p-t-Butyl Calix[4]crown-4 and Double Calix[4]arene Dimer
347
Chemicals
and were modelled with two positions and occupation factors
set to 0 5. Some constraints on bond lengths and angles were
applied on the disordered fragments. All non-hydrogen atoms
were re ned anisotropically except those of the disordered
fragments. Hydrogen atoms were introduced at calculated
positions (except for OH groups, disordered atoms and solvent
molecules) and constrained to ride their parent carbon atom
with isotropic thermal parameters equal to 1 2 (CH, CH2) or
1 5 (CH3) times that of the parent atom.
Triethylene glycol ditosylate (Aldrich) was used as received.
All commercial solvents and basic reagents were also used
without puri cation. p-t-Butylcalix[4]arene was prepared as
described in ref. 13.
Preparation of (1) and (2)
p-t-Butylcalix[4]arene (19 47 g, 30 0 mmol) and potassium
carbonate (4 15 g, 30 0 mmol) were stirred at room temper-
ature in acetonitrile (1500 ml) for 3 h. Triethylene glycol
ditosylate (15 13 g, 33 0 mmol) was added as a solid and
the mixture was then heated to re ux. After 7 days the
solvents were evaporated to dryness. The residue was acidi ed
with 1 M HCl, and the aqueous phase was extracted with
dichloromethane. The organic layer was dried over sodium
sulfate, ltered and evaporated. After evaporation, the residue
was chromatographed on a silica column with dichloromethane
as eluent. Calixcrown-4 (1) (RF 0 7; 11 87 g, 52%) was rst
eluted pure as a white solid (m.p. 195–196 C). Then, pure
double calix[4]arene double crown-4 (2) (RF 0 6; 3 46 g, 15%)
was isolated as another white solid (m.p. 168–169 C).
Crystal data for (1).CH3OH.CH3CN: C53H73N1O7 (formula
for a complete molecular unit, but only half a molecule in the
asymmetric unit), M r 836 12, trigonal, space group P 3221,
a 12 5654(3), c 28 1217(3) A, V 3845(2) A3, Z 3, Dc 1 083
3
g cm
,
0 070 mm 1, F(000) 1362. The results of the
structure re nement, not quite satisfying due to low crystal
quality, are not given here.
Crystal data for (2).2CH3OH.4CHCl3: C106H144Cl12O14
,
M r 2067 58, triclinic, space group P 1, a 12 9861(12), b
15 4868(15),
70 781(2) ,
0 358 mm
c
V
29 144(3) A,
5528(3) A3,
, F(000) 2184, crystal size 0 30 by 0 25 by
87 494(2),
2, Dc 1 240
88 122(3),
3
Z
g
cm
,
1
0 25 mm, 19137 unique re ections used, 1210 parameters
re ned, R 0 141, S 1 13. Some t-butyl groups and some parts
of the ether chains were disordered over two or three positions
and were re ned with occupation factors constrained to sum
to unity. Three out of four chloroform molecules were also
highly disordered and modelled with up to ve chlorine atoms.
Some constraints on bond lengths and angles were applied
on the disordered fragments. All non-hydrogen atoms were
re ned anisotropically except those of the disordered solvent
molecules. Hydrogen atoms were introduced at calculated
positions (except for OH groups, disordered atoms and solvent
molecules) and constrained to ride their parent carbon atom
with isotropic thermal parameters equal to 1 2 (CH, CH2) or
1 5 (CH3) times that of the parent atom. The highest residual
density peak (1 2 e A 3) is located near a badly resolved
chloroform molecule.
Final atomic parameters and equivalent thermal parameters
are given in Tables 1 and 2, and molecular drawings, done
with SHELXTL,16 in Figs 1 and 2. Bond lengths and angles
lie in the usual range. Material deposited includes Tables of
structure factor amplitudes, interatomic distances and angles,
anisotropic thermal parameters and hydrogen atom coordinates
in CIF format (copies are available, until 31 December 2004,
from the Australian Journal of Chemistry, P.O. Box 1139,
Collingwood, Vic. 3066).
Analytical Data for (1)
1H n.m.r. (200 MHz, CDCl3, in ppm from SiMe4, J in
Hz) 8 68, s, 2H, ArOH; 7 05, s, 4H, ArH meta; 6 97, s, 4H,
ArH meta; 4 36, d, JAB 13 0 Hz, 4H, ArCH2Ar; 4 17, s
large, 8H, ArOCH2CH2O; 3 97, s, 4H, OCH2CH2O; 3 33, d,
JAB 13 0 Hz, 4H, ArCH2Ar; 1 20, s, 18H, C(CH3)3; 1 18, s,
18H, C(CH3)3. F.a.b. mass spectrum (+) m/z 762 7. Found:
C, 75 3; H, 8 4. C50H66O6.0 5CH2Cl2 requires C, 75 3; H,
8 4%.
Analytical Data for (2)
1H n.m.r. (200 MHz, CDCl3, in ppm from SiMe4, J in Hz)
7 32, s, 4H, ArOH; 7 01, s, 8H, ArH meta; 6 74, s, 8H, ArH
meta; 4 33, d, JAB 13 0 Hz, 8H, ArCH2Ar; 4 03, s large, 16H,
OCH2CH2O; 3 24, d, JAB 13 0 Hz, 8H, ArCH2Ar; 1 24, s,
36H, C(CH3)3; 0 91, s, 36H, C(CH3)3. F.a.b. mass spectrum
(+) m/z 1526 3. Found: C, 78 5; H, 8 5.
requires C, 78 7; H, 8 7%.
C108H132O12
Crystal Structure Determinations
Crystals of solvates of (1) and (2), of rather low qual-
ity but suitable for X-ray crystallography, were obtained
from slow evaporation of CHCl3/CH3OH (1 : 1) solutions, and
sealed in Lindemann capillaries [recrystallization of (1) from
a CH3OH/CH3CN (1 : 1) solution led to another form, for
which the structure re nement was less satisfying]. Crystals
of (2) were particularly unstable, readily losing their crystal-
lization solvent, a problem which was overcome by using low
temperatures for data recording (123 K for both compounds).
Data were recorded on a Nonius Kappa-CCD area-detector
di ractometer; graphite monochromatized Mo K radiation
was used. The crystal-to-detector distance was set to 29 mm for
both compounds, and the unit cells were determined from all
the re ections measured on 10 plates ( rotation with 1 steps).
Results and Discussion
The reaction leading to (1) and (2) is presented in
Scheme 1.
The condensation reaction was conducted according
to a similar procedure prescription described elsewhere
for related compounds.17 After workup, the residue
was chromatographed on silica to a ord (1) and (2) as
1
white solids in 67% total yield. The H n.m.r. spectra
A 180
range was scanned during data recording (90 plates,
rotation with 2 steps). The data were processed with the HKL
package;14 the structures were solved by direct methods with
SHELXS8615 and re ned on F2 with SHELXTL.16 No absorption
correction was made. Special details are given below.
of calixcrowns (1) and (2) were very similar, and
presented the same integration ratio of calixarene unit
to glycol chain. The only di erence was the presence
of a singlet at 4 17 ppm for the central OCH2CH2O
protons in the spectrum of (1), a feature which cannot
be distinguished in the spectrum of (2). This could
probably be due to a more constrained bridging in
(1) if corresponding to the 1+1 condensation product.
F.a.b. mass spectrometry showed that (1) corresponded
to a 1+1 condensation product and (2) to its dimer.
Crystal data for (1).2CHCl3: C104H136Cl12O12 (Z = 2,
two molecules in the asymmetric unit), M r 2003 53, triclinic,
space group P 1, a 12 4725(8), b 19 0396(12), c 23 2382(9) A,
69 683(2),
Dc 1 286 g cm
89 870(2), 89 127(2) , V 5174(3) A3, Z 2,
,
3
0 379 mm 1, F(000) 2120, crystal size
0 24 by 0 24 by 0 18 mm, 18940 unique re ections used, 1162
parameters re ned, R 0 123, S = 1 06. Some atoms in the
t-butyl groups and the solvent molecules were found disordered
Asfari, Zouhair
