Novel arylated chloro- and methoxy-1,3-dibutadienes: Influence of substituents on molecular conformation and crystal packing

Article abstract of DOI:10.1016/j.molstruc.2014.04.028

Three novel arylated chloro- and methoxy-1,3-butadienes were prepared and studied by a combination of spectroscopic (UV/vis, IR and NMR) and X-ray crystallographic methods. Influence of substituent on the molecular conformation and crystal packing (i.e. intermolecular interactions) was studied. It was predicted that the differences in electronic and steric effects of two chlorine atoms in comparison to two methoxy groups as substituents at different locations in the molecule would provide various packing of the molecules and cause different assumptions for the photochemical behaviour.

Full text of DOI:10.1016/j.molstruc.2014.04.028

Journal of Molecular Structure 1068 (2014) 124–129
Contents lists available at ScienceDirect
Journal of Molecular Structure
journal homepage: www.elsevier.com/locate/molstruc
Novel arylated chloro- and methoxy-1,3-dibutadienes: Influence
of substituents on molecular conformation and crystal packing
a
b,
a
⇑
ˇ
´
Dragana Vuk , Krešimir Molcanov , Irena Škoric
a Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Maruli´cev Trg 19, 10000 Zagreb, Croatia
b
ˇ
Department for Physical Chemistry, Rudjer Boškovi´c Institute, Bijenicka 54, 10000 Zagreb, Croatia
h i g h l i g h t s
ꢀ
ꢀ
ꢀ
Three novel arylated 1,3-butadienes were prepared.
Isomers in solution were studied by NMR and UV/Vis spectroscopy.
Influence of the substituents (and different positions of substituents) on the molecular conformation.
a r t i c l e i n f o
a b s t r a c t
Article history:
Three novel arylated chloro- and methoxy-1,3-butadienes were prepared and studied by a combination
of spectroscopic (UV/vis, IR and NMR) and X-ray crystallographic methods. Influence of substituent on
the molecular conformation and crystal packing (i.e. intermolecular interactions) was studied. It was pre-
dicted that the differences in electronic and steric effects of two chlorine atoms in comparison to two
methoxy groups as substituents at different locations in the molecule would provide various packing
of the molecules and cause different assumptions for the photochemical behaviour.
Ó 2014 Elsevier B.V. All rights reserved.
Received 13 February 2014
Received in revised form 8 April 2014
Accepted 8 April 2014
Available online 19 April 2014
Keywords:
1,3-Butadienes
Weak interactions
Crystal structure
Crystal engineering
NMR spectroscopy
Photochemistry
Introduction
affect on dibutadiene unit by mesomeric and inductive effect.
Understanding the key effects of chlorine substituent in photo-
Synthetic organic photochemistry occasionally provides an easy
access to complicated structures, difficult to obtain by a classical
synthetic approach [1]. Among the most studied and used reac-
tions are the intra- and intermolecular photocycloadditions [2].
Important precursors for these reactions are butadiene derivatives
of o-divinylbenzenes. Under their prolonged conjugated system,
these compounds could participate in photochemical reactions
and give novel complex structures [3,4].
In order to study the influence of chlorine as a substituent on
the photochemical behaviour of conjugated butadiene systems
[5–7], dichloro derivatives of butadiene 1–2 were synthesized.
The initial compounds 1–2 undergo photochemical reaction to give
new polycyclic structures [4]. Their formation depends on the
electronic and steric effects of two chlorine atoms, bounded as
substituent on different locations in the molecule. Chlorine can
chemical reaction of these butadiene derivatives, makes the syn-
thesis of these systems suitable for routing photoreaction
towards various interesting structures for further transformations
and functionalization.
In continuation of our interest in effect of substituent on intra-
molecular photocycloaddition reactions, we extended synthesis to
para-metoxy substitued 1,3-butadiene derivative 3. It could be
expected that very similar compounds with different substitution
may display diverse photoreactivity and consequently new type
of products, interesting for further studies.
Results and discussion
Synthesis and spectroscopic characterization
Butadiene derivatives 1–3 were prepared by Wittig reaction from
diphosphonium salt and the corresponding cinnamaldehydes
(Scheme 1). The products were obtained in good yields (50–70%)
⇑
Corresponding author. Tel.: +385 1 4561025.
ˇ
E-mail address: kmolcano@irb.hr (K. Molcanov).
http://dx.doi.org/10.1016/j.molstruc.2014.04.028
0022-2860/Ó 2014 Elsevier B.V. All rights reserved.

D. Vuk et al. / Journal of Molecular Structure 1068 (2014) 124–129
125
as mixture of three isomers (cis,cis-, cis,trans- and trans,trans-),
1,0
0,5
0,0
(a)
which were separated by column chromatography and completely
characterised spectroscopically. Because the synthesis were per-
formed always from the corresponding (E) geometric isomers of
the cinnamaldehyde, the second double bond (looking from the
ortho-substitued central benzene ring) in the products retain the
(E) configuration. Hence, the number of the geometric isomers was
reduced.
Fig. 1a shows the absorbtion spectra of starting trans,trans-iso-
mers 1–2 in ethanol. Band absorption maxima of these com-
pounds are found in the range of 350–375 nm. Trans,trans-
isomer of 2, which has the same configuration but different loca-
tion of chlorine atoms substitution, show a bathochromic shift in
comparison to trans,trans-isomer of 1. This effect can be explained
trans,trans-1
trans,trans-2
trans,trans-3
A
250
300
350
400
450
λ/ nm
by better delocalization of
p-electrons in the absence of the chlo-
rine on the butadiene units.
The UV spectra of separated cis,cis-, cis,trans- and trans,trans-
isomers of metoxy derivative 3 clearly show the configuration
influence on absorption characteristic (Fig. 1b). Maxima wave-
lengths of these isomers are in the range of 300–400 nm. The
trans,trans-isomer show a bathochromic shift and an increase of
the molar absorption coefficient in comparison to their cis,trans-
and cis,cis-isomers, as expected. The reason for this effect is
increased molecular planarity of trans,trans configuration and the
150000
125000
100000
75000
50000
25000
0
(b)
cis,cis-3
cis,trans-3
trans,trans-3
possibility of better delocalisation of
p electrons.
The 1H NMR spectra of the compounds 1–2 are presented in Fig. 2.
The signals of ethenylicprotons (exept HB protons of trans,trans-2) of
both derivatives are widespread between 6.60–7.10 ppm, and have
very similar chemical shift. Therefore, the effect of position of chlo-
rine atoms is in this case negligible. The exception is HB ethenylic
proton of trans,trans-isomer of 2, which is drastically shifted to
7.44 ppm. The reason for this phenomenon is strong electronic effect
of chlorine atoms on butadiene units to nearby protons.
200
250
300
350
400
450
λ /nm
Fig. 1. UV spectra in ethanol: (a) trans,trans izomers of compounds 1–3; (b) cis,cis-,
cis,trans- and trans,trans-isomers of compound 3.
Fig. 3 shows the 1H NMR spectra of cis,cis-, cis,trans- and trans,-
trans-isomers of metoxy derivative 3 with the emphasis on ethyl-
enic protons. These protons in all examples appear as doublet or
doublet of doublets between 6.42 and 7.00 ppm. Under increased
molecular planarity of trans,trans-isomer, the trans-ethylenic pro-
tons as expected are shifted to higher field, in comparison to the
signals of cis-protons.
the central phenyl ring (i.e. bonds C11AC11i and C13AC13i, i = x,
y, 1 À z). The molecule is relatively flat (Fig. 6a), with angle
between terminal phenyl groups (C1 ? C6) of 28.8°. Molecule of
trans,trans-1 is twisted and chiral (Figs. 4b and 5b), its molecular
symmetry being C1. One of its chlorine atoms is disordered over
two positions (designated as Cl2 and Cl2a) with respective popula-
tions of 0.63 and 0.37.
Crystal structures
The entire molecule of each compound comprises a conjugated
system, so both can be regarded as single, delocalised,
systems. The formally single CAC bonds in the butadienyl fragment
(bonds C4AC7, C8AC9 and C10AC11; in trans,trans-1 there are also
p electron
Conformations of molecules of trans,trans-1 and trans,trans-2
are very different. Symmetry of trans,trans-2 is Cs (Fig. 4a), with
the crystallographic mirror plane passing through the middle of
-
-
+
+
2
2
3
3
a
3
Scheme 1. Synthesis of butadiene derivatives 1–3 by Wittig reaction.

126
D. Vuk et al. / Journal of Molecular Structure 1068 (2014) 124–129
HD
HA Cl
HA
H
B
HB HD
Cl
Cl
HA HC
HD
HB
HA /HD
HA /HD
HB /HC
HB /HC
Cl
7.6
Fig. 2. 1H NMR spectra of the trans,trans isomers of compounds 1–2 (CDCl3, 600 MHZ).
PPM
7.4
7.2
7.0
6.8
HB
HA
HD
HC
HD
HB
HA
H3CO
OCH3
HC
OCH3
HA',H B',H C
'
HB
HC
'
HA
HD
HA
'
H ,H '
HD
'
D HA
HB
D
HC
HB
'
HC
H3CO
OCH3
HA HC
HB/HC
HA/HD
HB HD
HA/HD
HB/HC
OCH3
PPM
7.4
7.2
7.0
6.8
6.6
6.4
Fig. 3. 1H NMR spectra of cis,cis-, cis,trans- and trans,trans-isomers of compound 3 CDCl3, 600 MHZ).
Fig. 5. Side-view showing conformations of molecules of trans,trans-2 (above) and
trans,trans-1 (below).
fragments C16AC17, C18AC19 and C20AC21) are significantly
shortened (Table 1), indicating
delocalisation.
a
considerable electron
Crystal packing of trans,trans-2 is dominated by hydrogen
bonded layers parallel to the plane (101), which are generated
Fig. 4. Molecular structures of compounds trans,trans-1 and trans,trans-2. Dis-
placement ellipsoids are drawn for the probability of 50% and hydrogen atoms are
shown as spheres of arbitrary radii.
by
a
single symmetry-independent CAHÁ Á ÁCl hydrogen bond
(Fig. 6a, and Table 2). The molecules are stacked in the direction

D. Vuk et al. / Journal of Molecular Structure 1068 (2014) 124–129
127
Table 1
Selected bond lengths (Å). There are two symmetry-independent butadienyl
fragments in trans,trans-1, so they are listed separately.
trans,trans-2
trans,trans-1
trans,trans-1
C4AC7
C7AC8
C8AC9
C9AC10
C10AC11
1.464(9)
1.317(8)
1.462(9)
1.311(8)
1.469(7)
1.469(4)
1.338(4)
1.459(4)
1.341(5)
1.478(5)
C21AC20
C20AC19
C19AC18
C18AC17
C17AC16
1.474(4)
1.311(5)
1.476(5)
1.322(4)
1.479(4)
Fig. 7. Crystal packing of trans,trans-1: (a) double chains generated by a pair of
CAHÁ Á ÁCl hydrogen bonds extending in the direction [010], (b) hydrogen bonded
chains parallel to [001]. Symmetry operators: (i) x, y, À1 + z; (ii) 2 À x, À1/2 + y,
1 À z; (iii) x, À1 + y, À1 + z.
metry-independent bonds: C18AH18Á Á ÁCl2b and C20AH20Á Á ÁCl2a
(Table 2). Another hydrogen bond, C1AH1Á Á ÁCl2b links the mole-
cules into chains parallel to [001] (Fig. 7b, and Table 2); 2D motive
parallel to (100) is thus formed. 3D packing is achieved through
Fig. 6. Crystal packing of trans,trans-2: (a) layers generated by CAHÁ Á ÁCl hydrogen
bonding, and (b) stacking of molecules which generates 3D packing.
several CAHÁ Á Á
p interactions (Table 4).
[010] through interactions between their aromatic moieties
(Fig. 6b, and Table 3). Therefore, stacking of layers produces a 3D
structure.
Crystal packing of trans,trans-1 is more complicated. CAHÁ Á ÁCl
hydrogen bonds generate double chains running in the direction
[010] (Fig 7a); due to the disorder of Cl2 atom, there are two sym-
Conclusions
As it was shown, the photochemical behaviour of dichloro-
substituted butadiene derivatives was studied and it was con-
firmed [4] that these compounds display diverse photochemical
behaviour. The
a-chloro derivative 1 photocyclizes to give six-
Table 2
Geometric parameters of hydrogen bonds.
D–H (Å)
HÁ Á ÁA (Å)
DÁ Á ÁA (Å)
D–HÁ Á ÁA (°)
Symm. op. on A
trans,trans-1
C1AH1Á Á ÁCl2b
0.93
0.93
3.04
2.82
3.593(5)
3.592(6)
120
141
x, –1 + y, –1 + z
2 À x, –1/2 + y, 1 À z
C18AH18Á Á ÁCl2b
trans,trans-2
C6AH6Á Á ÁCl1
0.93
0.93
3.05
2.89
3.826(8)
3.617(5)
142
136
–1/2 + x, 1 À y, 1/2 À z
x, y, –1 + z
C20AH20Á Á ÁCl2a
Table 3
Geometric parameters of the
pÁ Á Áp
interactions in trans,trans-2.
CgaÁ Á ÁCg (Å)
pÁ Á Á
p
ab
bc
CgÁ Á Áplane(Cg2) (Å)
Offset (Å)
Symm. op.
C1 ? C6Á Á ÁC1 ? C6
4.012(4)
4.012(4)
0.00
0.00
22.35
22.35
3.711(2)
3.711(2)
1.526
1.526
x, –1 + y, 1 À z
x, –1 + y, 1 À z
C11 ? C11dÁ Á ÁC11 ? 11d
a
b
c
Cg = centre of gravity of the aromatic ring.
= angle between planes of two aromatic rings.
a
b = angle between CgÁ Á ÁCg line and normal to the plane of the first aromatic ring.
d
Symmetry operator x, y, 1 À z.

128
D. Vuk et al. / Journal of Molecular Structure 1068 (2014) 124–129
Table 4
Synthesis
To
Geometric parameters of the CAHÁ Á Á
p interactions in trans,trans-1.
HÁ Á ÁCg
c
(°)a
CAHÁ Á ÁCg
(°)
CÁ Á ÁCg
Symm.
operation
on Cg
a
stirred solution of the triphenylphosphonium salt
(Å)
(Å)
(0.005 mol) and the corresponding aldehyde (0.011 mol) in abso-
lute ethanol (100 mL) the solution of sodium ethoxide (0.253 g,
0.011 mol in 15 mL of absolute ethanol) was added dropwise.
The reaction was completed within 3–4 h (usually was left to stand
overnight). After removal of the solvent, the residue was worked
up with water and toluene. The toluene extracts were dried (anhy-
drous MgSO4) and concentrated. The crude reaction mixture was
purified and the isomers of products 1 (55%), 2 (50%) and 3 (70%)
were separated by repeated column chromatography on silica gel
using petroleum ether/dichloromethane (9:1) as the eluent. The
first fractions yielded cis,cis-, cis,trans- and the last fractions trans,-
trans-isomer. The (1Z,3E)-4-{o-[(1E,3Z)-3-Chloro-4-phenyl-1,3-
C6AH6Á Á ÁC21 ? C26
C22–H22Á Á ÁC21 ? C26
2.85
2.84
14.82 128
5.58 128
3.495(4) x, y, –1 + z
3.489(3) 1 À x, –
½ + y,
1 À z
C24AH24Á Á ÁC11 ? C16 2.91
13.18 150
3.741(4) 1 À x,
½ + y,
1 À z
C3AH3Á Á ÁC4AC7b
2.84
–
143
3.631(5) 2 À x, –1/
2 + y, –z
a
c
= angle defined by a line connecting centre of gravity of the aromatic ring with
H atom and the normal to the aromatic ring.
b
The CAH group is directed towards a C@C bond. Therefore, Cg refers to the
midpoint of the C4AC7 bond.
butadienyl]phenyl}-2-chloro-1-phenyl-1,3-butadiene
(1)
and
(1E,3E)-1-{o-[(1E,3E)-4-(p-Chlorophenyl)-1,3-butadienyl]phenyl}-
4-(p-chlorophenyl)-1,3-butadiene (2) are described [4]. The data of
the new compound 3 are given below.
membered ring photoproduct. p-Chloro-substituted butadiene 2
undergoes intramolecular [2 + 2] cycloaddition followed by forma-
tion of benzobicyclic structures. It was proposed that the steric
hindrance of chlorines in a-positions in the combination with spe-
cific weak interactions causes a greater deviation from planarity,
relative to p-substitution, shifts conformer equilibria and affects
the reaction pathways and yields. Those results are in accordance
with this study by the presented X-ray crystallographic methods.
Replacing the p-chloro substituents by p-methoxy functional
groups probably changes the electronic influence and crystal pack-
ing and can show different sequence to the photochemical
reaction.
Since no strong proton donors are present, the molecules are
held together by weak intermolecular interactions: CAHÁ Á ÁO and
CAHÁ Á ÁCl hydrogen bonds, CAHÁ Á Á
p interactions and dispersion
interactions. Therefore, crystal packing of compounds trans,trans-
1 and trans,trans-2 depends on a subtle interplay of weak interac-
tion and steric effects.
Experimental section
(1Z,3E)-1-{o-[(1Z,3E)-4-(p-Methoxyphenyl)-1,3-butadienyl]phenyl}-
4-(p-methoxyphenyl)-1,3-butadiene (cis,cis-5)
Physical measurements
18%; Rf 0.61 (petroleum ether/dichloromethane = 6:4); colour-
less oil; UV (96% EtOH) kmax 339 (4.63), 311 (4.66); 1H NMR (CDCl3,
600 MHz) d 7.42 (d, J = 9.0 Hz, 1H), 7.31 (d, J = 9.0 Hz, 1H), 7.29 (d,
J = 8.7 Hz, 2H), 7.00 (dd, J = 15.5; 10.9 Hz, 1H), 6.76 (d, J = 8.7 Hz,
2H), 6.62 (d, J = 15.5 Hz, 1H), 6.47 (d, J = 11.2 Hz, 1H), 6.42 (t, 1H,
J = 11.2 Hz), 3.76 (s, 3H, AOCH3); 13C NMR (CDCl3, 75 MHz) d
158.8 (s), 136.2 (s), 133.6 (d), 130.6 (d), 129.7 (s), 129.5 (d),
128.1 (d), 127.4 (2d), 126.3 (d), 123.3 (d), 113.6 (2d), 56.4 (q); IR
mmax. 3022, 1509, 1336, 979, 768.
The 1H spectra were recorded on a spectrometer at 600 MHz.
The 13C NMR spectra were registered at 150 MHz, respectively.
All NMR spectra were measured in CDCl3 using tetramethylsilane
as reference. The assignment of the signals is based on 2D-CH cor-
relation and 2D-HH-COSY experiments. UV spectra were measured
on a UV/VIS Cary 50 spectrophotometer. IR spectra were recorded
on a FTIR-ATR (film) with resolution of 4 cmÀ1. Irradiation experi-
ments were preformed in a quartz vessel in toluene solution in a
photochemical reactor equipped with 3000 Å lamps. All irradiation
experiments were carried out in deaerated solutions by bubbling a
stream of argon prior to irradiation. Melting points were obtained
using microscope equipped apparatus and are uncorrected. HRMS
analysis were carried out on a mass spectrometer (MALDI TOF/
TOF analyzer), equipped with Nd:YAG laser operating at 355 nm
with firing rate 200 Hz in the positive (H+) or negative (HÀ) ion
reflector mode. Silica gel (0.063–0.2 mm) was used for chromato-
graphic purifications. Thin-layer chromatography (TLC) was per-
formed silica gel 60 F254 plates. Solvents were purified by
distillation.
(1Z,3E)-1-{o-[(1E,3E)-4-(p-Methoxyphenyl)-1,3-butadienyl]phenyl}-
4-(p-methoxyphenyl) -1,3-butadiene (cis,trans-5)
47%; Rf 0.61 (petroleum ether/dichloromethane = 6:4); colour-
less oil; UV (96% EtOH) kmax 353 (4.90), 327 (4.85); 1H NMR (CDCl3,
600 MHz) d 7.53 (d, J = 7.7 Hz, 1H), 7.28 (d, J = 8.7 Hz, 2H), 7.25 (d,
J = 7.7 Hz, 1H), 7.21 (d, J = 8.7 Hz, 2H), 7.19 (t, J = 7.7 Hz, 1H), 7.16
(t, J = 7.7 Hz, 1H), 6.87 (dd, J = 15.6; 11.1 Hz, 1H), 6.78 (d,
J = 8.7 Hz, 2H), 6.73 (d, J = 8.7 Hz, 2H), 6.72–6.82 (m, 3H), 6.58 (d,
J = 15.6 Hz, 1H), 6.54 (d, J = 15.6 Hz, 1H), 6.52 (d, J = 11.1 Hz, 1H),
6.42 (t, J = 11.1 Hz, 1H), 3.74 (s, 3H, AOCH3), 3.70 (s, 3H, AOCH3);
13C NMR (CDCl3, 75 MHz) d 158.9 (s), 158.8 (s), 135.7 (s), 135.4
(s), 133.6 (d), 132.1 (d), 130.9 (d), 130.6 (d), 130.0 (d), 129.8 (s),
129.7 (s), 129.2 (d), 127.8 (d), 127.3 (2d), 127.1 (2d), 126.8 (d),
126.4 (d), 124.9 (d), 123.1 (d), 113.7 (2d), 113.6 (2d), 54.80 (q),
54.77 (q); IR mmax. 3027, 1602 (C@C, ar), 1509 (C@C), 1250 (Car-
AOACH3), 1174, 1032, 751.
Para-metoxi-cinnamaldehyde,
para-chloro-cinnamaldehyde
and alpha-chloro-cinnamaldehyde were obtained from a commer-
cial source, b,b-o-xylyl(ditriphenylphosphonium) dibromide was
prepared from o-xylyldibromide and triphenylphosphine in
dimethylformamide.

D. Vuk et al. / Journal of Molecular Structure 1068 (2014) 124–129
129
Table 5
Crystallographic, data collection and structure refinement details.
Crystallography
Single crystal measurements were performed on an Oxford Dif-
fraction Xcalibur Nova R (microfocus Cu tube) at room temperature
[293(2) K]. Only the symmetry-independent part of the Ewald
sphere was measured; no Friedel pairs were measured in the case
of non-centrosymmetric crystals. Program package CrysAlis PRO
[8] was used for data reduction. The structures were solved using
SHELXS97 [9] and refined with SHELXL97 [9]. The models were
refined using the full-matrix least squares refinement; all non-
hydrogen atoms were refined anisotropically. Hydrogen atoms
were modelled as riding entities using the AFIX command.
Compound
trans,trans-1
26H20Cl2
trans,trans-2
Empirical formula
C
C26H20Cl2
403.32
Formula wt./g molÀ1
403.32
Crystal dimensions/mm
Space group
a/Å
b/Å
c/Å
0.18 Â 0.14 Â 0.08
0.10 Â 0.06 Â 0.04
P 21 n m
6.8871(4)
4.0120(3)
36.501(3)
90
90
90
2
1008.57(12)
1.328
2.941
4.85–75.40
293(2)
P 21
12.9820(3)
5.8510(1)
15.2038(4)
90
113.870(3)
90
a
/°
b/°
/°
c
Z
2
Molecular geometry calculations were performed by PLATON
[10], and molecular graphics were prepared using ORTEP-3 [11],
and CCDC-Mercury [12]. Crystallographic and refinement data for
the structures reported in this paper are shown in Table 5.
V/Å3
1056.07(4)
1.268
2.809
3.18–75.80
293(2)
Dcalc/g cmÀ3
l
/mmÀ1
H
range/°
T/K
Radiation wavelength
Diffractometer type
Range of h, k, l
1.54179 (Cu K
Xcalibur Nova
–16 < h < 15;
–7 < k < 5;
–19 < l < 18
5060
3224
3116
Multi-scan
0.0180
0.0447
0.1316
0.880
Constrained
164
1
a)
1.54179 (Cu K
Xcalibur Nova
–8 < h < 8;
–3 < k < 5;
–45 < l < 34
2738
1618
1478
Multi-scan
0.0622
0.0760
0.2309
1.111
Constrained
127
1
a)
Appendix A. Supplementary material
Supplementary crystallographic data for this paper can be
obtained free of charge via www.ccdc.cam.ac.uk/conts/retriev-
ing.html (or from the Cambridge Crystallographic Data Centre,
12, Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033;
or deposit@ccdc.cam.ac.uk). CCDC 986521 and 986522 contain
the supplementary crystallographic data for this paper. Supple-
mentary data associated with this article can be found, in the
online version, at http://dx.doi.org/10.1016/j.molstruc.2014.
04.028.
Reflections collected
Independent reflections
Observed reflections (I P 2
Absorption correction
Rint
r
)
R (F)
Rw (F2)
Goodness of fit
H atom treatment
No. of parameters
No. of restraints
D
qmax
,
D
qmin (eÅ–3
)
0.189; À0.285
0.450; À0.313
References
(1E,3E)-1-{o-[(1E,3E)-4-(p-Methoxyphenyl)-1,3-butadienyl]phenyl}-
4-(p-methoxyphenyl)-1,3-butadiene (trans,trans-5)
5%; Rf 0.61 (petroleum ether/dichloromethane = 6:4); yellow
crystals; mp 212–214 °C; UV (96% EtOH) kmax (log e) 363 (5.08),
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325 (5.16); 1H NMR (CDCl3, 600 MHz) d 7.51 (d, J = 9.1 Hz, 1H),
7.40 (d, J = 8.6 Hz, 2H), 7.21 (d, J = 9.1 Hz, 1H), 6.97 (d, J = 15.1 Hz,
1H), 6.90 (dd, J = 15.1; 10.5 Hz, 1H), 6.88 (d, J = 8.6 Hz, 2H), 6.83
(dd, J = 15.1; 10.5 Hz, 1H), 6.64 (d, J = 15.1 Hz, 1H), 3.83 (s, AOCH3);
13C NMR (CDCl3, 75 MHz) d 158.9 (s), 135.2 (s), 132.1 (d), 131.2 (d),
129.7 (s), 128.7 (d), 127.2 (2d), 127.1 (d), 126.9 (d), 125.7 (d), 113.7
(2d), 54.8 (q); IR mmax. 2918, 1597 (C@C, ar), 1510 (C@C), 1252
(CarAOACH3), 1172, 1029, 993, 752; HRMS (TOF ES+) m/z for
ˇ
ˇ
´
´
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I. Škoric, J. Mol. Struct. 1051 (2013) 1.
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3758.
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Towler, J. ven de Streek, J. Appl. Cryst. 39 (2006) 453–457.
C
28H26O2: M+calcd 394.1927; Mf+ound 394.1937 (for a mixture of
isomers 3).