosphonate (6.77 mmol) were dissolved
in 40 mL of dry DME under a nitrogen atmosphere. A 305 mg portion
of sodium hydride (80% in mineral oil) (10.17 mmol) was added in
small portions at 0 °C to the magnetically stirred mixture. The reaction
mixture was slowly allowed to reach rt and stirred for 24 h. It was
hydrolyzed with 300 mL of dilute hydrochloric acid. The precipitate
that formed was collected using a glass frit and washed thoroughly
with water. After drying in air, the compound was dissolved in CH2-
Cl2 and filtered through a pad of silica. After evaporation of most of
the solvent in vacuo, light petroleum ether was added, and the white
precipitate was filtered off (glass frit) and dried in high vacuum to
powder: mp 206 °C dec; [R]25 ) +980° (c ) 0.01, CHCl3); MS/
D
FAB+ m/z 507 (MH+); UV-vis (CHCl3) λmax (ꢀ) ) 263 (65 900), 300
(42 100); IR (KBr) 1620 (m, CdC), 1310 (s, -SO2-), 1133 (s, -SO2-
1
), 970 (m, dCsHtrans) cm-1; H NMR (400 MHz, CDCl3) δ 3.06 (s,
6H), 5.73 (s, 2H), 6.98 (d, Jtrans ) 15.4 Hz, 2H), 7.43 (dd, J ) 1.7, 9
Hz, 2H), 7.46 (d, 2H), 7.56 (d, 2H), 7.79 (d, Jtrans ) 15.4 Hz, 2H),
8.05 (d, J ) 9 Hz, 2H), 8.07 (d, 2H); 13C NMR (100.6 MHz, CDCl3)
δ 43.27, 103.22, 122.22, 123.59, 125.78, 126.37, 127.51, 128.80,
131.35, 131.40, 133.15, 143.37, 152.86. Anal. Calcd for C27H22-
O3S2: C, 64.02; H, 4.38; S, 12.66. Found: C, 63.95; H, 4.31; S, 11.96.
give 655 mg (58%) of 8b: mp 324 °C; [R]25 ) +1379° (c ) 0.01,
(S)-(E,E)-3,3′-(Dinaphtho[2,1-d:1′,2′-f][1,3]dioxepin-9,14-diyl) dipro-
penal (11b). A 610 mg sample of sodium hydride (80% suspension
in mineral oil) (20.32 mmol) was added in portions to a mixture of
6.32 g of diethyl [2-(cyclohexylamino)vinyl]phosphonate (GC 84%)
(20.32 mmol) and 3.00 g of (S)-dinaphtho[2,1-d:1′,2′-f][1,3]dioxepin-
9,14-dicarbaldehyde (4b) (8.47 mmol) dissolved in 60 mL of dry
dimethoxyethane under an inert atmosphere at 0 °C. The suspension
was slowly allowed to reach rt and stirred for 24 h. The mixture was
cautiously hydrolyzed with 500 mL of water and extracted 3× with
CH2Cl2. The solvent of the combined organic phases was evaporated
in vacuo. An oil was obtained, which was redissolved in 100 mL of
CH2Cl2 and shaken with a 200 mL acetic acid-sodium acetate buffer
(1 M) for 24 h. The organic phase was separated, washed 2× with
10% KHCO3 solution and water, and dried over MgSO4 and the solvent
removed in vacuo after filtration. The obtained solid was purified by
column chromatography on silica (l ) 11 cm, i.d. ) 4 cm) using a
mixture of ligroin (60:80)/AcOEt (1:1, v:v) as eluent to give 2.10 g
(61%) of a solid. An analytical sample was obtained after drying at
100 °C overnight: mp 152-155 °C; [R]D ) +1444° (c)0.02, CHCl3);
MS/EI m/z 406 (M+); UV-vis (CHCl3) λmax (ꢀ) ) 275 (47 500), 316
D
CHCl3); MS/FAB+ m/z 401 (MH+); UV-vis (CHCl3) λmax (ꢀ) ) 268
(71 200), 308 (58 200), 362 (6800); IR (KBr) 2216 (s, CN), 1620 (s,
1
CdC), 963 (s, dCsHtrans) cm-1; H NMR (400 MHz, CDCl3) δ 5.72
(s, 2H), 5.94 (d, Jtrans ) 16.5 Hz, 2H), 7.39 (dd, J ) 1.8, 9 Hz, 2H),
7.43 (d, 2H), 7.54 (d, 2H), 7.55 (d, Jtrans ) 16.5 Hz, 2H), 7.96 (d, 2H),
8.02 (d, 2H); 13C NMR (100.6 MHz, CDCl3) δ 96.64, 103.12, 118.10,
122.34, 122.61, 125.89, 127.59, 130.06, 130.36, 131.41, 131.48, 133.16,
149.95, 152.89. Anal. Calcd for C27H16N2O2: C, 80.99; H, 4.03; N,
7.00. Found: C, 80.79; H, 4.15; N, 6.71.
Diethyl (4-Nitrobenzyl)phosphonate. A mixture of 25.0 g of
4-nitrobenzyl bromide (Aldrich) (0.12 mol) and 39.88 g of triethyl
phosphite (0.24 mol) was slowly heated over a 3 h period to 150 °C,
and this temperature was maintained for 24 h. The ethyl bromide
evolved was trapped with a condenser and a receiver cooled in an ice
bath. The residual oil was fractionally distilled under high vacuum to
give 23.4 g (71%) of an oil: bp 160-161 °C, 0.03 mmHg (lit.14 bp
1
148-153 °C, 0.1 mmHg); GC 100%; MS/EI m/z 273(M+); H NMR
(90 MHz, CDCl3) δ 1.28 (t, J ) 7 Hz, 6H), 3.32 (d, JP,H ) 22.6 Hz,
2H), 4.08 (m, 4H), 7.50 (dd, 2H), 8.18 (dd, 2H); 31P NMR (36.4 MHz,
CDCl3) δ 23, 79 (s).
(52 300); IR (KBr) 1677 (s, CdO), 1621 (s, C)C), 978 (s, dCsHtrans
)
)
1
cm-1; H NMR (400 MHz, CDCl3) δ 5.73 (s, 2H), 6.80 (dd, Jtrans
(S)-(E,E)-2,2′-Diethoxy-6,6′-bis(4-nitrostyryl)-1,1′-binaphthyl (9a).
A 882 mg sample of diethyl (4-nitrobenzyl)phosphonate (3.23 mmol)
was dissolved in 50 mL of dry dimethoxyethane under an inert
atmosphere. A 250 mg portion of sodium hydride (80% in mineral
oil) (8.33 mmol) was added at 0 °C, and the suspension was stirred
magnetically for 30 min at this temperature. To the suspension was
added 500 mg (S)-2,2′-diethoxy-1,1′[binaphthyl]-6,6′-dicarbaldehyde
(5a) (1.25 mmol) dissolved in 20 mL of dry dimethoxyethane, and the
reaction mixture was allowed to warm slowly to rt while being stirred
15.9 Hz, 2H), 7.49 (d, 2H), 7.52 (dd, J ) 1.8 Hz, 2H), 7.55 (d, 2H),
7.64 (d, Jtrans ) 15.9 Hz, 2H), 8.06 (d, J ) 9 Hz, 2H), 8.11 (d, 2H),
9.77 (d, J ) 8 Hz, 2H); 13C NMR (100.6 MHz, CDCl3) δ 103.19,
122.08, 123.92, 125.85, 127.42, 128.79, 130.83, 130.83, 131.35, 131.50,
133.17, 151.91, 152.78, 193.34. Anal. Calcd for C27H18O4: C, 79.79;
H, 4.46. Found: C, 79.47; H, 4.48.
(S)-(E,E)-5,5′-(Dinaphtho[2,1-d:1′,2′-f][1,3]dioxepin-9,14-diyl)bis-
(2-cyanopenta-2,4-dienenitrile) (12b). A 519 mg sample of (S)-(E,E)-

6852 J. Am. Chem. Soc., Vol. 118, No. 29, 1996
Deussen et al.
3,3′-(dinaphtho[2,1-d:1′,2′-f][1,3]dioxepin-9,14-diyl)dipropenal (11b)
(1.28 mmol) and 186 mg of malononitrile (2.82 mmol) were dissolved
in 50 mL of dry CH2Cl2. A 7 mg portion of piperidine was added,
and the reaction mixture was refluxed under anhydrous conditions
(CaCl2 tube) for 19 h. The CH2Cl2 was removed in vacuo. After
chromatography on silica gel (l ) 10 cm, i.d. ) 4 cm) using CH2Cl2
as an eluent, the compound was dissolved in a small volume of CH2-
Cl2, and light petroleum ether was added. The precipitate was filtered
off using a glass frit and dried under reduced pressure to give 420 mg
(65%) of a bright orange powder: mp 185-187 °C; [R]25D ) +3184°
(c ) 0.005, CHCl3); MS/FAB+ m/z 503 (MH+); UV-vis (CHCl3) λmax
(ꢀ) ) 313 (31 500), 371 (51 500); IR (KBr) 2226 (s, CN), 1603 (s,
127.63, 130.84, 131.42, 131.49, 131.90, 133.48, 149.49, 153.31, 159.55.
Anal. Calcd for C33H18N4O2: C, 78.87; H, 3.61; N, 11.15. Found:
C, 78.75; H, 3.59; N, 11.17.
Acknowledgment. H.-J.D. thanks the Gottlieb Daimler- und
Karl Benz-Stiftung for a Ph.D. Grant. E.H. is a research
assistant and K.C. a senior research associate of the Belgian
National Fund for Scientific Research. C.B. obtained a research
grant from the Flemish Executive (IWT). We would like to
express our gratitude to Professor E. W. Meijer for inspiring
discussions. This work is partly supported by the Belgian Prime
Minister’s Office of Science Policy “InterUniversity Attraction
pole in Supramolecular Chemistry and Catalysis” (Grant IUAP
16) and the Flemish Government’s Grant GOA 95/1. We thank
the Danish Material Research Program (MUP) for financial
support.
1
CdC), 980 (s, dCsHtrans) cm-1; H NMR (400 MHz, CDCl3) δ 5.75
(s, 2H), 7.33 (dd, 2H), 7.44 (d, Jtrans ) 15.6 Hz, 2H), 7.46 (d, 2H),
7.56 (dd, J ) 1.8, 9 Hz, 2H), 7.57 (d, 4H), 7.65 (d, J ) 11.4 Hz, 2H),
8.07 (d, J ) 9 Hz, 2H), 8.12 (d, 2H); 13C NMR (100.6 MHz, CDCl3)
δ 82.95, 103.28, 111.58, 113.40, 122.39, 122.62, 123.82, 125.83,
JA960076O