Synthesis, characterization, and DFT studies of a novel azo dye derived from racemic or optically active binaphthol

Article abstract of DOI:10.1016/j.tet.2008.09.104

We present a new azo reactive dye from racemic or optically active BINOL. This dye was characterized by UV-vis, FTIR, mass, ¹H NMR, and ¹³C NMR spectroscopic techniques and elemental analysis. The structure and spectrometry of this azo dye have been investigated theoretically by performing HF and DFT levels of theory using the standard 6-31G^* basis set. The optimized geometries and calculated vibrational frequencies are evaluated via comparison with experimental values. The vibrational spectral data obtained from solid phase FTIR spectra are assigned based on the results of the theoretical calculations. The theoretical electronic absorption spectra have been calculated using CIS, TD-DFT, and ZINDO methods. In addition, a good agreement between calculated and experimental NMR data is observed.

Full text of DOI:10.1016/j.tet.2008.09.104

Tetrahedron 64 (2008) 11776–11782
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Synthesis, characterization, and DFT studies of a novel azo dye derived from
racemic or optically active binaphthol
,
c
Abbas Teimouri a, Alireza Najafi Chermahini b , Mohammad Emami
*
a Payame Noor University (PNU), Isfahan, PO Box 81395-671, Iran
b Department of Chemistry, Yasouj University, Yasouj, Iran
c Department of Chemistry, Shahid Beheshti University, Tehran, Iran
a r t i c l e i n f o
a b s t r a c t
Article history:
We present a new azo reactive dye from racemic or optically active BINOL. This dye was characterized by
UV–vis, FTIR, mass, 1H NMR, and 13C NMR spectroscopic techniques and elemental analysis. The structure
and spectrometry of this azo dye have been investigated theoretically by performing HF and DFT levels of
Received 19 April 2008
Received in revised form
12 September 2008
Accepted 25 September 2008
Available online 11 October 2008
theory using the standard 6-31G basis set. The optimized geometries and calculated vibrational fre-
*
quencies are evaluated via comparison with experimental values. The vibrational spectral data obtained
from solid phase FTIR spectra are assigned based on the results of the theoretical calculations. The
theoretical electronic absorption spectra have been calculated using CIS, TD-DFT, and ZINDO methods. In
addition, a good agreement between calculated and experimental NMR data is observed.
Ó 2008 Elsevier Ltd. All rights reserved.
Keywords:
Diazotization
Diazocoupling
Binaphthol
DFT
Ab initio
1. Introduction
(R)-BINOL pendant groups by Ikegami et al.7 Asymmetric synthesis
of macrocyclic BINOL dimers was reported by Harada et al., Cram
Azo dyes are compounds that contain azo groups linked to
methine or aromatic sp2-hybridized C-atoms. The formation of
diazotizing reagent starts with protonation of nitrous acid under
strongly acidic conditions, and azo coupling occurs at low
temperature in the presence of nucleophilic coupling components.
The reactivity of a nucleophilic substrate increases with increase in
phenolates and amines.1 1,10-Binaphthalene-2,20-diol (BINOL) is
one of the best-known representatives of axially chiral C2-sym-
metric molecules; BINOL and its derivatives are among the most
widely used ligands for a variety of asymmetric reactions. In-
terconvertible conformational isomers resulting from a rotation
et al., and Diederich et al.8 Recent fields of applications of BINOL
derivatives are the synthesis of HIV-protease inhibitors9,10 and
chiral stationary phases.11
Only a few theoretical works dealing with BINOL were found in
the literature. Based on DFT calculations, Sahnoun et al. reported
the mechanism of the isomerization of 1,10-bi-2-naphthol
(BINOL)12 and Havlas et al. presented the racemization barriers of
BINOL.13
As part of our ongoing research program into the synthesis and
theoretical studies of azo dyes,14–18 we report the synthesis of
a new azo reactive dye by the reaction of p-diazonium benzene
sulfonyl azide with racemic or optically active BINOL as coupling
component in the presence of a base. These interesting compounds
have both the character of BINOL as an auxiliary and as an
asymmetric ligand for complexation. In addition, these compounds
are reactive and can be used in other reactions.
around their
d-bond are known as ‘atropisomers’. BINOL and its
derivatives have been extensively used to provide
a
chiral
environment in asymmetric synthesis,2 chiral ligands,3 and in
polymer synthesis.4 Application of 1,10-binaphthalene-2,20-diol
(BINOL) and its derivatives in asymmetric catalysis has been
broadly studied.5 Enantiomerically pure BINOL is easily obtainable
by resolution of the low-cost racemate and is one of the most used
chiral auxiliaries for asymmetric synthesis.6 New insoluble chiral
catalysts were prepared from non-cross-linked copolymers with
2. Result and discussion
2.1. Computational details
The molecular structures of 6-[4-(azidosulfonyl)phenyl]-1-di-
azenyl-1,10-binaphthalen-2,20-diol in the ground state have been
already optimized by the Hartree–Fock (HF) method, Becke 3–Lee–
* Corresponding author. Tel./fax: þ98 7412223048.
E-mail address: najafi@mail.yu.ac.ir (A.N. Chermahini).
0040-4020/$ – see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2008.09.104

A. Teimouri et al. / Tetrahedron 64 (2008) 11776–11782
11777
O
C
O
C
O
S Cl
O
O
S N3
O
NaN3
HCl
NH
H3C
NH
H3C
O
O
HCl/NaNO2
Binaphthol
Cl N2
S N3
O
H2N
S N3
O
H2O,KOH
13 12
O
S
14
11
5
9
4
N3
N N
3
6
7
O
15 16
10
8
2
OH
OH
1
8'
9'
1'
7'
6'
2'
3'
10'
5'
4'
Scheme 1. Chemical structure of compound 1.
Table 1
Specific rotations of the new BINOL dye derivatives
Figure 1. The structure of compound 1, optimization has been performed by the
B3LYP/6-31G method.
*
Compound
Mp
Specific rotationa
R,S
R
S
213–215
199–201
194–196
d
þ54.7
ꢀ55.1
Initial geometry generated from standard geometrical parame-
ters was minimized without any constraint in the potential energy
a
25
[a
]
(c 0.5, acetone).
D
surface at Hartree–Fock level, adopting the standard 6-31G basis
*
set. This geometry was then re-optimized at B3LYP level, using the
same basis set for better description. The optimized structural pa-
rameters were used in the vibrational frequency calculations at the
HF and DFT levels to characterize all the stationary points as min-
ima. The vibrationally averaged nuclear positions of this compound
were used then for the harmonic vibrational frequency calculations
resulting in an IR frequency together with the intensities. The
vibrational frequencies for these species were calculated using
Yang–Parr (B3LYP) functionals,20,21 and by combining the results of
the GaussView program22 with symmetry. Vibrational frequency
calculations were made with a high degree of accuracy as well.
There is always some ambiguity in defining internal coordination.
However, the defined coordinates form a complete set and match
quite well with the motions observed using the GaussView pro-
gram. Finally, the calculated vibrational frequencies of normal
modes, the visible absorption maxima, NMR, and thermodynamic
properties were also calculated with these methods. These
calculations were performed at HF and DFT (B3LYP functionals)
levels using the Gaussian 03W program package.23
these methods and then scaled by 0.8991 and 0.9663 for HF/6-31G
*
24
and B3LYP/6-31G
*
.
CIS, ZNIDO, and the time-dependent density
functional theory (TD-DFT) calculations of electronic absorption
spectra were also performed on the optimized structure.
In order to obtain further Supplementary data for the postulated
structure, we calculated the 1H and 13C NMR chemical shifts for this
structure by DFT GIAO25 model at B3LYP/6-311þG(2d,p) level26 on the
Table 2
structure of the optimized compound by the B3LYP/6-31G method.
*
Selected bond distances (Å), bond angles (ꢁ) and dihedral angles (ꢁ) of 1
Parameters
HF/6-31G
*
B3LYP/6-31G
*
Parameters
HF/6-31G
*
B3LYP/6-31G
*
2.2. Molecular structure of azo dyes
Bond lengths (Å)
S–C14
1.7639
1.3853
1.3824
1.3875
1.3919
1.3799
1.3894
1.4209
1.4113
1.3594
1.7834
1.3969
1.3906
1.4031
1.4067
1.3881
1.4006
1.4175
1.4046
1.3854
C6–C7
C7–C8
C8–C10
C5–C9
C2–O
C1–C10
C20–O
N]N
1.4221
1.3534
1.4292
1.4164
1.3485
1.4976
1.3522
1.2213
1.6859
1.4268
1.3690
1.4304
1.4129
1.3626
1.4949
1.3681
1.2654
1.7769
The general route for the synthesis of compound 1 is shown in
Scheme 1 (Table 1). The optimized structural parameters of this
C14–C15
C15–C16
C16–C11
C11–C12
C12–C13
C13–C14
C11–N
C6–N
C6–C5
S–N
Bond angles (ꢁ)
C10–C1–C10
C2–C1–C10
C90–C10–C1
C20–C10–C1
C7–C6–N
C12–C11–N
C16–C11–N
O–C2–C3
121.5
119.8
121.3
119.7
124.1
124.3
115.3
119.8
121.6
119.6
121.4
119.5
124.7
124.7
115.3
120.6
O–C20–C10
118.8
122.2
118.0
122.2
121.6
122.0
121.6
119.1
119.0
C10–C90–C80
C40–C100–C50 121.3
C1–C10–C8
C4–C9–C5
C13–C14–S
C15–C14–S
122.1
121.3
119.5
119.1
Dihedral angles (ꢁ)
C10–C1–C10–C20 ꢀ91.5
ꢀ91.0
ꢀ91.1
179.7
104.6
81.3
C13–C14–S–N ꢀ99.1
ꢀ98.5
0.6
0.7
C2–C1–C10–C90 ꢀ91.7
O–C2–C1–C10
O–C20–C10–C1
0.8
0.7
C11–N]N–C6
C14–S–N]N
C15–C14–S–N
179.9
98.1
80.7
Figure 2. The experimental FTIR spectra of the compound 1.

11778
100
A. Teimouri et al. / Tetrahedron 64 (2008) 11776–11782
160
140
120
100
80
80
60
40
20
0
60
40
20
0
B3LYP/6-31G*
HF/6-31G*
0
346 692 1038 1384 1730 2076 2422 2769 3115 3461 3807
Frquencies (cm-1)
3900
3400
2900
2400 1900
Frequencies (cm-1)
1400
900
400
Figure 5. Comparison of corrected frequencies (cmꢀ1) normalized IR intensities at
B3LYP/6-31G level of compound.
*
Figure 3. Predicted spectra of compound 1 at B3LYP/HF/6-31G level.
*
2.3. Assignments of vibrational frequencies
compound calculated by ab initio and DFT/B3LYP levels with the 6-
31G* basis set are listed in Table 2 and the optimized configuration
is shown in Figure 1. Since the crystal structure of this compound is
not available, the optimized structure can only be compared with
the other similar systems for which the configurations have been
optimized. For example, the optimized bond lengths of C–C in the
Vibrational spectroscopy is used extensively in organic
chemistry for the identification of functional groups of organic
compounds, the study of molecular conformations, reaction ki-
netics, etc. Assignment of complex systems can be proposed on the
basis of frequency agreement between the computed harmonics
and the observed fundamental modes. The observed experimental
FTIR spectra and the theoretically predicted IR spectra are shown in
Figures 2–5. The resulting vibrational wave numbers for the opti-
mized geometry and the proposed assignments are given in Table 3.
The vibrational spectral data obtained from the solid phase FTIR
spectra are assigned based on the results of the normal coordinate
calculations. The observed and the calculated spectra are found to
be in good agreement with each other. Based on the comparison
between the calculated and experimental results, assignments of
fundamental modes were carried out. The assignment of the ex-
perimental frequencies is based on the observed band frequencies
naphthyl ring fall in the range 1.3690–1.4304 Å for the HF/6-31G
*
method and 1.3534–1.4222 Å for the B3LYP/6-31G method, which
*
are in good agreement with a similar molecular structure, 1.385–
1.439 Å.12 Moreover, the optimized bond lengths of C–C in the
phenyl ring fall in the range 1.3799–1.3894 Å for the HF/6-31G
*
and
1.3881–1.4068 Å for the B3LYP/6-31G method, which are in good
*
agreement with the molecular structure of a phenyl ring with an
arensulfonyl group (1.385–1.400 Å).27
The HF optimized C11–N and C6–N bond lengths are 1.4209 Å
and 1.4113 Å and for the B3LYP/6-31G
respectively. For Cring–S bond, the optimized lengths are 1.7640 Å
for the HF/6-31G method and 1.7835 Å for the B3LYP/6-31G
*
are 1.4176 Å and 1.4046 Å,
*
*
method (see Table 2). Based on the above comparison, although
there are some differences between our values and the literature
data, the optimized structural parameters can reproduce the
literature ones, and they are the bases for further discussion. With
respect to the dihedral angle between the two naphthyl planes, it
has been previously reported that there are two minima: one about
90ꢁ and another is near 60ꢁ (see Ref. 13 and references therein).
Interestingly, DFT and HF calculations only showed that the
C10C1C10C20 dihedral angles are ꢀ91.0ꢁ and ꢀ91.6ꢁ, respectively.
Table 3
Comparison of the observed and calculated vibrational spectra of compound 1
HF (I)
B3LYP (I)
Exp
Assignment
1
2
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
20
21
22
23
24
25
26
27
28
3666(31.3254)
3662(41.0163)
3154(81.322)
3138(49.4995)
2164(225.519)
1777(64.2301)
1694(228.188)
1618(100.655)
1573(300.476)
1440(671.019)
1397(57.8738)
1319(44.0809)
1164(45.8744)
1159(45.736)
1076(26.3607)
982(25.2746)
952(24.44)
903(330.226)
856(144.542)
809(19.466)
768(36.7133)
695(300.959)
651(166.765)
607(73.9234)
506(53.2987)
403(17.3051)
3755(59.2998)
3751(110.21)
3236(0.4601)
3206(39.0718)
2137(223.739)
1647(37.842)
1565(44.5621)
1523(7.1679)
1482(30.4452)
1383(77.7509)
1331(98.7896)
1314(72.4877)
1201(4.6582)
1195(39.0304)
1085(55.5398)
1002(0.3048)
975(30.2545)
921(9.7702)
874(26.8148)
807(22.6099)
777(3.27)
709(98.206)
669(107.557)
623(19.3551)
514(17.2638)
423(5.6278)
3411
3396
3098
3061
2126
1582
1532
1507
1451
1379
1339
1253
1226
1185
1168
1143
987
893
835
787
757
685
634
588
504
n(OH)
n(OH)
n(CH)
n(CH)
N3
nring
nring
n(N]N)
nring
nsym.(N3)
nasym.(SO2)
700
600
500
400
300
200
100
0
n
p
d
p
(CN)
(CH)
(OH)
(CS)þ
p
(CN)
(CN)
p(CH)
nsym.(SO2)þ
n
p
p
(SN)þ
(CH)þ
p
(CN)
dring
dring
dring
p
p
dring
(OH)
(CS)þ
p(CN)
0
321 643 964 1286 1607 1929 2250 2572 2893 3214 3536
Frequencies (cm-1)
d(SO2)
417
pringþu(SO2)
Figure 4. Comparison of corrected frequencies in cmꢀ1 normalized IR intensities at
HF/6-31G level of compound 1.
n
, stretching; d, in-plane bending; p, out-of-plane bending; u, wagging. Subscript:
*
asym., asymmetric; sym., symmetric.

A. Teimouri et al. / Tetrahedron 64 (2008) 11776–11782
11779
Exp
Table 5
4000
3500
3000
2500
2000
1500
1000
500
Experimental and calculated 13C NMR chemical shifts (ppm) of compound 1
B3LYP/6-31G*
HF/6-31G*
R2 = 0.9937
R2 = 0.9951
Carbon
HF
B3LYP
C11
C2
C20
C6
168.8
167.1
167.2
159.5
151.5
142.6
142.3
140.7
140.0
140.6
137.6
136.9
137.6
138.0
136.6
134.1
135.2
134.8
133.4
132.4
131.3
133.8
133.6
128.3
128.1
125.6
152.3
149.5
149.7
143.9
138.0
128.1
128.8
127.1
126.4
126.1
123.4
123.1
123.0
123.5
122.1
121.6
121.7
120.3
119.9
119.9
117.7
118.1
118.0
113.6
113.5
110.0
159.2
155.1
155.1
149.9
143.7
133.5
133.4
131.7
130.7
130.2
128.9
128.9
128.5
128.5
127.4
127.0
126.1
125.8
124.6
124.6
123.9
122.7
122.7
119.5
119.5
116.2
C14
C10
C90
C50
C100
C9
C4
0
0
500
1000
150
0
2
Cal.
00
0
2500
300
0
3
50
0
4
000
C40
C13
C15
C50
C70
C80
C80
C12
C16
C60
C1
Figure 6. Graphic correlation between the experimental and the theoretical fre-
quencies obtained by B3LYP/6-31G method and HF/6-31G method.
*
*
in the infrared spectra of this species confirmed by establishing one
to one correlation between observed and theoretically calculated
frequencies.
C10
C3
The calculated frequencies are slightly higher than the observed
values for the majority of the normal modes. Two factors may be
responsible for the discrepancies between the experimental and
computed spectra of azo dyes. The first is caused by the environ-
mental conditions and the second one arises from the fact that the
experimental value is an anharmonic frequency while the calcu-
lated value is a harmonic frequency.28 Assignment of all the
vibrational bands has been carried out on the basis of the DFT
calculations. A linearity between the experimental and calculated
wave numbers (i.e., for the whole spectral range considered) can be
estimated by plotting the calculated versus experimental wave
numbers (Fig. 6). The values of the correlation coefficients indicate
good linearity between the calculated and experimental wave
numbers (correlation coefficients of 0.899, 0.999).
C30
C7
Table 6
Experimental and calculated 13C NMR chemical shifts (ppm) of compound 1
Poroton
HF
B3LYP
Exp
HOH
HOH
H5
H7
H8
8.23
8.48
9.11
7.89
6.84
6.45
8.02
8.15
8.64
7.70
7.87
8.23
6.63
7.04
7.14
6.58
8.26
8.86
8.87
7.99
7.89
7.83
7.63
7.31
7.43
7.93
7.49
7.36
7.42
7.32
7.23
7.03
6.99
7.54
9.19
9.19
8.14
8.08
7.97
7.74
7.74
7.86
7.86
7.68
7.57
7.57
7.48
7.31
7.19
7.03
7.03
The naphthyl ring modes predominantly involve C–C bonds
and the vibrational frequency is associated with the C–C stretching
modes of the carbon skeleton. The C–C stretching modes, known
as semi-circle stretching, predicted at 1510–1660 cmꢀ1 are in
excellent agreement with the experimental observation of the
Hphenyl
Hphenyl
Hphenyl
Hphenyl
H50
H4
FTIR value at 1508–1582 cmꢀ1
755 cmꢀ1 coincides satisfactorily with a very weak band at
757 cmꢀ1 29
The OH group vibrations are likely to be most sensi-
. The ring breathing mode at
H40
H80
H70
.
H60
tive to the environment so they show pronounced shifts in the
spectra of the hydrogen-bonded species. The absorption of non-
hydrogen bonded or free hydroxyl groups appears strongly in the
3550–3700 cmꢀ1 region. In general, the OH in-plane bending
vibration in phenol lies in the 1150–1270 cmꢀ1 region and is not
much affected due to hydrogen bonding. The FTIR frequency band
at 1143–1253 cmꢀ1 is attributed to this vibration. The OH out-of-
plane deformation vibration in phenol is located in the 517–
710 cmꢀ1 region for the associated OH.30 The FTIR frequency band
at 685 cmꢀ1 is correlated to this vibration. In both inter-molecular
and intra-molecular associations, the frequency is at a higher
H3
H30
value than in a free OH. The frequency increases with hydrogen
bond strength because of the larger amount of energy required to
twist the out-of-plane O–H bond.31
The aromatic structure of compound 1 shows the presence
of C–H stretching vibrations in the 2900–3200 cmꢀ1 region,
which is characteristic for the fast identification of the C–H
Table 4
Experimental and theoretical electronic absorption spectra values
Exp
Calculated/lcal (nm)
CIS
TD
ZNIDO
Wave length (nm)
Oscillator strength
Wave length (nm)
Oscillator strength
Wave length (nm)
Oscillator strength
489, 316, 226
428.86
325.13
197.62
0.0001
0.0015
0.2013
440.41
357.23
242
0.0001
0.0004
0.2909
387.89
342.76
317.73
1.0217
0.2862
0.0384

11780
A. Teimouri et al. / Tetrahedron 64 (2008) 11776–11782
2.4. UV–vis spectra
9.5
9
HF/6-31G(d)
B3LYP/6-311+G(2d,p)
R2 = 0.9941
The properties of azobenzenes, or in other words the –N]N–
group, have been mostly investigated by UV/vis spectroscopy and
various theoretical and experimental results have been reported.35
Absorption maxima (lmax) of compound 1 were calculated by the
CIS, ZNIDO, and TD methods. The observed and calculated visible
absorption maxima of 1 in this study are given in Table 4. Calcu-
lations of molecular orbital geometry show that the visible ab-
sorption maxima of this kind of azo dye correspond to the electron
transition from HOMO to LUMO. The lmax is a function of the
electron availability. This band was due to electronic transition of
R
2 = 0.9948
8.5
8
7.5
7
the naphthyl, phenyl ring, and azo group (transition of
p
–
p type).
*
Comparing the TD-B3LYP results, we have performed CIS cal-
culations on optimized structures, which lead to similar results. As
shown in Table 4, the energy and oscillator strength calculated by
CIS coincide reasonably with TD-DFT results as well as the experi-
mental values. However, ZNIDO correctly predicts much larger
oscillator strength.
6.5
6.5
7
7.5
Calculated 1H NMR chemical shifts (ppm)
8
8.5
9
9.5
Figure 7. Plot of the calculated versus the experimental 1H NMR chemical shifts (ppm)
of compound 1.
stretching vibrations. The vibrations in this region (2900–
3200 cmꢀ1) are in agreement with the experimental assignment
2.5. NMR spectra
of 3061–3098 cmꢀ1 32,33
The C–H in-plane bending vibrations
.
assigned in the 1050–1290 cmꢀ1 region are usually weak. The
absorption of C–H out-of-plane bending is predicted at
Experimental and theoretical values for 1H, 13C NMR, and the
calculated structural parameters of compound 1 are given in Tables
5 and 6 (in Supplementary data the 1H and 13C NMR spectra have
been provided). The theoretical 1H and 13C NMR chemical shifts of 1
have been compared with the experimental data. According to
these results, the calculated chemical shifts and coupling constants
are in line with the experimental findings. In order to compare the
experimental chemical shifts, correlation graphics based on the
calculations have been presented in Figures 7 and 8. The carbon and
proton chemical shifts’ correlation values are found to be 0.9913
1085 cmꢀ1 by the B3LYP/6-31G
, while HF calculations give
*
them at 1076 cmꢀ1
The calculations also show that the
pure, and contain significant contributions of other modes (
and (CN)). The stretching (C–N) vibrations could be observed for
the studied compound over a broad energy range, depending on
the -bonding nature of the C–N bond. The S–N stretching vibra-
tion exhibits a moderate band at 987 cmꢀ1. The band observed at
this region is not pure (SN) vibration, but contains a significant
contribution of (CH) mode. The bands corresponding to the N3
.
p(CH) vibrations are not
n(SN)
p
n
p
n
and 0.9919 for HF and B3LYP with the 6-31G basis set, respectively.
*
p
As shown in Figure 1, compound 1 has 26 different carbon
atoms, which is consistent with the structure based on molecular
symmetry. Chemical shifts were reported in parts per million
relative to TMS for 1H and 13C NMR spectra. Spectra were obtained
at a base frequency of 125.76 MHz for 13C and 500.13 MHz for 1H
nuclei. Relative chemical shifts were then estimated by using the
corresponding TMS shielding calculated in advance at the same
theoretical level as the reference. Calculated 1H and 13C isotropic
stretching vibrations belonging to the SO2N3 and azo group are
expected to appear near 2126 cmꢀ1 and 1507 cmꢀ1, respectively, in
the IR spectrum of this azo dye.
The observed bands at 1339 cmꢀ1 and 1143 cmꢀ1 were assigned
to the n(SO2) asym. and n(SO2) sym. modes, respectively. The band
at 504 cmꢀ1 was assigned to the SO2 scissors and SO2 wagging
vibrations, and has partly overlapped in this region. Calculations
show that
with the
stretching.
u(SO2) vibration contains a considerable contribution
chemical shielding for TMS at the HF/6-31G
*
and B3LYP/6-
p
ring.34 The major band (at 634 cmꢀ1) relates to the S–C
311þG(2d,p) levels in methanol were 32.60 ppm, 199.98 ppm, 31.88
ppm, and 182.46 ppm. The experimental values for 1H and 13C
isotropic chemical shifts for TMS were 30.84 ppm and 188.1 ppm,
respectively.36
The calculated NMR spectra of the other possible isomers of the
molecule are presented in Supplementary data section. Compari-
son between the calculated data for compound 1 and those
obtained reveals that the coupling has occurred at position 6 (see
Supplementary data).
165
160
155
150
145
140
135
130
125
120
115
110
HF/6-31G(d)
R2 = 0.9966
B3LYP/6-311+G(2d,p)
R2 = 0.9916
2.6. Thermodynamic properties
On the basis of vibrational analysis and statistical thermody-
namics, the standard thermodynamic functions: heat capacity
(Cop,m), entropy (Smo), and enthalpy (Hom) were obtained and listed
in Table 7. Several calculated thermodynamic parameters are pre-
sented in Table 8. Scale factors have been recommended37 for an
accurate prediction in determining the zero-point vibration ener-
gies and the entropy. The total energies and the change in the total
entropy at room temperature at different methods are also
presented.
105 110 115 120 125 130 135 140 145 150 155 160 165 170
Calculated 13C NMR chemical shifts (ppm)
Figure 8. Plot of the calculated versus the experimental 13C NMR chemical shifts
(ppm) of compound 1.

A. Teimouri et al. / Tetrahedron 64 (2008) 11776–11782
11781
Table 7
Thermodynamic properties at different temperatures at HF/6-31G
*
and B3LYP/6-31G level
*
T
Method
Etot (kcal/mol)
Htot (kcal/mol)
Stot (cal/mol K)
Cv (cal/mol K)
Gtot(kcal/mol)
298
HF
B3LYP
ꢀ1963.4926
ꢀ1973.6822
260.601
261.691
182.546
204.187
110.64
115.839
206.175
200.813
temperature of 0 ꢁC over a period of 60 min. A chilled aqueous so-
lution of sodium azide (20 g, 312 mmol, 200 ml) was added drop-
wise and the resultant solution allowed to stir for a further 60 min at
that temperature. The solution was then poured into an ice/water
slurry (1.5 L) and the white precipitate was collected by filtration,
washed with ice-cold water, and dried under vacuum. 4-Acet-
amidobenzenesulfonyl azide could be used in the next step directly
and recrystallized from a solution of acetone and water giving white
crystals (37.5 g, 75%); mp 108–110 ꢁC (Ref. 38, 113–114 ꢁC); dH
Table 8
Theoretically computed energies (a.u.), zero-point vibrational energies (kcal molꢀ1),
rotational constants (GHz), entropies (cal/mol K), and dipole moment (D) for com-
pound 1
Parameters
HF/6-31G
*
B3LYP/6-31G
*
Total energy
Zero-point energy
Rotational constant
ꢀ1963.4926
242.87998
0.25464
ꢀ1973.6822
242.43205
0.25464
0.03000
0.02888
0.03000
0.02888
(500 MHz, DMSO-d6): d 8.4 (s,1H, NH), 7.82 (d, 4H, J 8.3, phenyl), 2.23
Entropy
Total
Translational
Rotational
Vibrational
Dipole moment
(s, 3H, Me); dC (500 MHz, DMSO-d6): 169.5, 144.1, 132.3, 128.9, 119.6,
182.546
44.486
38.519
99.540
8.4250
204.187
44.486
38.519
121.182
9.7728
24.7; nmax (KBr): 2125, 1674, 1160 cmꢀ1; m/z: (EI-MS) 240 Mþ.
4.2.2. 4-Aminobenzenesulfonyl azide
4-Acetamidobenzenesulfonyl azide (12 g, 50 mmol) and con-
centrated HCl (12 M, 45 ml) were heated under reflux for 35 min,
then cooled to approximately 0–5 ꢁC. The solution was neutralized
with saturated sodium bicarbonate solution and solid sodium bi-
carbonate until a pH of approximately 6. The light brown mixture
was extracted with diethyl ether, washed, dried (MgSO4), and then
filtered. Evaporation of the diethyl ether solution provided a brown
solid, which could be recrystallized from a small portion of diethyl
ether (7.6 g, 70%); mp 34–36 ꢁC (Ref. 39, 35–39 ꢁC). [Found: C, 36.48;
H, 3.14; N, 28.32. C6H6N4O2S requires: C, 36.36; H, 3.05; N, 28.27%.]
dH (500 MHz, DMSO-d6): 7.7 (d, 2H, J 8 Hz, phenyl), 6.7 (d, 2H, J 8 Hz,
phenyl), 4.36 (br, 2H, –NH2); dC (500 MHz, DMSO-d6): 152.5, 129.8,
125.1, 116; nmax (KBr): 3475, 2128, 1175 cmꢀ1; m/z: (EIMS) 198 Mþ.
3. Conclusions
6-[4-(Azidosulfonyl)phenyl]-1-diazenyl-1,10-binaphthalen-2,20-
diol has beensynthesized and characterized byelemental analysis, IR,
UV–vis, 1H NMR, 13C NMR spectroscopy, and mass spectrometry. The
calculated vibrational frequencies and the experimental IR spectra
complement each other. The predicted electronic absorption spectra
have some blue shifts compared with the experimental data. Mo-
lecular orbital coefficient analysis suggests that the electronic spectra
are assigned to the
p/p electronic transitions. The experimental
*
and the theoretical investigations of this compound have been per-
formed successfully by using NMR and quantum chemical calcula-
tions. The computation analysis of this compound by HF and B3LYP
methods is in excellent agreement with all the experimental findings.
4.2.3. 6-[4-(Azidosulfonyl)phenyl]-1-diazenyl}-1,10-binaphthalen-
2,20-diol
4-Acetamidobenzenesulfonyl azide (2.4 g, 10 mmol) and con-
centrated HCl (12 M, 9 ml) were heated at reflux for 35 min, and the
resulting solution then cooled in an ice/salt bath to 0 ꢁC. The solution
was diazotized with a solution of sodium nitrite (0.76 g,10 mmol) in
water (20 ml), with the temperature maintained below 5 ꢁC, and
then stirred for a further 30 min. The solution was then neutralized
with saturated sodium bicarbonate solution. The reaction mixture
was stirred while maintaining a temperature of 0–5 ꢁC. To this
cooled mixture of p-diazonium benzene sulfonyl azide (2.4 g,
10 mmol),1,10-binaphthalene-2,20-diol (4.95 g,10 mmol) was added
slowly. After stirring for an additional 30 min by keeping tempera-
ture below 0 ꢁC, the mixture was further neutralized with a satu-
rated sodium carbonate solution (pH¼7) and then was maintained
stirring until precipitation was deemed to be complete (3–4 h). The
precipitate was filtered and recrystallized from toluene. The product
was obtained as red-orange crystals. Yield: 45%; mp 199–201 ꢁC.
[Found: C, 62.88; H, 3.38; N, 14.05; C26H17N5O4S requires: C, 63.02;
H, 3.46; N, 14.13%.] dH (500 MHz, DMSO-d6): 9.1 (br, 2H, –OH), 8.1
(1H, s, H5), 8 (1H, d, J 8.3 Hz, H7), 7.9 (1H, d, J 8.39 Hz, H8), 7.7 (4H, d,
4H, J 8.9 Hz, phenyl), 7.68 (1H, d, J 8.5 Hz, H50), 7.57 (2H, d, J 8.7 Hz,
H4, 40), 7.48 (1H, d, J 8.54 Hz, H80), 7.31 (1H, t, H70), 7.19 (1H, t, H60),
7.03 (2H, d, J 8.7 Hz, H3, 30); dC (500 MHz, DMSO-d6): 116.2 (C7),119.5
(C3, 30), 122.7 (C1, 10), 123.9 (C60), 124.6 (C12, 16), 125.8 (C80) 126.1
(C8), 127 (C70), 127.4 (C50), 128.5 (C13, 15), 128.9 (C4, 40), 130.2 (C9),
130.7(C100),131.7 (C5),133.4 (C90),133.5 (C10),143.7 (C14),149.9 (C6),
155.1(C2, 20), 159.2 (C11); nmax (KBr): 3311, 3306, 2126, 1582, 1570,
4. Experimental section
4.1. General
4-Acetamidobenzenesulfonyl chloride and (R)- or (S)-BINOL
were purchased from Merck and were used without further puri-
fication. Racemic BINOL was synthesized by the method reported
by Toda et al.19 IR spectra were recorded on a JASCO FT/IR-680 PLUS
spectrometer using KBr discs. NMR spectra recorded on a Bruker
500 ultrasheild spectrometer NMR and DMSO-d6 was used as sol-
vent. Mass spectra were determined on a Uk Fisons Trio 1000
spectrometer using electron impact at 70 ev. UV spectra were
recorded on a JASCO V-570 UV/Vis/NIR spectrophotometer. Ele-
mental analysis was determined using a LECO instrument. Specific
rotations were recorded on a JASCO 1030 polarimeter. Melting
points were obtained on a Gallenkamp apparatus and are not cor-
rected. Analytical TLC was performed on Silica Gel F254 plates
(Merck). Merck silica gel 60 (40–63
for column chromatography.
mm, 230–400 ASTM) was used
4.2. Typical procedure for diazotization and diazocoupling
reaction
4.2.1. 4-Acetamidobenzenesulfonyl azide
4-Acetamidobenzenesulfonyl chloride (48.6 g, 208 mmol) was
dissolved in acetone (500 ml) and the solution was cooled to
1507, 1379, 1339, 1192, 1168, 1143 cmꢀ1
; lmax (DCM) 226, 316,
489 nm; m/z: (EIMS) 495 Mþ.

11782
A. Teimouri et al. / Tetrahedron 64 (2008) 11776–11782
14. Dabbagh, H. A.; Teimouri, A.; Chermahini, A. N. Dyes Pigments 2007, 73,
Optically active azo dyes were synthesized under the optimized
reaction conditions, from optically active BINOL and specific rota-
tions are recorded in Table 1.
239.
15. Dabbagh, H. A.; Teimouri, A.; Chermahini, A. N.; Shiasi, R. Spectrochim. Acta. A
2006, 67, 437.
16. Dabbagh, H. A.; Teimouri, A.; Chermahini, A. N.; Shahraki, M. Spectrochim. Acta.
A 2008, 69, 449.
17. Chermahini, A. N.; Esfahani, M. N.; Dalirnasab, Z.; Dabbagh, H. A.; Teimouri, A.
J. Mol. Struct. (Theochem) 2007, 820, 7.
Acknowledgements
Support from the Payame Noor University in Isfahan research
council and help of Yasouj University are gratefully acknowledged.
Authors would like to thank Dr. M.S. Yalfani and Dr. M. Malakoti-
khah for critically reading the manuscript. In addition, we are
grateful to Dr. Z. Taboukht for her technical assistance.
18. Chermahini, A. N.; Dabbagh, H. A.; Teimouri, A. J. Mol. Struct. (Theochem) 2007,
822, 33.
19. Toda, F.; Tanaka, K.; Itawa, S. J. Org. Chem. 1989, 54, 3007.
20. Becke, A. D. J. Chem. Phys. 1993, 98, 5648.
21. Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B 1998, 37, 785.
22. Frisch, A.; Nielsen, A. B.; Holder, A. J. Gaussview Users Manual; Gaussian:
Pittsburg, 2003.
23. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.;
Cheeseman, J. R.; Montgomery, J. A., Jr.; Vreven, T.; Kudin, K. N.; Burant, J. C.;
Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.;
Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.;
Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.;
Kitao, O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.;
Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A.
J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth,
G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels,
A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.;
Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.;
Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.;
Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challa-
combe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.;
Pople, J. A. Gaussian 03, Revision C.02; Gaussian: Pittsburgh, PA, 2003.
24. Radom, L.; Pople, J. A. J. Am. Chem. Soc. 1970, 92, 4786.
25. Wolinski, K.; Hilton, J. F.; Pulay, P. J. Am. Chem. Soc. 1990, 112, 8251.
26. Raghavachari, K.; Trucks, G. W. J. Chem. Phys. 1989, 91, 1062.
27. Parkanyi, L.; Besenyei, G. J. Mol. Struct. 2004, 691, 97.
28. Scott, A. P.; Radom, L. J. Phys. Chem. 1996, 100, 16502.
29. Sing, N. D.; Yadav, R. A. Ind. J. Phys. 2001, 75, 347.
Supplementary data
Supplementary data associated with this article can be found in
the online version, at doi:10.1016/j.tet.2008.09.104.
References and notes
1. (a) Zollinger, H. Color chemistry, 3rd ed.; Helvetica Y. Chimica Acta: Switzerland,
2003; P 165; (b) Zollinger, H. Azo and Diazo Chemistry, Aliphatic and Aromatic
Compounds; Interscience: London, 1961; (c) Saunders, K. H.; Allen, R. L. M. Aro-
matic Diazo Compounds, 3rd ed.; Edward Arnold: London, 1985.
2. (a) Noyori, R. Asymmetric Catalysis in Organic Synthesis; Wiley: New York, NY,
1994; (b) Rosini, C.; Franzini, L.; Rafaelli, A.; Salvadori, P. Synthesis 1992, 503; (c)
Pu, L. Chem. Rev. 1998, 98, 2405; (d) Shibasaki, M.; Sasai, H.; Arai, T. Angew.
Chem., Int. Ed. 1997, 36, 1236; (e) Tayama, H.; Tanaka, H. Tetrahedron Lett. 2007,
48, 4183; (f) Ha, W.; Shan, Z. Tetrahedron: Asymmetry 2006, 17, 854.
3. (a) Vogl, M. E.; Matsunaga, S.; Kanai, M.; Iida, T.; Shibasaki, M. Tetrahedron Lett.
1998, 39, 7917; (b) Nakajima, M.; Sasaki, Y.; Shiro, M.; Hashimoto, M. Tetrahe-
dron: Asymmetry 1997, 8, 341; (c) Dabbagh, H. A.; Chermahini, A. N.; Bani-
bairami, S. Tetrahedron Lett. 2006, 47, 3929; (d) Lu, Y. N.; Guo, O. S.; Jiang, F. Y.;
Li, J. S. Tetrahedron: Asymmetry 2006, 17, 1842.
30. Varasanyi, G. Assignments for Vibrational Spectra of Seven Hundred Benzene
Derivatives; Adam Hilger: London, 1974; Vols. 1–2.
31. Nuquist, R. A. Spectrochim. Acta 1963, 19, 1655.
32. Rastogi, K.; Palafox, M. A.; Tanwar, R. P.; Mittal, L. Spectrochim. Acta 2002, 58,
1987.
4. (a) Gong, Y. O.; Zhoua, Y. F.; Hana, L.; Wanga, R. H.; Wua, B. L.; Loua, B. Y.; Hong,
M. C. J. Mol. Struct. 2005, 748, 195; (b) Fan, Q. H.; Liu, G. H.; Deng, G. J.; Chen, X.
M.; Chan, A. S. C. Tetrahedron Lett. 2001, 42, 9047.
33. Silverstein, M.; Clayton, G.; Morill, C. Spectrometric Identification of Organic
Compounds; Wiley: New York, NY, 1981.
5. (a) Kii, S.; Maruoka, K. Tetrahedron Lett. 2001, 42, 1935; (b) Brunel, J. M. Chem.
Rev. 2005, 105, 857; (c) Pellissier, H. Tetrahedron 2006, 62, 2143.
34. Roegers, P. G. A Guide to the Complete Interpretation of Infrared Spectra of Organic
Structures; Wiley: Chichester, UK, 1994.
6. (a) Periasamy, M.; Venkatraman, L.; Sivakumar, S.; Sampathkumar, N.; Ram-
anathan, C. R. J. Org. Chem. 1999, 64, 7643; (b) Hu, Q. S.; Vitharana, D. R.; Pu, L.
Tetrahedron: Asymmetry 1995, 6, 2123.
7. Yoichi, M. A.; Ichinohe, Y. M.; Takahashi, H.; Ikegami, S. Tetrahedron Lett. 2002,43, 3431.
8. (a) Harada, T.; Matsui, S. I.; Tuyet, T. M. T.; Hatsuda, M.; Ueda, S.; Oku, A.; Shiro,
M. Tetrahedron: Asymmetry 2003, 14, 3879; (b) Anderson, S.; Neidlein, U.;
Gramlich, V.; Diedrerich, F. Angew. Chem., Int. Ed. Engl. 1995, 34, 1596.
9. Clark, J. H.; Macquarrie, D. J. Chem. Soc. Rev. 1996, 25, 303.
35. (a) Chiang, W. Y.; Laane, J. J. Chem. Phys. 1994, 100, 8755; (b) Molina, V.;
Merchan, M.; Roos, B. O. J. Phys. Chem. A 1997, 101, 3478; (c) Kwasniewski,
S. P.; Deleuze, M. S.; Francois, J. P. Int. J. Quantum Chem. 2000, 80, 672; (d)
Kwasniewski, S. P.; Francois, J. P.; Deleuze, M. S. Int. J. Quant. Chem. 2001, 85,
557.
36. Cheeseman, J. R.; Trucks, G. W.; Keith, T. A.; Frisch, M. J. J. Chem. Phys. 1996, 104,
5497.
37. Palafox, M. A. Int. J. Quant. Chem. 2000, 77, 661.
10. Reetz, M. T.; Merk, C.; Mehler, G. Chem. Commun. 1998, 2075.
11. Sudo, Y.; Yamaguchi, V.; Shinbo, V. J. Chromatogr., A 1998, 35, 813.
12. Sahnoun, R.; Koseki, S.; Fujimura, Y. J. Mol. Struct. 2005, 316, 735.
13. Meca, L.; Ryeha, D.; Havlas, Z. J. Org. Chem. 2003, 68, 5677.
38. Griffiths, J.; Mcdarmaid, R. I. J.S.D.C. 1977, 93, 455.
39. Chang, K.; Lin S.; Tzeng, W.; Hong, S. U.S. Patent 6,313,314, 2001.