Tetraallyl ethers of thiacalix[4]arenes in the 1,3-alternate conformation

Article abstract of DOI:10.1007/s10870-010-9883-7

The O-alkylation of thiacalix[4]arene and of two derivatives substituted in p-position by NO₂ and p-N=N-C₆H₄-NO ₂ with allylbromide leads to tetraallyl ethers in the 1,3-alternate conformation (1-3) as proved by

Full text of DOI:10.1007/s10870-010-9883-7

J Chem Crystallogr (2011) 41:332–337
DOI 10.1007/s10870-010-9883-7
ORIGINAL PAPER
Tetraallyl Ethers of Thiacalix[4]arenes in the 1,3-Alternate
Conformation
•
Oleg Kasyan Valentyn Rudzevich
•
•
Michael Bolte Volker Bohmer
¨
Received: 24 February 2010 / Accepted: 25 August 2010 / Published online: 7 September 2010
Ó Springer Science+Business Media, LLC 2010
Abstract The O-alkylation of thiacalix[4]arene and of two
derivatives substituted in p-position by NO2 and p-N=N–
C6H4–NO2 with allylbromide leads to tetraallyl ethers in the
1,3-alternate conformation (1–3) as proved by X-ray crys-
tallography. Compound 1 crystallized in the trigonal space
tubes parallel to the a-axis. Layers of molecules parallel to
the a, b-plane are found for compound 2.
Keywords Thiacalix[4]arenes Á 1,3-Alternate Á Allyl
ethers Á X-ray analysis
˚
group P3221 with unit cell parameters a = 10.9608(4) A,
˚
˚
b = 10.9608(4) A, c = 24.6730(12) A; a = 90°, b = 90°,
c = 120° and Z = 3. Compound 2 crystallized in the
orthorhombic space group Pbca with unit cell parameters
Introduction
˚
˚
˚
Calix[4]arenes fixed in the cone-conformation by suffi-
ciently sized ether residues (propyl or larger) and substi-
tuted in p-position by amino groups (e.g. [1]) are suitable
educts for the introduction of various further functional
groups, which may be attached e.g. via amide links. Tetra-
CMPO (CMPO = carbamoylmethylphosphine oxide used
here for the diphenyl substituted residue exclusively)
derivatives [2], as an example, are excellent extractants for
actinides or lanthanides. Tetra-picolylamides have been
proposed for similar purposes [3]. Tetra-urea derivatives,
on the other hand, are interesting due to their ability to
form dimeric capsules [4, 5], which may be used also to
construct larger self-assembled structures [6–8]. Thiaca-
lix[4]arenes, in which phenolic units are connected via
sulfur bridges, are somewhat larger and slightly different in
shape [9]. This difference might be useful to change or to
fine-tune selectivities for certain derivatives in comparison
to their calix[4]arene analogues.
a = 12.8608(4) A, b = 17.5209(5) A, c = 33.6527(9) A;
a = 90°, b = 90°, c = 90° and Z = 8. Compound 3 crys-
tallized in the monoclinic space group P21/n with unit
˚
cell parameters a = 18.7825(19) A, b = 17.6662(13) A,
˚
˚
c = 19.7828(18) A; a = 90°, b = 114.152(7)°, c = 90°
and Z = 4. Subtle differences in the molecular shape of the
calix[4]arene core were found. The unsubstituted compound
1 forms three alternating layers with parallel tubes of dif-
ferent orientation, while for 3 all molecules are arranged in
¨
O. Kasyan Á V. Rudzevich Á V. Bohmer (&)
Abteilung Lehramt Chemie, Fachbereich Chemie,
Pharmazie und Geowissenschaften, Johannes
¨
Gutenberg-Universitat, Duesbergweg 10-14,
55099 Mainz, Germany
e-mail: vboehmer@mail.uni-mainz.de
As starting material for the desired amino thiaca-
lix[4]arenes we envisaged their p-nitro- or p-azo-analogues,
from which the amino compounds finally should be avail-
able by reduction. To prepare their tetraethers, the more
reactive allylbromide (compared to alkyl bromides) was
chosen, since allyl ethers can be easily hydrogenated to
propylethers. However, in both cases we obtained the
tetrallyl ether in the 1,3-alternate conformation in
O. Kasyan
Institute of Organic Chemistry, NAS of Ukraine,
Murmanska Str. 5, Kyiv-94 02660, Ukraine
M. Bolte
Fachbereich Chemie und Pharmazeutische Wissenschaften,
Institut fu¨r Anorganische Chemie, Johann Wolfgang
¨
Goethe-Universitat, Max-von-Laue-Str. 7,
60438 Frankfurt/Main, Germany
123

J Chem Crystallogr (2011) 41:332–337
333
reasonable to good yield. This result, not entirely unex-
pected [10], may be explained by the observation that the
1,3-alternate conformation is already found for the 1,3-
diallylether (confirmed by a crystal structure [11]), in strong
contrast to 1,3-diethers of ‘‘normal’’ calix[4]arenes, which
prefer the cone conformation [12]. An explanation could be
the compensation of dipole-moments of the aromatic units
(nitrophenol and nitrophenylether) which might be stronger
than the stabilization via intramolecular hydrogen bonds
which usually determines the conformation of calix[4]arene
(derivatives). The tetraallyether in the 1,3-alternate con-
formation was also obtained for the unsubstituted thiaca-
lix[4]arene. (The 1,3-alternate conformation is not stable in
CDCl3 where it is slowly converted to the partial cone
conformation already at room temperature. A complete
transformation was achieved at 50 °C, where the partial
cone isomer seems to be stable.)
(3 9 5 mL) and dried for 1 h under vacuum (10 mmHg) at
100 °C. Compound 1 (0.24 g, 44%) was obtained as a
colorless powder. Mp = 210–214 °C. 1H NMR (400 MHz,
CDCl3, 25 °C): d 4.56 (m, 8H, OCH2), 4.73–4.96 (m, 8H,
CH=CH2), 5.64–5.77 (m, 4H, CH=CH2), 6.74 (t, 4H,
3
3JHH = 7.7 Hz, HAr), 7.34 (d, 8H, JHH = 7.7 Hz, HAr).
13C–{1H} NMR (100.6 MHz, CDCl3, 25 °C): d 69.6
(s, OCH2), 115.5 (s, CH=CH2), 123.1 (s, CAr), 129.0 (s,
CAr), 133.2 (s, CH=CH2), 134.2 (s, CAr), 159.4 (s, CAr). MS
(FD): m/z (%): 656.4 (100) [M]?, calcd for C36H32O4S4
656.91.
5,11,17,23-Tetranitro-25,26,27,28-tetraallyloxy-2,8,14,20-
thiacalix[4]arene (2)
Allylbromide (2.86 g, 2.1 mL, 23.70 mmol) was added to
the suspension of 5,11,17,23-tetranitro-25,26,27,28-
tetrahydroxy-2,8,14,20-thiacalix[4]arene [16] (0.40 g, 0.59
mmol) and Na2CO3 (2.51 g, 23.70 mmol) in dry acetoni-
trile (16 mL) and the reaction mixture was refluxed for
5 days with stirring. 1 N HCl was added (pH \ 7) and the
aqueous layer was washed with chloroform (4 9 30 mL).
The combined organic fractions were dried (MgSO4) and
evaporated. Diethyl ether (80 mL) was added and the
crystalline residue was filtered, washed with diethyl ether
(3 9 5 mL) and dried for 1 h under vacuum (10 mmHg) at
r.t. The compound thus obtained (0.21 g, 47%) as a brown
powder was identified as 5,11,17,23-tetranitro-25,27-dial-
lyloxy-2,8,14,20-thiacalix[4]arene [11]. Mp = 185–189 °C.
1H NMR (300 MHz, CDCl3, 25 °C): d 4.90 (d, 4H,
3JHH = 6.1 Hz, OCH2), 5.38–5.52 (m, 4H, CH=CH2),
6.10–6.27 (m, 2H, CH=CH2), 7.81 (s, 2H, OH), 8.05 (s, 4H,
HAr), 8.65 (s, 4H, HAr). 13C–{1H} NMR (100.6 MHz,
CDCl3, 25 °C): d 78.3 (s, OCH2), 121.1 (s, CH=CH2), 121.7
(s, CAr), 129.6 (s, CAr), 131.0 (s, CH=CH2), 131.4 (s, CAr),
132.6 (s, CAr), 140.3 (s, CAr), 144.1 (s, CAr), 162.6 (s, CAr),
163.6 (s, CAr). MS (FD): m/z (%): 756.2 (100) [M]?, calcd
for C30H20N4O12S4 756.77.
Experimental
General Experimental
1
Melting points are uncorrected. H and 13C NMR spectra
were recorded on a Bruker Avance DRX 400 spectrometer
at 400 and 100.6 MHz respectively. Chemical shifts are
reported in d units (ppm) with reference to the residual
solvent peaks. Mass spectra were recorded on a Waters/
Micromass QTof Ultima 3 mass spectrometer. All solvents
were HPLC grade and used without further purification.
As previously verified, [13, 14] data for elemental
analyses of organic calixarenes are often misleading, due to
inclusion of solvent molecules. Especially in the case of
isomers, they cannot be considered appropriate criteria of
purity. However, the identities of the reported compounds
were unambiguously established by their spectroscopic
data and their purity was controlled by TLC.
The mother liquor was evaporated and the residue was
triturated with acetone (10 mL). The insoluble part was
filtered off and acetone was evaporated. Finally diethyl
ether (10 mL) was added and the crystalline residue was
filtered, washed with diethyl ether (3 9 2 mL) and dried
for 2 h under vacuum (10 mmHg) at r.t. The tetraether 2
(0.05 g, 10%) was obtained as a colorless powder.
Mp = 161–165 °C. 1H NMR (400 MHz, CDCl3, 25 °C): d
4.57–4.98 (m, 16H, OCH2 and CH=CH2), 5.64–5.76 (m,
4H, CH=CH2), 8.27 (s, 8H, HAr); 13C–{1H} NMR
(100.6 MHz, CDCl3, 25 °C): d 70.3 (s, OCH2), 117.1 (s,
CH=CH2), 129.2 (s, CAr), 129.4 (s, CAr), 131.2 (s,
CH=CH2), 142.9 (s, CAr), 163.9 (s, CAr). MS (ESI): m/
z (%): 859.1 (100) [M ? Na]?, calcd for C36H28N4O12S4
836.90.
Syntheses
25,26,27,28-Tetraallyloxy-2,8,14,20-thiacalix[4]arene (1)
Allylbromide (2.86 g, 2.1 mL, 23.70 mmol) was added to
the suspension of 25,26,27,28-tetrahydroxy-2,8,14,20-thi-
acalix[4]arene [15] (0.40 g, 0.81 mmol) and Na2CO3
(2.51 g, 23.70 mmol) in dry acetonitrile (16 mL) and the
reaction mixture was refluxed for 7 days with stirring. 1 N
HCl was added (pH \ 7) and the aqueous layer was
extracted with chloroform (3 9 20 mL). The combined
organic fractions were dried (MgSO4) and evaporated.
Diethyl ether (25 mL) was added to the residue and the
formed solid was filtered, washed with diethyl ether
123

334
J Chem Crystallogr (2011) 41:332–337
3
4H, CH=CH2), 7.92 (d, 8H, JHH = 8.8 Hz, HAr), 8.04 (s,
5,11,17,23-Tetrakis(4-nitrophenylazo)-25,26,27,28-
tetraallyloxy-2,8,14,20-thiacalix[4]arene (3)
3
8H, HAr), 8.33 (d, 8H, JHH = 8.8 Hz, HAr). 13C–{1H}
NMR (100.6 MHz, CDCl3, 25 °C): d 70.0 (s, OCH2), 116.4
(s, CH=CH2), 123.3 (s, CAr), 124.8 (s, CAr), 128.8 (s, CAr),
129.7 (s, CAr), 131.9 (s, CH=CH2), 147.5 (s, CAr), 148.8 (s,
CAr), 155.5 (s, CAr), 162.2 (s, CAr). MS (FD): m/z (%):
1252.8 (100) [M]?, calcd for C60H44N12O12S4 1253.35.
Allylbromide (2.20 g, 1.6 mL, 18.30 mmol) was added to
the suspension of 5,11,17,23-tetrakis(4-nitrophenylazo)-
25,26,27,28-tetrahydroxy-2,8,14,20-thiacalix[4]arene [17]
(0.50 g, 0.46 mmol) and Na2CO3 (1.94 g, 18.30 mmol) in
dry acetonitrile (10 mL) and DMF (3 mL) and the reaction
mixture was refluxed for 3 days with stirring. 1 N HCl was
added (pH \ 7) and the aqueous layer was washed with
chloroform (3 9 100 ml). The combined organic fractions
were dried (MgSO4) and evaporated. Diethyl ether (50 mL)
was added to the residue and the formed precipitate was
filtered, washed with diethyl ether (3 9 3 ml) and dried for
1 h under vacuum (10 mmHg) at r.t. Compound 3 (0.41 g,
72%) was obtained as a brownish powder. Mp =
180–183 °C. 1H NMR (300 MHz, CDCl3, 25 °C): d
4.60–4.80 (m, 16H, OCH2 and CH=CH2), 5.58–5.74 (m,
Crystal Structures Determination
Crystal and data collection parameters are given in Table 1.
Data were collected on a STOE-IPDS-II two-circle dif-
fractometer employing graphite-monochromated Mo Ka
˚
radiation (k = 0.71073 A) with x-scans. Data reduction
was performed with the X-Area software [18]. An empirical
absorption correction was performed using the MULABS
[19] option in PLATON [20]. The structures were solved by
direct methods with SHELXS-90 [21] and refined by
Table 1 Crystallographic data
Compound
1
2
3
and refinement details for
compounds 1–3
CCDC deposition no.
766609
C36H32O4S4
656.86
766610
C36H28N4O12S4
836.86
766611
Empirical formula
Formula weight (g/mol)
Temperature (K)
C60H44N12O12S4
1253.31
173(2)
173(2)
173(2)
˚
Radiation type/k (A)
Mo Ka/0.71073
Trigonal
P3221
Mo Ka/0.71073
Orthorhombic
Pbca
Mo Ka/0.71073
Monoclinic
P21/n
Crystal system
Space group
Z
3
8
4
˚
a (A)
10.9608(4)
10.9608(4)
24.6730(12)
90
12.8608(4)
17.5209(5)
33.6527(9)
90
18.7825(19)
17.6662(13)
19.7828(18)
90
˚
b (A)
˚
c (A)
a (°)
b (°)
c (°)
90
90
114.152(7)
90
120
90
3
˚
Volume (A )
Calculated density (Mg/m3)
2567.07(18)
1.275
7583.1(4)
1.466
5989.6(9)
1.390
Absorption coeff. (mm-1
)
0.315
0.319
0.232
F(000)
1032
3456
2592
Crystal size (mm)
2hmax (°)
0.46 9 0.44 9 0.42
49.8
0.48 9 0.45 9 0.44
50.16
0.42 9 0.12 9 0.07
51.48
Reflections measured
Independent reflections
Rint
26,618
80,191
43,335
2953
6698
11,253
0.0406
0.0757
0.1765
Reflections with I [ 2r(I)
Data/restraints/parameter
Weighting schemea x/y
Goodness-of-fit on F2
R1 [I [ 2r(I)]
2875
5897
4176
2953/0/200
0.0469/0.2946
1.069
6698/0/516
0.0467/4.3387
1.027
11,253/56/803
0.1573/0.0
0.986
0.0243
0.0379
0.1188
wR2 [I [ 2r(I)]
wR2 [all data]
0.0668
0.0962
0.2501
0.0678
0.1002
0.3422
w = 1/[r2(F2o) ? (x 9 P)2 ?
3
a
˚
Dqmax (e/A )
0.293
0.324
1.420
y 9 P]; P = (F2o ? 2Fc2)/3
123

J Chem Crystallogr (2011) 41:332–337
335
˚
full-matrix least-squares techniques with SHELXL-97 [21].
All non-H atoms were refined with anisotropic displacement
parameters. Hydrogens bonded to C were included at cal-
culated positions and allowed to ride on their parent atoms.
In 2 and 3, one terminal vinyl group is disordered over two
positions. For 3 restraints were used to keep the geometric
parameters of some moieties in a reasonable range.
Table 2 Selected distances (A) and angles (°) for compounds 1–3
1
2
3
Distances
O12–O32a
O22–O42a
C15–C35a
C25–C45a
4.965
4.900
6.379
6.358
–
4.744
4.341
6.566
6.474
7.079
6.979
5.538
5.578
5.588
5.541
7.864
7.862
5.169
5.062
6.157
5.590
6.480
5.587
5.546
5.540
5.548
5.559
7.777
7.913
N15–N35
Results and Discussion
N25–N45
–
S1–S2
S2–S3a
S3a–S4a
5.555
5.579
5.555
5.579
7.780
7.945
X-ray crystal structures could be obtained for the three
thiacalix[4]arene tetraallyl ethers (1–3, Fig. 1) in the
1,3-alternate conformation. Single crystals of 1 and 2 (p-H,
p-NO2) were obtained by slow evaporation of a solution in
acetone and of a chloroform solution in the case of the
tetraazo compound 3. No solvent was included in the
crystal in all cases.
S4–S1
S1–S3a
S2–S4a
Bond angles
C11–S1–C43
C21–S2–C13
C31–S3–C23
C41–S4–C33
S1–S2–S3
104.4
104.0
104.4
104.0
88.7
102.6
104.7
106.0
104.2
90.1
102.6
101.5
103.3
102.8
89.1
The molecular shape of the thiacalix[4]arene part is
similar for all three compounds (and similar to other tet-
raethers of thiacalixarenes in the 1,3-alternate conforma-
tion) [22, 23]. The aromatic rings are bent slightly
outwards, including angles of 80° (1), 72–82° (2) and
81–88° (3) with the molecular main plane, defined by the
four sulfur atoms. For all compounds bond lengths and
bond angles are in the usual range. Characteristic distances
and angles are collected in Table 2. The shape of the three
molecules is compared in Fig. 2.
S2–S3–S4
91.1
89.5
91.1
S3–S4–S1
88.7
89.9
88.9
S4–S1–S2
91.1
90.4
90.9
Angles between planes
m.p./C11–C16
m.p./C31–C36
m.p./C21–C26
m.p./C41–C46
C11–C16/C31–C36
C21–C26/C41–C46
80.0
80.0
80.2
80.2
19.93
19.60
81.6
73.8
72.0
81.5
24.6
26.5
85.0
81.2
88.0
87.2
13.8
4.9
In an ideal 1,3-alternate conformation, the four sulfur
atoms should be placed on the corners of a regular square.
This is (practically) the case for all compounds, since the
˚
distance between adjacent S-atoms differs by 0.024 A for
˚
˚
1, by max 0.05 A for 2 and by max 0.017 A for 3. The
˚
length of the diagonals differs by 0.165 A for 1 (indicating
˚
a rhombic shape) and by 0.133 A for 3, while practically
m.p. main plane, defined by the four S-atoms
a
For 1: O32, O42, C35, C45, S3, S4 are the symmetry equivalents of
O12, O22, C15, C25, S1, S2, respectively
no difference exists for 2.
For comparison the diagonal distance of the phenolic
˚
oxygenes (O12–O32 and O22–O42) is distinctly larger for
˚
D = 0.565 A for 3 cannot be only due to the lower quality
˚
2 (D = 0.403 A) than for 1 (D = 0.065 A) and 3
of this crystal structure. As can be seen in Fig. 2, this lower
quality of 3 is mainly due to disorder in the azophenyl
residues while the accuracy of the 1,3-alternate core is
similar to 1 and 2.
˚
(D = 0.11 A), an order which is not reflected for carbon
atoms in p-position of the phenolic units (opposite to the
˚
phenolic oxygen), which differ by D = 0.021 A for 1 and
˚
The slight difference in the 1,3-alternate conformation
of the three compounds is evidenced best by the angle
between opposite aromatic rings of the calixarene skeleton.
It is slightly higher (24.6°/26.5°) for 2 than for 1 (19.9°/
19.6°) and lowest for 3 (14°/5°), where both values also
show the strongest deviation.
D = 0.092 A for 2, while the larger difference of
R
R
1
R = H
S
Y
2 R = NO2
O
O
Y
S
S
N
N
NO2
3
R =
Y =
Y
O
An interesting packing is found for compound 1. As
shown in Fig. 3 three layers of parallel columns or tubes
are found which extend along the a-axis, the diagonal in
the a,b-plane (the plane formed by the a- and b-axis) and
the b-axis. This means, that these positions may be
O
Y
S
R
R
Fig. 1 Molecular structures of compounds 1–3
123

336
J Chem Crystallogr (2011) 41:332–337
Fig. 2 Comparison of the molecular shape of compounds 1–3. Hydrogen atoms are omitted for clarity
Fig. 3 Packing of molecules 1,
seen a along the a-axis, b along
the ‘‘a–b’’ diagonal and c along
the b-axis
interconverted by turning around the c-axis. Similar col-
umns or tubes are formed by compound 3, but in this case
all tubes are parallel to the a-axis (Fig. 4b). Such an
alignment of the molecular axes (perpendicular to the
reference plane defined by the S-atoms) is not found in the
crystal lattice of 2. Here the packing is best described by
123

J Chem Crystallogr (2011) 41:332–337
337
Fig. 4 Packing of molecules
a 2 and b 3 seen along the
a-axis
¨
5. Mogck O, Bohmer V, Vogt W (1996) Tetrahedron 52:8489–8496
6. Castellano RK, Rebek J Jr (1998) J Am Chem Soc 120:
3657–3663
layers of molecules parallel to the a, b-plane, as shown in
Fig. 4a.
7. Rudzevich Y, Rudzevich V, Moon C, Schnell I, Fischer K,
¨
Bohmer V (2005) J Am Chem Soc 127:14168–14169
¨
8. Rudzevich Y, Rudzevich V, Moon C, Brunklaus G, Bohmer V
(2008) Org Biomol Chem 6:2270–2275
Supplementary Material
´
9. Lhotak P (2004) Eur J Org Chem 1675–1692
10. Lang J, Vlach J, Dvorakova H, Lhotak P, Himl M, Hrabal R,
Stibor I (2001) J Chem Soc Perkin Trans 2:576–580
¨
11. Kasyan O, Thondorf I, Bolte M, Kalchenko V, Bohmer V (2006)
Acta Crystallogr C62:o289–o294
CCDC-766609, CCDC-766610 and CCDC-766611 contain
the supplementary crystallographic data for this paper.
These data can be obtained free of charge via www.ccdc.
cam.ac.uk/data_request/cif, or by emailing data_request@
ccdc.cam.ac.uk, or by contacting The Cambridge Crystal-
lographic Data Centre, 12 Union Road, Cambridge CB2
1EZ, UK; fax: ?44(0)1223-336033.
ˇ´
´
´
¨
12. Bohmer V (2003) In: Rappoport Z (ed) Chemistry of phenols.
Wiley, Chichester, pp 1369–1454
¨
¨
13. Bohmer V, Kai J, Schon M, Wolff A (1992) J Org Chem
57:790–792
14. Sansone F, Barboso S, Casnati A, Fabbi M, Pochini A, Ugozzoli F,
Ungaro R (1998) Eur J Org Chem 897–905
15. Akdas H, Bringel L, Graf E, Hosseini MW, Mislin G, Pansanel J,
De Cian A, Fischer J (1998) Tetrahedron Lett 39:2311–2314
16. Desroches C, Parola S, Vocanson F, Perrin M, Lamartine R,
Acknowledgments This work was supported by the Deutsche
Forschungsgemeinschaft (Bo 523/14-4, SFB 625) and by the Euro-
pean Commission (Contract No. FI6W-CT-2003-508854). O. K. is
especially grateful for the fellowship (Contract No. 012722-FI6 W).
´
´
Letoffe JM, Bouix J (2002) New J Chem 26:651–655
17. Desroches C, Parola S, Vocanson F, Ehlinger N, Miele P, La-
martine R, Bouix J, Eriksson A, Lindgren M, Lopes C (2001) J
Mater Chem 11:3014–3017
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