Formation of huge cyclic oligomers in the condensation polymerization of bis(9-hydroxy-1,4,7-trioxanonyl) substituted naphthalene and benzenes with both aromatic and aliphatic bis-acid chlorides

Article abstract of DOI:10.1039/a701920c

Without the use of high dilution techniques condensation polymerization of bis(9-hydroxy-1,4,7-trioxanonyl) substituted naphthalene and benzenes (1a-d) with the bis-acid chlorides terephthaloyl dichloride (2), adipoyl dichloride (5a) and isophthaloyl dich

Full text of DOI:10.1039/a701920c

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Formation of huge cyclic oligomers in the condensation
polymerization of bis(9-hydroxy-1,4,7-trioxanonyl) substituted
naphthalene and benzenes with both aromatic and aliphatic bis-acid
chlorides
Ingrid J. A. Mertens,a René Wegh,a Leonardus W. Jenneskens,*,a
Edward J. Vlietstra,a Anca van der Kerk-van Hoof,b Jan W. Zwikker,a
Thomas J. Cleij,a Wilberth J. J. Smeets,c Nora Veldmanc and Anthony L. Spekc
a Debye Institute, Department of Physical Organic Chemistry, Utrecht University, Padualaan 8,
3584 CH Utrecht, The Netherlands
b Bijvoet Center for Biomolecular Research, Department of Mass Spectrometry,
Utrecht University, PO Box 80083, 3508 TB Utrecht, The Netherlands
c Bijvoet Center for Biomolecular Research, Department of Crystal- and Structural Chemistry,
Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
Without the use of high dilution techniques condensation polymerization of bis(9-hydroxy-1,4,7-
trioxanonyl) substituted naphthalene and benzenes (1a–d) with the bis-acid chlorides terephthaloyl
dichloride (2), adipoyl dichloride (5a) and isophthaloyl dichloride (5b) at 80 ЊC, respectively, gives giant-
size macrocycles, i.e. crownophanes 3a(n) with n ؍ 1–5, 3b–d(n) with n ؍ 1–3 and 6a–b(n) with n ؍ 1–2,
respectively, in high overall yield (ca. 30% w/w, monomer conc. 0.033 M). The crownophanes with 28–150
atom perimeters have been isolated using preparative column chromatography. Both in the melt and in
solution, with a ten-fold increase in monomer conc. (0.33 M), cyclic oligomer yields remain considerable
(melt, ca. 2% w/w, and solution ca. 10% w/w). 1H NMR conformational analysis of the 9-hydroxy-1,4,7-
trioxanonyl side chains of both 1a and 1d at 25 and 80 ЊC have shown that all HO᎐[CH(I)2᎐CH(II)2᎐O]n᎐
units are almost exclusively present in their gauche conformation at both temperatures. This is supported
by semi-empirical AM1 calculations. Hence, favourable pre-orientation of the side chains is apparently an
important factor in the formation of cyclic oligomers. Single crystal X-ray structures of 3a(1), 3d(1) and
6a(1) are reported; solid-state packing motifs are strongly affected by the type of diol and bis-acid
constituent.
respectively, Scheme 1, vide infra). It should be stipulated that
Introduction
no high dilution conditions4 were applied! The work presented
in this paper was initiated to elucidate the following issues.
(i) To what extent is cyclic oligomer formation during con-
densation polymerization of bis(9-hydroxy-1,4,7-trioxanonyl)
substituted aromatics 1a–d with the bis-acid chlorides tere-
phthaloyl dichloride (2), adipoyl dichloride (5a) and isophthal-
oyl dichloride (5b), affected by the structural flexibility and
topology of the diols as well as the bis-acid chlorides? (ii) What
are the factors responsible for the cyclic oligomer formation?
Although it is well established that during condensation poly-
merizations,1 in addition to formation of linear polymers, cyclic
oligomers are generated as side products,2 under common con-
ditions (ratio diol:bis-acid 1:1, either in the melt or in solution)
the cyclic oligomer yield is invariably low (ca. 1–5% w/w). Con-
sequently, only a small number of cyclic oligomers have been
isolated and characterized. This is unfortunate since they can be
used to assess differences as well as similarities between cyclic
and linear oligomers versus the polymer. Furthermore, if
ligating sites such as HO᎐[CH()2᎐CH()2᎐O]n᎐ units are pres-
ent, cyclic oligomers serve as model systems to mimic natural
compounds such as ionophores.3 To obtain large cyclic oligo-
mers, the most widely used method is the high dilution tech-
nique, i.e. condensation reactions are carried out under high
dilution conditions.4 Although this reduces the probability of
polymerization, cyclic oligomer yields in general remain low
(ca. 15% w/w).5 Other approaches are the use of (self)-organiz-
ation through molecular recognition of reactants, the applic-
ation of multiple cycloadditions and via immobilization of the
reactants on solid substrates.6–8
Results and discussion
Formation and isolation of cyclic oligomers
Condensation polymerization was performed with 1,5-bis(9-
hydroxy-1,4,7-trioxanonyl)naphthalene (1a) and ortho, meta
and para bis(9-hydroxy-1,4,7-trioxanonyl) substituted benzenes,
viz. 1,2-bis(9-hydroxy-1,4,7-trioxanonyl)benzene (1b), 1,3-bis(9-
hydroxy-1,4,7-trioxanonyl)benzene (1c) and 1,4-bis(9-hydroxy-
1,4,7-trioxanonyl)benzene (1d), respectively, with terephthaloyl
dichloride (2, Scheme 1, monomer conc. 0.033 ). Evidence
for the formation of a distinct series of cyclic oligomers was
obtained from an analysis of the crude reaction mixtures of 1a–
d/2, using thin layer chromatography (TLC) and gel permeation
chromatography (GPC). TLC revealed the presence of at least
three low molecular weight components, which migrated, in
contrast to the high molecular weight material. Precipitation
of the high molecular weight fraction of 1a–d/2 in a five-fold
excess of methanol followed by GPC analysis of both the vis-
In a recent communication we have reported on the form-
ation of huge macrocyclics, i.e. crownophanes9 3a(n) with n =
1–5, during condensation polymerization of 1,5-bis(9-hydroxy-
1,4,7-trioxanonyl)naphthalene (1a) with terephthaloyl dichlor-
ide (2).10 Both in the melt and in solution (monomer conc.
either 0.33 or 0.033 ), a homologous series of cyclic oligomers
3a(n) is formed in addition to the linear polymer 4a in consider-
able amounts (2, 10 and 30% w/w for melt, 0.33 and 0.033 ,
J. Chem. Soc., Perkin Trans. 2, 1998
725

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O
Cl
O
O
O
O
O
OH
O
O
O
O
O
O
O
O
O
O
C
O
C
2
2
2
O
m
i
+
+
HO
O
O
O
Cl
O
n
2
2
2
3a–d(n)
1a–d
2
4a–d
= a :
b :
c :
and d :
Where
Scheme 1 Reagents and conditions: i, 1,2-dichloroethane, pyridine, reflux
Fig. 1 GPC trace of the low molecular weight fraction containing
3a(n) with n = 1–5
Fig. 2 Aromatic part of the 1H NMR spectra of 3a(1) and 3a(2)
[* terephthaloyl protons]
cous precipitate and the methanol-soluble fraction, showed that
the low molecular weight compounds are soluble in methanol;
in the case of the methanol-soluble fraction of 1a/2 at least four
major products were observed (Fig. 1). Furthermore, the GPC
retention times [tR(GPC)] found within each series suggest that
the low molecular weight compounds are structurally related.
On the basis of the polystyrene calibration curve, consecutive
mass increments of ca. 550 [3a(n)] and 500 [3b–d(n)] amu con-
comitant with increasing n were found. For their preparative
isolation a two step column chromatography (silica gel; eluent
acetone–n-hexane 1:1 v/v) procedure was used in the case of
3a(n). While 3a(1) and 3a(2) could be isolated directly from the
concentrated methanol-soluble fraction, 3a(3–5) were obtained
as a mixture. The latter were separated in a second preparative
column chromatography run (silica gel; eluent acetone–n-
hexane 1:1 v/v). Compounds 3b(1–3), 3c(1,2) and 3d(1–3) were
isolated in a single preparative column chromatography (silica
gel; eluent acetone–n-hexane 1:1 v/v) run. High-performance
liquid column chromatography (HPLC) showed that the iso-
lated compounds within each series possess different retention
times [tR(HPLC)] and purities exceeding 95% (Tables 1 and
2). Note that the isolated yields for 3b–d(n) with n = 1–3 were
higher than those of 3a(n) with n = 1–5. However, HPLC
analysis of the crude low molecular weight fractions revealed
that the amount of cyclic oligomers obtained during each con-
densation polymerization is nearly identical in every series.
Therefore, we conclude that the preparative column chrom-
atography procedure applied for the isolation of compounds
3a(n) is apparently not as effective as in the case of 3b–d(n).
However, the simplicity of the isolation procedure and its suit-
ability for scaling up enables the isolation of 3a(n) with n = 1–5
in reasonable amounts.
Characterization of cyclic oligomers
It should be stipulated that within each series the elemental
composition of the cyclic oligomers is identical, since they all
consist of n times the diol and the bis-acid moiety in a 1:1 ratio.
1
Indeed, H NMR spectroscopy unequivocally showed that all
the isolated compounds consist of coupled monomers in a 1:1
ratio. Neither hydroxy nor carboxylate endgroups were dis-
cernible (1H NMR and FTIR spectroscopy). 1H NMR and 13
C
NMR spectroscopy revealed that all spectra within each series
are virtually identical with the exception of the 1H NMR spec-
tra of 3a–d(1). For example, in the case of 3a(1) an upfield shift
for the terephthaloyl protons (∆δ Ϫ0.40)10 is observed, which
1
is not discernible in the H NMR spectra of 3a(n) with n у 2
(Fig. 2).† This suggests that in solution the terephthaloyl pro-
tons of 3a(1) are positioned in the shielding cone region of the
bis-substituted naphthalene moiety (see single crystal X-ray
structure determinations). These spectroscopic data strongly
indicate that the isolated compounds are cyclic oligomers with
increasing values of n. This is corroborated by FABMS; con-
† In the case of 3b–d(1) no clear shielding cone effects are discernible;
only moderate upfield shifts (ca. ∆δ Ϫ0.03) are found.
726
J. Chem. Soc., Perkin Trans. 2, 1998

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Table 1 Salient features of cyclic oligomers 3a(n)10
tR(GPC)/
min
tR(HPLC)/
min
Yield (HPLC)
(% w/w)
Isolated yield
[% w/w (purity)]
FABMS
DSC Tm (Tg) b/
ЊC
Ring
Sizea
([MϩH]ϩ)
3a(1)
3a(2)
3a(3)
3a(4)
3a(5)
30
60
90
120
150
11.13
10.71
10.48
10.25
10.09
5.31
21.9
4.7
1.0
0.2
0.2
10.3 (>99%)
3.2 (>99%)
1.2 (>99%)
1.2 (>95%)
0.1 (>95%)
555
1109
1663
2217
2771
116.7c
125.0c
(0.5)
(0.0)
—
9.82
11.80
12.93
14.53
a Size represents the number of atoms determining the ring perimeter. b Melting points; peak maximum taken from the second heating run. Glass
transition temperatures (Tg) are midpoint values. c For melt enthalpies ∆H in cal gϪ1; see Experimental section.
Table 2 Salient features of cyclic oligomers 3b–d(n)
tR(GPC)/
min
tR(HPLC)/
min
Isolated yield
[% w/w (purity)]
FABMS
DSC Tm (Tg)/
ЊC
Ring
Sizea
[MϩH]ϩ
3b(1)
3b(2)
3b(3)
3c(1)
3c(2)
3c(3)
3d(1)
3d(2)
3d(3)
28
56
84
29
58
87
30
60
90
11.09
10.65
10.42
11.10
10.69
10.47
11.08
10.80
10.44
3.74
6.96
9.08
4.12
7.47
9.51
3.76
7.15
9.11
30 (>99%)
5 (>99%)
1 (>95%)
21 (>99%)
3 (>96%)
e
23 (>99%)
4 (>98%)
1 (>95%)
505
1009
1513
505
1009
1513
505
80.7b( Ϫ 17.5)c
111.1b( Ϫ 11.2)c
(Ϫ23.3)
98.6b
74.2b (Ϫ7.2)d
f
91.6b (Ϫ8.8)c
1009
1513
115.3b
f
a Size represents the number of atoms determining the ring perimeter. b For melt enthalpies ∆H in cal gϪ1; see Experimental section. c No crystalliz-
ation occurs during its cooling run; in the second heating run a glass transition [Tg (midpoint value)] is found, followed by cold crystallization and
again the melting process upon further heating. d No crystallization occurs during its cooling run; in the second heating run only a glass transition
(Tg) is found. e Not isolated. f Not determined.
C
O
O
O
O
O
O
O
O
O
C
O
8
O
O
O
O
C
O
C
O
O
O
O
9
comitant with increasing n [MϩH]ϩ molecular ions are found
which differ by consecutive 554 [3a(n)] and 504 [3b–d(n)] amu
increments (Tables 1 and 2). A characteristic loss of (multiple)
C2H4O (44 amu) fragments directly from [MϩH]ϩ is found
for macrocycles containing coupled ethylene glycol units.11,12
Although the linear reference compounds 8 and 9 ([MϩH]ϩ =
583) also show loss of C2H4O units, this never occurs directly
from the molecular ion, i.e. no fragment ion with m/z 539 is
found. Hence, huge cyclic oligomers are indeed obtained. For
3a(1), 3d(1) and 6a(1) this is further supported by single crystal
X-ray structure determinations (vide infra).
The thermal properties of the crownophanes were assessed
using differential scanning calorimetry (DSC) and polarization
microscopy. Whereas all compounds with n = 1 and 2 are crys-
talline solids, those with n > 2 only possess a glass transition.
No (thermotropic) liquid crystalline behaviour was observed
(Tables 1 and 2). To determine if intramolecular interactions
between the incorporated bis-substituted naphthalene and
phenyl moieties occur cyclic voltammetry measurements were
made. For the bis-substituted naphthalene moiety in 1a and
3a(n) only an irreversible one-electron oxidation (anodic peak
potential, Epa 1.05 V) was observed. In the case of the phenyl
derivatives an irreversible one-electron oxidation was also
found [Epa, 1b and 3b(n) 1.41 V; 1c and 3c(n) 1.53 V; 1d and
3d(n) 1.19 V]. For all compounds an irreversible one-electron
reduction wave (Epc Ϫ1.88 V) was obtained for the tereph-
thaloyl unit, which corresponds to the Epc value (Ϫ1.85 V) of
dimethyl terephthalate. Since within each series Epa and Epc
values are essentially identical, no interactions between the
redox-active moieties are discernible. This is supported by UV–
VIS spectroscopy, viz. the spectra of the cyclic oligomers are
identical to sum spectra obtained for equimolar mixtures of
appropriate reference compounds such as 1a and dimethyl
terephthalate; no additional charge transfer13 absorption bands
are found.
Cyclic oligomer yield
To determine whether the nature and the geometry of the bis-
acid moiety affects the formation of cyclic oligomers, adipoyl
dichloride (5a) and isophthaloyl dichloride (5b) were used as
bis-acid chlorides in condensation polymerization reactions
with diol 1a (monomer conc. 0.033 , Scheme 2). From the
crude fractions containing low molecular weight material of 1a/
5a and 1a/5b the cyclic oligomers 6a(1,2) and 6b(1,2), respect-
ively, were readily isolated using the preparative column chro-
matography procedure (Table 3). Note, however, that no higher
homologues, viz. 6a(n) and 6b(n) with n > 2, could be identified.
Compared to the results obtained for polycondensation of 1a
and 2 under identical conditions, similar overall cyclic oligomer
yields were found with both adipoyl dichloride (5a) and iso-
phthaloyl dichloride (5b) (Tables 1 and 3).
Therefore, we subsequently investigated to what extent the
overall cyclic oligomer yields are affected by the monomer con-
centration during polycondensation. Condensation polymeriz-
J. Chem. Soc., Perkin Trans. 2, 1998
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Table 3 Salient features of cyclic oligomers 6a(n) and 6b(n)
tR(GPC)/
tR(HPLC)/
min
Yield (HPLC)
(% w/w)
FABMS
DSC Tm (Tg)/
ЊC
Ring
Sizea
min
[MϩH]ϩ
6a(1)b
6a(2)b
6b(1)b,e
6b(2)b,e
32
64
29
58
11.16
10.78
11.03
10.63
4.39
8.06
6.42
16.4
4.9
19.5
4.8
535
1069
555
100.7c
52.5c (Ϫ18.4)d
82.2c (0.7)d
120.5c (11.9)d
10.72
1109
a Size represents the number of atoms determining the ring perimeter. b Compounds 6a,b(n) with n = 1 and 2 were isolated by preparative column
chromatography. c For melt enthalpies ∆H in cal gϪ1; see Experimental section. d No crystallization during its cooling run; in the second heating run
only a glass transition (Tg) is found. e HPLC 6b(n); elution velocity 0.8 ml minϪ1 (see Experimental section).
Table 4 Cyclic oligomer yield under concentrated conditions
Yield (HPLC)
tR(HPLC)/ [solution 0.33 
O
O
OH
Yield (HPLC)
[melt (% w/w)]
2
O
Cl
Ringa
Sizeb
min
(% w/w)]
+
3a(1)
3a(2)
3a(3)
3a(4)
3a(5)
3d(1)
3d(2)
3d(3)
30
60
90
120
150
30
5.38
8.7
2.3
0.6
0.2
c
8.0
2.4
1.0
1.7
0.3
c
c
c
1.0
0.9
c
9.81
11.78
12.92
c
3.78
7.18
9.18
HO
O
O
Cl
O
2
60
90
5 a–b
1a
a For the physical properties of 3a(n) with n = 1–5 and 3d(n) with n =
1–3 see Tables 1 and 2, respectively. b Size represents the number of
atoms determining the ring perimeter. c Not observed with HPLC in the
crude reaction mixture [for series 3a(n) see also Table 1].
i
O
under high dilution conditions cyclic oligomer yields do not
exceed 15% w/w yield,5 these yields are still considerable.
O
O
O
2
GPC analysis of the high molecular weight fraction after
precipitation shows a decrease in molecular weight (Mr) for the
polymers 4(a–d) in going from melt to solution condensation
polymerization conditions with decreasing monomer concen-
trations. For example, molecular weight distributions (GPC) of
polymers 4a and 4d decrease from Mr 2 × 104 and 3 × 104 in the
melt, to Mr 1.4 × 104 and 3.5 × 103 in solution using monomer
concentrations of 0.33 and 0.033 , respectively.‡ Hence, the
weight fraction of cyclic oligomers increases with decreasing
concentration of the monomers in the reaction mixture. This
is attributed to the different dependence of intramolecular
cyclization (first-order kinetics) versus intermolecular reactions
(second-order kinetics) upon monomer concentrations.5
As discussed above, charge-transfer interactions do not
appear to play an important role according to cyclic voltam-
metry and UV–VIS measurements. A more appealing explan-
ation is provided by 1H NMR conformational analysis14 of the
9-hydroxy-1,4,7-trioxanonyl side chains of 1a and 1d. As an
illustration part of the aliphatic region of the experimental and
simulated 1H NMR spectrum of the 9-hydroxy-1,4,7-tri-
oxanonyl chain of 1d (C2D2Cl4, 80 ЊC) is presented in Fig. 3 (see
Experimental section). In line with reported data15 for oligo-
and poly-(ethyleneglycols) the HO᎐[CH()2᎐CH()2᎐O]n᎐ units
are present almost exclusively in their gauche conformation at
25 and 80 ЊC. The latter result is of interest since solution con-
densation polymerization is performed at 80 ЊC. In Table 5,
the gauche populations (xg) of the consecutive HO᎐[CH()2᎐
CH()2᎐O]n᎐ units starting at the hydroxy functionality are
reported. These results are corroborated by semi-empirical
AM116 calculations on 1a and 1d. For both compounds minima
were identified which are close in energy (∆fH0) corresponding
to conformers possessing curved 9-hydroxy-1,4,7-trioxanonyl
side chains in either an up-up or up-down relationship (Fig. 4).
Whereas for 1a two minima were found (up-up with C2 sym-
O
O
O
O
n
2
6 a–d
+
O
O
C
O
O
O
C
2
m
O
O
O
2
7a–d
a :
= (CH2)4
b ;
=
Scheme 2 Reagents and conditions: i, 1,2-dichloroethane, pyridine,
reflux
ations between 1a and 2 as well as 1d and 2 were performed
using various monomer concentrations, both in solution
(monomer conc. 0.33 ) and in the melt.1 The low molecular
weight fractions containing 3a(n) and 3d(n), were isolated and
analyzed by HPLC using previously isolated 3a(n) and 3d(n) for
quantification. The results show that even under concentrated
conditions cyclic oligomers are obtained in ca. 10 and 2% w/w
yield for 0.33  and melt, respectively (Table 4)! Since generally
‡ In the case of 4b and 4c even in the melt Mr does not exceed 5 × 103.
This indicates that condensation polymerization using either 1b or 1c as
diol mainly gives oligomers (see Experimental section).
728
J. Chem. Soc., Perkin Trans. 2, 1998

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Table 5 1H NMR conformational analysis of the HO᎐[CH()2᎐
CH()2᎐O]n᎐ units of the 9-hydroxy-1,4,7-trioxanonyl side chains of 1a
and 1da
n
1a up-up C2
1a
1d
1a up-down Ci
1
2
3
1
2
3
xg (25 ЊC, CD2Cl2)
xg (80 ЊC, C2D2Cl4)
0.94
0.92
0.92
0.88
0.91
0.85
0.94
0.91
0.94
0.88
0.92
0.85
1d up-up C2
a n = 1, 2 and 3 represent the HO᎐[CH()2᎐CH()2᎐O]n᎐ units starting
from the hydroxy functionality; xg gauche population with xg ϩ xa = 1.
With both Jab/ax and JabЈ/axЈ consistent results were obtained (cf. ref. 15
and see Experimental section).
1d up-down C2
1d up-up Cs
1d up-down Ci
Fig. 4 AM116 optimized structures of conformers of 1a and 1d,
respectively, with the 9-hydroxy-1,4,7-trioxanonyl side chains either up-
up or up-down. AM1 O᎐CH2᎐CH2᎐O torsion angles are reported in
Table 6.
Single crystal X-ray structure determination of 3a(1), 3d(1) and
6a(1)
In recent years a variety of single crystal X-ray structures of
both symmetrical and asymmetrical crownophanes have been
reported.9,10,20 The cyclic oligomers 3a(n), 3d(n) and 6a(n) are
representatives of the latter class. Suitable crystals for single
crystal X-ray structure determination of 3a(1) and 3d(1) were
obtained via vapour diffusion crystallization (solvent dichloro-
methane/non-solvent n-hexane). In the case of 6a(1) slow
evaporation of a column chromatography (eluent: acetone–n-
hexane 1:1 v/v) fraction afforded appropriate crystals (see
Experimental section). Unfortunately, suitable crystals for
single crystal X-ray structure determination of the higher
homologues with, for example, n = 2 have hitherto not been
obtained. Further work is in progress.
In Fig. 5, ORTEP representations (50% probability level) of
3a(1), 3d(1) and 6a(1) are shown. In the case of 3a(1), one
of the 1,4,7-trioxanonyl bridges possesses conformational dis-
order [ratio 0.849(9): 0.151(9)] for atoms O(25), H(241),
H(242), H(261) and H(262). With the exception of the torsion
angle O(25)᎐C(26)᎐C(27)᎐O(28) of 164.1(3)Њ (close to antiperi-
planar), all ᎐O᎐[CH()2᎐CH()2᎐O]n᎐ units in 3a(1) possess a
nearly gauche conformation with torsion angles in the range
66.7–81.1Њ. Bond lengths, valence angles and torsion angles are
in line with expectation. Inspection of the packing motif of
3a(1) reveals that its cavity is occupied by both a terephthaloyl
and a bis-substituted naphthalene unit of two symmetry related
molecules. In the solid state 3a(1) is self-complementary; it
possesses both host and guest behaviour. This is attributed to
the presence of weak non-covalent edge–face arene–arene con-
tacts21 between both terephthaloyl–naphthalene and naph-
thalene–naphthalene moieties; the centres of gravity (CG) of
the six-membered rings of the naphthyl [CG(1) and CG(2)] and
terephthaloyl [CG(3)] units of symmetry related molecules
3a(1) [distance d(CG–CG) range 4.792–5.482 Å] and their
interplanar torsion angles (range 46–88Њ) are in line with those
expected for attractive edge–face arene–arene interactions.21
The packing motif is complemented by minimalization of
unfavourable dipole–dipole interactions between neighbouring
terephthaloyl units which possess a (partial) dipole moment
(AM1;16 model compound, dimethyl terephthalate µ 2.79 D),
i.e. the inversion symmetry related terephthaloyl units of mol-
ecules 3a(1) pack face-to-face. Furthermore, weak inter- and
Fig. 3 1H NMR spectrum of 1d; comparison of the Ar᎐OCH2-
CH2᎐OCH(II)2CH(I)2᎐OCH(II)2CH(I)2OH, viz. units 1 and 2 [upper
trace, experimental (solvent C2D2Cl4, 80 ЊC) and lower trace, simulated;
see also Tables 5 and 8]
metry and up-down with Ci symmetry), for 1d four minima were
identified (up-up with either C2 or Cs symmetry and up-down
with either C2 or Ci symmetry). The calculations unequivocally
show that the HO᎐[CH()2᎐CH()2᎐O]n᎐ units possess a gauche
conformation, while the torsion angles across the C᎐O bonds
are close to antiperiplanar (Table 6). Note that our gas phase
calculations predict substantial dipole moments for the up-up
isomers of 1a (C2 symmetry, µ 2.87 D) and 1d (C2 symmetry,
µ 2.51 D and Cs symmetry, µ 3.14 D). In contrast, the dipole
moments µ of the up-down isomers of 1a and 1d possessing
Ci symmetry are zero, while 1d with C2 symmetry has a
reduced dipole moment (µ 1.78 D). Hence, to
a first
approximation the up-up isomers of 1a and 1d will be (more)
stabilized in a solvent, such as that used in our solution poly-
condensation reactions (1,2-dichloroethane; ε 10.4217) due to
favourable solute–solvent interactions.§,18 Furthermore, taking
into account the low rotational barrier across an aryl C᎐O
bond,19 we conclude that as a consequence of the preferred
gauche conformation of the HO᎐[CH()2᎐CH()2᎐O]n᎐ units
the 9-hydroxy-1,4,7-trioxanonyl side chains of the diols 1a–d
possess
a curved geometry leading to favourable pre-
orientation for intramolecular cyclization during condens-
ation polymerization.
§ To a first-order approximation the stabilization energy due to solute–
solvent interactions upon dissolution of a polar compound can be
described by E = Ϫ1/2fµ2 in which µ [1 D (Debye) = 3.33564 × 10Ϫ30
C
m] is the dipole moment of the solute and f = 2/V(ε Ϫ 1/2ε ϩ 1) with V
being the effective volume of the cavity occupied by the solute in the
particular solvent and ε the relative permittivity of the solvent.18 It is
assumed that the up-up and up-down isomers of 1a and 1d, respectively,
possess an identical effective volume V.
J. Chem. Soc., Perkin Trans. 2, 1998
729

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Table 6 AM1 O᎐CH2᎐CH2᎐O torsion angles of the HO᎐[CH()2᎐CH()2᎐O]n᎐ units n = 1, 2 and 3 of the 9-hydroxy-1,4,7-trioxanonyl side chains
of 1a and 1d
H᎐[O᎐CH()2᎐CH()2᎐O]n᎐/Њ
Compound (unita)
up-up C2 sym.
up-up Cs sym.
up-down C2 sym.
up-down Ci sym.
1a(1)
67.4
Ϫ95.1
92.0
Ϫ327.3
2.87
—
—
—
—
—
—
—
—
67.4
Ϫ95.7
91.7
Ϫ327.3
0.00
1a(2)
1a(3)
∆fH0/kcal molϪ1 b
µ/Dc
—
—
1d(1)
67.4
Ϫ96.0
93.6
Ϫ347.1
2.51
67.4
Ϫ96.3
93.6
Ϫ347.2
3.14
67.4
Ϫ96.6
93.4
Ϫ347.2
1.78
67.4
Ϫ96.6
93.4
Ϫ347.1
0.00
1d(2)
1d(3)
∆fH0/kcal molϪ1 b
µ/Dc
a n = 1, 2 and 3 represent the HO᎐[CH()2᎐CH()2᎐O]n᎐ units starting from the hydroxy functionality (see Table 5). b 1 cal = 4.184 J. c 1 D (Debye) =
3.33564 × 10Ϫ30 Cm.
Fig. 6 Packing motif of 3a(1); projection in the ab-plane (hydrogen
atoms are omitted for clarity).10 The highlighted molecules 3a(1)
occupy the cavity of a symmetry-related molecule 3a(1) depicted
shaded.
which are separated at a = 0 and a = 1 by oligo(ethyleneglycol)
chain layers (Fig. 6). An estimate of the packing ratio, i.e. the
percentage of the unit cell volume actually occupied by atoms
in the solid state, was obtained by combining the single crystal
unit cell volume, the number of crystallographically indepen-
dent molecules and the molecular volume determined with a
calculational procedure such as MOLSV.¶,22 Despite its 30 atom
perimeter, in the solid state 3a(1) packs efficiently, a packing
ratio of 71.8% is found.10
In the case of 3d(1) the bond lengths, valence angles and
torsion angles are also in line with expectation. With the excep-
tion of the O(3)᎐C(11)᎐C(12)᎐O(4) bond angle of 177.09(13)Њ
(close to antiperiplanar), all ᎐O᎐[CH()2᎐CH()2᎐O]n᎐ units
in 3d(1) possess a nearly gauche conformation with torsion
angles in the range 64.6–76.4Њ. However, exchange of the bis-
substituted naphthalene core by a phenyl core leads to con-
siderable changes in the solid-state packing motif. In contrast to
Fig. 5 ORTEP plots (50% probability) of the crownophanes 3a(1),
3a(1) attractive edge–face arene–arene interactions are absent
3d(1) and 6a(1). Atom numberings of 3a(1), 3d(1) and 6a(1) are not in
(Fig. 7). Moreover, a characteristic feature of the single crystal
agreement with IUPAC guidelines (see Experimental section).
X-ray structure of 3d(1) is the presence of one molecule of
intra-molecular C᎐H ؒ ؒ ؒ O interactions are found (Table 7).
This leads to a packing motif which consists of infinite sheets
of interpenetrating molecules 3a(1) in the bc plane at a = 1/2,
¶ In the MOLSV22 calculations the single crystal X-ray structures were
used as input data.
730
J. Chem. Soc., Perkin Trans. 2, 1998

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Table 7 Solid state inter- and intra-molecular C᎐H ؒ ؒ ؒ O interactions for 3a(1), 3d(1) and 6a(1)a
Compound
C(a)᎐H(b) ؒ ؒ ؒ O(c)
Type
d(C ؒ ؒ ؒ O)/Å
d(H ؒ ؒ ؒ O)/Å
Angle C᎐H ؒ ؒ ؒ O/Њ
3a(1)
C(23)᎐H(231) ؒ ؒ ؒ O(40)
C(27)᎐H(271) ؒ ؒ ؒ O(40)
C(3)᎐H(31) ؒ ؒ ؒ O(9)
C(11)᎐H(11) ؒ ؒ ؒ O(28)
C(11)᎐H(11B) ؒ ؒ ؒ O(2)
C(1)᎐H(1) ؒ ؒ ؒ O(1)
intra
inter
inter
inter
intra
inter
inter
inter
intra
intra
intra
intra
intra
inter
inter
inter
2.675
3.461
3.281
3.461
3.014
3.493
3.423
3.459
3.121
3.006
2.683
3.162
3.099
3.450
3.405
3.116
2.320
2.568
2.505
2.515
2.420
2.562
2.482
2.512
2.475
2.437
2.275
2.517
2.412
2.595
2.522
2.40
100.7
152.8
141.0
164.9
117.9
166.5
170.6
159.9
121.3
118.1
103.7
127.3
126.9
142.1
145.7
128.4
3d(1)
6a(1)
C(5)᎐H(5) ؒ ؒ ؒ O(6)
C(10)᎐H(10B) ؒ ؒ ؒ O(9)
C(10)᎐H(101) ؒ ؒ ؒ O(6)
C(13)᎐H(132) ؒ ؒ ؒ O(9)
C(23)᎐H(231) ؒ ؒ ؒ O(38)
C(27)᎐H(271) ؒ ؒ ؒ O(31)
C(29)᎐H(291) ؒ ؒ ؒ O(25)
C(14)᎐H(142) ؒ ؒ ؒ O(22)
C(14)᎐H(141) ؒ ؒ ؒ O(28)
C(34)᎐H(341) ؒ ؒ ؒ O(38)
a Atom numberings of 3a(1), 3d(1) and 6a(1) are not in agreement with IUPAC guidelines (see Experimental section).
Both inter- and intra-molecular CH ؒ ؒ ؒ O interactions discern-
ible in its solid-state packing motif are listed in Table 7.
Conclusions
Condensation polymerization of bis(9-hydroxy-1,4,7-trioxa-
nonyl) substituted aromatics (1a–d) with bis-acid chlorides
2, 5a and 5b, both in the melt as well as in solution using two
different monomer concentrations (0.33 and 0.033 ) gives
access to considerable amounts of cyclic oligomers, i.e.
crownophanes [melt, 2% w/w and solution (0.033 ) 30% w/w
and (0.33 ) 10% w/w]. Crownophanes with atom perimeters
up to 150 atoms were isolated. 1H NMR conformational analy-
sis of the 9-hydroxy-1,4,7-trioxanonyl side chains at 25 and
80 ЊC, viz. the temperature used for solution condensation
polymerization, reveals that all H᎐[O᎐CH()2᎐CH()2᎐O]n᎐
units are mainly present in their gauche conformation. These
experimental data are supported by semi-empirical AM1 calcu-
lations and indicate that the side chains possess a curved geom-
etry. Hence, they will be pre-oriented for intramolecular ring
closure. The results show that cyclic oligomer yields are not
influenced by the type of bis-acid chloride used. Single crystal
X-ray structure determinations of 3a(1), 3d(1) and 6a(1) show
that the solid-state packing motifs of these floppy cyclic oligo-
mers are affected by the type of diol and bis-acid constituents.
Fig. 7 Packing motif of 3d(1) with the complexed dichloromethane
moiety; view along the a-axis. Hydrogen atoms are omitted for clarity.
Fig. 8 Packing motif of 6a(1); view along the a-axis. Hydrogen atoms
are omitted for clarity. The second layer of molecules 6a(1), which is
shifted 1/2a, 1/2b, 0, is highlighted.
Experimental
dichloromethane per cyclic oligomer. It is well documented that
crown ethers containing neutral guest molecules can be stabil-
ized by either favourable dipole–dipole or hydrogen-bonding
interactions.23 A C᎐H ؒ ؒ ؒ O interaction [C(27)᎐H(27B) ؒ ؒ ؒ
O(8), C ؒ ؒ ؒ O 3.220(3) Å, H ؒ ؒ ؒ O 2.231(3) Å, C᎐H ؒ ؒ ؒ O
176.7(2)Њ] is observed between the dichloromethane moiety
and the macrocycle together with short dipole–dipole contacts
{[Cl(1)᎐H(23B) 2.841(2) Å] and [Cl(2)᎐C(20) 3.333(2) Å], Fig.
5}; additional C᎐H ؒ ؒ ؒ O interactions are listed in Table 7. For
3d(1) a packing ratio of 68.3% (MOLSV22) was determined,
also taking into account the presence of the complexed
dichloromethane.
Since for 6a(1) the incorporated bis-acid chloride 5a is ali-
phatic, edge–face interactions between the diol and bis-acid
moiety will be impaired. Again the bond lengths, valence angles
and torsion angles are within expectation. All ᎐O᎐[CH()2᎐
CH()2᎐O]n᎐ units possess a gauche conformation with torsion
angles in the range 61.1–80.5Њ. Molecules 6a(1) pack in stacks
parallel to the b-axis with the plane of the bis-substituted naph-
thalene moieties oriented perpendicular to the b-axis. The
stacks display a herringbone structure tilted with respect to the
b-axis (Fig. 8). A packing ratio of 70.4% (MOLSV22) is found.
General
All syntheses were carried out under a dry nitrogen atmosphere
unless stated otherwise. Solvents were dried using standard pro-
cedures. NMR spectra were recorded on a Bruker AC300 oper-
ating at 300 (1H NMR) and 75 MHz (13C NMR). Chemical
shifts are given relative to external TMS and all coupling con-
stants J are in Hz. All NMR measurements were performed in
CDCl3 unless stated otherwise. FTIR spectra were recorded on
a Mattson Galaxy Series FTIR 5000 Spectrometer using a dif-
fuse reflection accessory; samples were diluted in KBr. Disper-
sive IR spectra (NaCl plates or KBr pellets) were recorded on a
Perkin-Elmer 283 spectrophotometer. UV–VIS spectroscopy
was carried out on a Cary 1 in spectrophotometric grade aceto-
nitrile. HPLC was performed on a reversed phase C18 column
(either 3 or 5 µ particles, column diameter 4.6 mm and length
10 cm) using gradient elution [acetonitrile:water 1:1 (v/v) to
1:0 (v/v); elution velocity 1 ml minϪ1] and UV–detection (λ 254
nm). Gel permeation chromatography (GPC) was performed
using a mixed bed column with THF as eluent and both UV (λ
254 nm) and RI detection. Differential scanning calorimetry
(DSC, Mettler DSC 12E) was carried out at a heating rate of
5 ЊC minϪ1 and cooling rates of 1–5 ЊC minϪ1. Melt enthalpies
J. Chem. Soc., Perkin Trans. 2, 1998
731

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Table 8 Coupling constants Jab/ax and JabЈ/axЈ for the AAЈBBЈ and AAЈXXЈ patterns of the HO᎐[CH(I)2᎐CH(II)2᎐O]n᎐ units of the 9-hydroxy-1,4,7-
trioxanonyl side chains of 1a and 1d taken from simulated 1H NMR spectra at 25 (CD2Cl2) and 80 ЊC (C2D2Cl4) (see also Table 5)
Jab/ax/Hz
25 ЊC
JabЈ/ax/Hz
25 ЊC
JaaЈ/Hz
25 ЊC
JbbЈ/Hz
25 ЊC
Compound
(unit)
80 ЊC
80 ЊC
80 ЊC
80 ЊC
1a(1)a
1a(2)a
1a(3)a
1d(1)b
1d(2)b
1d(3)b
2.97
3.10
3.27
2.91
2.94
3.17
3.15
3.52
3.75
3.21
3.50
3.83
6.29
6.24
6.17
6.30
6.31
6.21
6.24
6.14
6.18
6.24
6.19
6.12
Ϫ10.41
Ϫ10.41
Ϫ10.63
Ϫ10.43
Ϫ10.94
Ϫ10.59
Ϫ10.38
Ϫ11.47
Ϫ10.22
Ϫ10.57
Ϫ10.81
Ϫ10.65
Ϫ12.01
Ϫ11.04
Ϫ11.13
Ϫ12.05
Ϫ11.01
Ϫ11.07
Ϫ11.66
Ϫ11.47
Ϫ10.85
Ϫ11.92
Ϫ10.81
Ϫ11.19
a Chemical shifts of 1a for the HO᎐[CH(I)2᎐CH(II)2᎐O]n᎐ units n = 1, 2 and 3, at 25 ЊC [unit 1 δ(I) 3.574 and δ(II) 3.659, unit 2 δ(I) 3.682 and δ(II) 3.768
and unit 3 δ(I) 3.972 and δ(II) 4.290] and at 80 ЊC [unit 1 δ(I) 3.614 and δ(II) 3.694, unit 2 δ(I) 3.709 and δ(II) 3.788 and unit 3 δ(I) 3.984 and δ(II) 4.325].
b Chemicals shifts of 1d for the HO᎐[CH(I)2᎐CH(II)2᎐O]n᎐ units n = 1, 2 and 3, at 25 ЊC [unit 1 δ(I) 3.562 and δ(II) 3.657, unit 2 δ(I) 3.648 and δ(II) 3.677
and unit 3 δ(I) 3.791 and δ(II) 4.060] and at 80 ЊC [unit 1 δ(I) 3.602 and δ(II) 3.696, unit 2 δ(I) 3.676 and δ(II) 3.704 and unit 3 δ(I) 3.812 and δ(II) 4.090].
(∆H) are reported in cal gϪ1. Cyclic voltammograms were
recorded with a Heka Potentiostat (Type: PG287; 220 V/50 Hz)
using a platinum electrode and a scan rate of 100 mV sϪ1 in dry
acetonitrile with tetrabutylammonium hexafluorophosphate
(TBAP) as electrolyte (0.1 ) and an Ag/AgNO3 reference elec-
trode. To reference all electrochemical data to SCE values the
ferrocene/ferrocenium couple was used. FABMS spectra were
measured on a JEOL JMS SX/SX 102A four-sector mass spec-
trometer operated at either 10 kV (resolution 2400 amu) or 8 kV
(resolution 3100 amu) with a JEOL MSFAB 10D FAB gun
operated with a 10 mA emission current (matrix m-nitrobenzyl
alcohol). Elemental analyses were carried out by H. Kolbe
Mikroanalytisches Laboratorium, Mülheim a.d. Ruhr,
Germany.
(1 cal = 4.184 J). Data concerning the geometry optimization,
optimized geometries and the Hessian calculations are available
upon request from one of the authors (L. W. J.).
Single crystal X-ray structures of 3a(1), 3d(1) and 6a(1)
Suitable crystals for single crystal X-ray structure deter-
mination of 3a(1)10 and 3d(1) were obtained via vapour
diffusion crystallization (solvent dichloromethane/non-solvent
n-hexane). In the case of 6a(1) slow evaporation of a column
chromatography (eluent: acetone–n-hexane 1:1 v/v) fraction
afforded appropriate crystals.
Crystal data for 3a(1).10 C30H34O10, M = 554.59, colourless
plate shaped crystal (0.05 × 0.30 × 0.62 mm), monoclinic, P21/
c, a = 13.8318(11) Å, b = 16.0285(9) Å, c = 12.5574(11) Å,
β = 107.56(1)Њ, V = 2654.3(4) Å3, Z = 4, dcalc = 1.388 g cmϪ3
,
F(000) = 1176, µ(Mo-Kα) = 1.0 cmϪ1, 7889 reflections (1.27 <
θ < 24.18Њ, ω/2θ scan; T = 150 K) were measured on an Enraf–
Nonius CAD-4T diffractometer [rotating anode, graphite
monochromated Mo-Kα radiation (λ = 0.710 73 Å)]. Data were
corrected for Lorentzian and polarization (Lp) effects and for
a linear decay (1%) of the intensity control reflections and
merged into a data set of 3928 unique reflections (Ri = 0.0540).
The structure was solved by direct methods (SHELXS-86)24
and difference Fourier techniques. One of the oxygen atoms
[O(25)] within the ring is disordered [0.151(9):0.849(9)] over
two positions. Hydrogen atoms were introduced at calculated
positions and refined riding on their carrier atoms. All non-H
atoms (except the minor disordered O atom) were refined on
F2 (SHELXL-93)25 using all 3928 unique reflections, with
anisotropic thermal parameters. Convergence was reached
at R1 = 0.0548 for 2198 reflections with I > 2.0σ(I) and 367
parameters; wR2 = 0.1189, S = 0.95 for all 3928 reflections,
w = 1/[σ2(F) ϩ (0.0473P)2]. A final difference Fourier map
1H NMR conformational analysis
1H NMR measurements on compounds 1a (15 mg) and 1d (15
mg) were performed on filtered solutions in CD2Cl2 (0.5 ml)
and C2D2Cl4 (0.5 ml) at 25 and 80 ЊC, respectively. D2O (20 µl)
was added to suppress coupling of the hydroxy proton with its
neighbouring CH2 group. At least 256 scans were accumulated
with a file size of 32 kbyte. After zero filling to 128 kbyte a
Gaussian enhancement (25 ЊC: 1a, LB Ϫ5.0 and GB 0.3 and 1d,
LB Ϫ1.0 and GB 0.3. 80 ЊC: 1a, LB Ϫ2.0 and GB 0.5 and 1d,
LB Ϫ2.0 and GB 0.5 using the WIN-NMR program14) was
applied; a resolution of 0.07 Hz per point was obtained. The
chemical shifts δ and coupling constants Jab/ax and JabЈ/axЈ for the
AAЈBBЈ/AAЈXXЈ systems of the HO᎐[CH()2᎐CH()2᎐O]n᎐
sequences in both 1a and 1d at 25 and 80 ЊC were derived from
simulated 1H NMR spectra using the GeNMR (version 3.5.1)14
computer program (Table 8). The anti (xa) and gauche (xg)
populations were calculated from the experimental coupling
constants using eqn. (1) taken from ref. 15, where for
shows no residual density outside Ϫ0.35:0.39 e ÅϪ3
.
Crystal data for 3d(1). C26H32O10ؒCH2Cl2, Mr = 589.46,
colourless block shaped crystal (0.50 × 0.50 × 0.50 mm),
monoclinic, space group P21/c, with a = 13.1880(13) Å, b =
7.9223(5) Å, c = 27.379(2) Å, β = 92.19(1)Њ, V = 2858.4(4) Å3,
Z = 4, dcalc = 1.370 g cmϪ3, F(000) = 1240, µ(Mo-Kα) = 2.8
cmϪ1; 7311 reflections (0.75 < θ < 27.50Њ; ω/2θ scan; T = 150 K)
were measured on an Enraf–Nonius CAD-4T diffractometer
[rotating anode, graphite monochromated Mo-Kα radiation
(λ = 0.710 73 Å)]. Data were corrected for a linear decay (1.2%)
of the intensity control reflections and merged into a dataset
of 6502 unique reflections. The structure was solved with
direct methods (SHELXS-86)24 and difference Fourier tech-
niques. Hydrogen atoms were introduced at calculated posi-
tions and refined riding on their carrier atoms. All non-H
atoms were refined on F2 (SHELXL-93)25 using 6486 unique
reflections, with anisotropic thermal parameters. Convergence
was reached at R1 = 0.0443 for 4813 reflections with Fo >
4.0σ(Fo) and 352 parameters; wR2 = 0.1124, S = 1.044 for
2(Jtt Ϫ Jab/ax
2Jtt Ϫ Jggx Ϫ Jggy 2Jgt Ϫ JggЈ Ϫ Jgt
)
2(Jgt Ϫ JabЈ/axЈ
)
(1)
xg =
=
X᎐CH2᎐CH2᎐Y with X = Y = O Jtt 11.91, Jgt 5.80, Jgt 12.27,
Jggx = Jggy 2.36 and JggЈ 0.44 Hz. In eqn. (1) t represents trans,
vis. anti and g represents gauche. For an explanation of Jtt, Jgt,
Jgt, Jggx, Jggy and JggЈ we refer to the original reference.15 Both
Jab/ax and JabЈ/axЈ gave consistent results (see Table 5). For chem-
ical shifts see Table 8.
Semi-empirical AM1 calculations
Calculations were performed with AM116 as implemented in
MOPAC 7.0.16 Preoptimized MMX16 geometries were further
optimized without symmetry constraints until GNORM р
0.01 using the eigenvector following (EF) routine of MOPAC
7.0. Minima were characterized by a Hessian calculation (key-
words FORCE and LARGE); no imaginary vibrations were
found. Heats of formation (∆fH0) are reported in kcal molϪ1
2
6486 reflections, w = 1/[σ2(Fo ) ϩ (0.0553 P)2 ϩ 0.73 P]. A final
732
J. Chem. Soc., Perkin Trans. 2, 1998

View Article Online
difference Fourier map shows no residual density outside
Ϫ0.38:0.34 e ÅϪ3
mesh, eluent ethyl acetate (750 ml)], after which compound 1c
.
was eluted from the column with methanol. Removal of the
solvent under reduced pressure gave 29.4 g (78.5 mmol, 78%) of
1c as a colourless oil. δH 7.12 (m, 1H), 6.50–6.47 (m, 3H), 4.10–
4.07 (m, 4H), 3.83–3.80 (m, 4H), 3.71–3.64 (m, 12H), 3.59–3.56
(m, 4H) and 2.74 (t, 2H, J 5.9); δC 159.8, 129.7, 107.1, 101.8,
72.4, 70.7, 70.3, 69.6, 67.3 and 61.6; νmax(IR, NaCl)/cmϪ1 3460
(broad), 1120, 1065.
1,4-Bis(9-hydroxy-1,4,7-trioxanonyl)benzene (1d). Hydro-
quinone (11.0 g, 0.100 mol), 2-[2-(2-chloroethoxy)ethoxy]-
ethanol (34.0 g, 0.202 mol), potassium carbonate (42 g, 0.30
mol) and DMF (250 ml) were used (cf. compound 1a for pro-
cedures). Workup after 5 days gave a pink solid which was
recrystallized from acetone (1 g/20 ml) to yield 17.9 g (47.8
mmol, 48%) of a white solid. Mp 47–49 ЊC (lit.,27 48–51 ЊC);
δH 6.84 (s, 4H), 4.09–4.06 (m, 4H), 3.84–3.81 (m, 4H), 3.73–
3.66 (m, 12H), 3.62–3.59 (m, 4H) and 2.50 (t, 2H) (see also
Table 5); δC 153.1, 115.6, 72.4, 70.8, 70.4, 69.8, 68.0 and 61.7;
νmax(FTIR, KBr)/cmϪ1 3250 (broad), 1232, 1118, 1067.
Crystal data for 6a(1). C28H38O10, Mr = 534.60, colourless
block shaped crystal (0.45 × 0.50 × 0.50 mm), monoclinic,
space group Cc, with a = 14.8295(6) Å, b = 8.2246(5) Å, c =
21.8040(15) Å, β = 92.44(1)Њ, V = 2656.9(3) Å3, Z = 4,
dcalc = 1.337 g cmϪ3, F(000) = 1144, µ(Mo-Kα) = 1.0 cmϪ1; 3644
reflections (0.94 < θ < 27.45Њ; ω scan; T = 150 K) were meas-
ured on an Enraf–Nonius CAD-4T diffractometer [rotating
anode, graphite monochromated Mo-Kα radiation (λ = 0.710 73
Å)]. Data were corrected for a linear decay (1.3%) of the inten-
sity control reflections and merged into a dataset of 3399
unique reflections. The structure was solved with direct
methods (SHELXS-86)24 and difference Fourier techniques.
Hydrogen atoms were introduced at calculated positions and
refined riding on their carrier atoms. All non-H atoms were
refined on F2 (SHELXL-93)25 using the 3399 unique reflections,
with anisotropic thermal parameters. Convergence was reached
at R1 = 0.0404 for 3091 reflections with Fo > 4.0σ(Fo) and 365
parameters; wR2 = 0.1048, S = 1.056 for 3399 reflections, w =
1,4-Bis(1-benzoyloxy-3,6,9-trioxanonyl)benzene (8). To
a
2
1/[σ2(Fo ) ϩ (0.0743 P)2 ϩ 0.176 P]. A final difference Fourier
solution of 1d (0.68 g, 1.8 mmol) in 1,2-dichloromethane (20
ml) was added successively benzoyl chloride (0.52 g, 3.7 mmol)
and freshly distilled dry pyridine (2 ml, 25 mmol). The reaction
mixture was heated at reflux temperature for 2 h, cooled to
room temperature and washed three times with water (25 ml).
The organic layer was dried on magnesium sulfate and the fil-
trate was concentrated under reduced pressure to yield 0.70 g
(1.20 mmol, 66%) of pure 8 as a waxy solid. δH 8.05 (dd, 4H,
J 1.5 and 8.3), 7.54 (m, 2H), 7.41 (m, 4H), 6.80 (s, 4H), 4.49–
4.46 (m, 4H), 4.05–4.02 (m, 4H), 3.86–3.80 (m, 8H) and 3.72 (s,
8H); δC 166.5, 153.1, 133.0, 130.1, 129.7, 128.3, 115.6, 70.8,
70.8, 69.9, 69.3, 68.1 and 64.1.
map shows no residual density outside Ϫ0.29:0.22 e ÅϪ3
.
Full crystallographic details of 3a(1),10 3d(1) and 6a(1),
excluding structure factor tables, have been deposited at the
Cambridge Crystallographic Data Centre (CCDC). For
details of the deposition scheme, see ‘Instructions for Authors’,
J. Chem. Soc., Perkin Trans. 2, available via the RSC Web pages
(http://www.rsc.org/authors). Any request to the CCDC for
this material should quote the full literature citation and the
reference number 188/112.
Syntheses
All bis(9-hydroxy-1,4,7-trioxanonyl) substituted aromatics were
Bis(1-phenoxy-3,6,9-trioxanonyl) terephthalate (9). To a solu-
tion of (9-hydroxy-1,4,7-trioxanonyl)benzene (0.70 g, 3.1
mmol) {prepared according to the procedure of 1b–d from
phenol, 2-[2-(2-ethoxy)ethoxy]ethanol and potassium carbon-
ate in DMF} in dichloromethane (20 ml) was added succes-
sively terephthaloyl dichloride (0.31 g, 1.53 mmol) and freshly
distilled dry pyridine (2 ml, 25 mmol). The reaction mixture was
heated at reflux temperature for 2 h, cooled to room temper-
ature and washed three times with water (25 ml) containing
NaCl. The organic layer was dried on magnesium sulfate and
the filtrate was concentrated under reduced pressure to yield
0.74 g (1.27 mmol, 83%) of pure 9 as a waxy solid. δH 8.10
(s, 4H), 7.29–7.24 (m, 4H), 6.96–6.87 (m, 6H), 4.52–4.48 (m,
4H), 4.12–4.09 (m, 4H), 3.87–3.84 (m, 8H) and 3.76 (s, 8H);
δC 165.7, 158.6, 133.8, 129.6, 129.4, 120.8, 114.5, 70.8, 70.7,
69.8, 69.1, 67.2 and 64.5.
synthesized using modified literature procedures.26–28
1,5-Bis(9-hydroxy-1,4,7-trioxanonyl)naphthalene (1a). To a
solution of 1,5-dihydroxynaphthalene (22.0 g, 0.136 mol) and
2-[2-(2-chloroethoxy)ethoxy]ethanol (48.0 g, 0.284 mol) in
DMF (500 ml) potassium carbonate (57 g, 0.41 mol) was added
under vigorous stirring. After stirring the suspension at 50 ЊC
for 3 days, the solvent was removed under reduced pressure.
The dark viscous residue was triturated with methylene chloride
after which the precipitated salts were removed by filtration.
The filtrate was concentrated under reduced pressure to yield
crude 1a, which was recrystallized twice from acetone (1 g/20
ml) to yield 34 g (80.2 mmol, 59%) of an off-white powder. Mp
68–69 ЊC (lit.,26 67–68 ЊC); δH 7.87 (d, 2H, J 8.4), 7.35 (dd, 2H,
J 8.4, 7.6), 6.84 (d, 2H, J 7.6), 4.32–4.28 (m, 4H), 4.01–3.98 (m,
4H), 3.82–3.79 (m, 4H), 3.73–3.70 (m, 8H), 3.62–3.60 (m, 4H)
and 2.45 (br s, 2H) (see also Table 5); δC 154.3, 126.8, 125.1,
114.6, 105.7, 72.5, 71.0, 70.5, 69.8, 67.9 and 61.8; νmax(FTIR,
KBr)/cmϪ1 3430 (broad), 1271, 1122, 1081.
1,2-Bis(9-hydroxy-1,4,7-trioxanonyl)benzene (1b). Catechol
(11.0 g, 0.100 mol), 2-[2-(2-chloroethoxy)ethoxy]ethanol (34.0
g, 0.202 mol), potassium carbonate (42 g, 0.3 mol) and DMF
(250 ml) were used (cf. compound 1a for procedures). Workup
after 3 days gave a brown oil as the crude product. After flash
chromatography on silica gel [230–400 mesh, eluent ethyl
acetate (750 ml)] to remove impurities compound 1b was eluted
from the column with methanol. Removal of the solvent under
reduced pressure gave 12.8 g (34.2 mmol, 34%) of 1b as a light
yellow oil. δH 6.87 (s, 4H), 4.15–4.11 (m, 4H), 3.84–3.80 (m,
4H), 3.71–3.63 (m, 12H), 3.61–3.56 (m, 4H) and 3.34 (br s,
2H); δC 148.6, 121.5, 114.6, 72.4, 70.5, 70.1, 69.5, 68.6 and 61.3;
νmax(IR, NaCl)/cmϪ1 3330 (broad), 1255, 1112, 1065.
General procedure for solution condensation polymerization.
The appropriate diol (10.0 mmol) was dissolved in either 300 ml
(monomer conc. 0.033 ) or 30 ml (monomer conc. 0.33 )
of 1,2-dichloroethane. After the solution was deareated and
placed under a dry nitrogen atmosphere the appropriate bis-
acid chloride (10.0 mmol) was added. Subsequently, pyridine
(5 ml) was added dropwise to the reaction mixture at room
temperature. After heating at reflux temperature for 3 h, the
reaction mixture was cooled to room temperature, concentrated
under reduced pressure to one-third of its volume and poured
into a five-fold excess of vigorously stirred methanol. The
methanol solution was decanted from the oily precipitate and
concentrated under reduced pressure to yield a light brown oil
containing the cyclic oligomers. The cyclic oligomers were isol-
ated using preparative column chromatography [silica; eluent
acetone–n-hexane (1:1 v/v)]. The purity of all cyclic oligomers
was established using HPLC.
1,3-Bis(9-hydroxy-1,4,7-trioxanonyl)benzene (1c). Resorcinol
(11.0 g, 0.100 mol), 2-[2-(2-chloroethoxy)ethoxy]ethanol (34.0
g, 0.202 mol), potassium carbonate (42 g, 0.30 mol) and DMF
(250 ml) were used (cf. compound 1a for procedures). Workup
after 8 days gave the crude product as a dark red oil. Impurities
were removed by flash chromatography on silica gel [230–400
General procedure for melt condensation polymerization.1
Equimolar amounts (5.0 mmol) of the diol and the bis-acid
chloride were mixed in a Schlenk flask (25 ml) under a nitrogen
atmosphere and subsequently heated at 100 ЊC under magnetic
stirring. To remove the evolving HCl gas the Schlenk flask was
J. Chem. Soc., Perkin Trans. 2, 1998
733

View Article Online
continuously flushed with a stream of nitrogen gas. After 20–30
min at 100 ЊC stirring became impaired due to an increase in
viscosity of the reaction mixture. Therefore, the reaction mix-
ture was gradually heated from 100–180 ЊC in 20 min in order
to force the reaction to completion. After cooling to room
temperature the reaction mixture was dissolved in THF (30 ml)
and the polymer was precipitated in a five-fold excess of vigor-
ously stirred methanol. The methanol solution was decanted
from the oily precipitate and concentrated under reduced pres-
sure yielding a light brown oil containing the series of cyclic
oligomers.
10H, J 7.6), 4.48–4.45 (m, 20H), 4.25–4.22 (m, 20H), 3.97–3.94
(m, 20H) and 3.85–3.71 (m, 60H); δC 165.7, 154.3, 133.8, 129.6,
126.7, 125.0, 114.6, 105.7, 71.0, 70.8, 69.8, 69.1, 67.9 and 64.5;
m/z (FABMS) 2771 ([MϩH]ϩ).
3,6,9,12,19,22,25,28-Octaoxatricyclo[28.2.2.013,18]tetratria-
conta-1(32),13(18),14,16,30,33-hexaene-2,29-dione
[3b(1)].—
1.12 g (3.0 mmol, 30%) of a white solid. Mp 81–82 ЊC; DSC
80.7 ЊC, ∆H 23.0 cal gϪ1; δH 8.07 (s, 4H), 6.94–6.85 (m, 4H),
4.50–4.47 (m, 4H), 4.13–4.09 (m, 4H), 3.85–3.79 (m, 8H) and
3.72 (s, 8H); δC 165.6, 149.1, 133.9, 129.6, 121.8, 115.9, 71.0, 70.8,
69.9, 69.0 and 64.7; νmax(FTIR, KBr)/cmϪ1 1737, 1282, 1140;
m/z (FABMS) 505 ([MϩH]ϩ); (Calc. for C26H32O10: C, 61.90; H,
6.39; O, 31.71. Found: C, 61.78; H, 6.42; O, 31.66%).
3,6,9,12,19,22,25,28,35,38,41,44,51,54,57,60-Hexadecaoxa-
pentacyclo[60.2.2.230,33.013,18.045,50]octahexaconta-1(64),13,15,17,
30,32,45(50),46,48,62,65,67-dodecaene-2,29,34,61-tetraone
[3b(2)].—0.19 g (0.25 mmol, 5%) of a white solid. Mp 113–
115 ЊC; DSC 111.1 ЊC, ∆H 18.0 cal gϪ1; δH 8.05 (s, 8H), 6.87 (s,
8H), 4.48–4.45 (m, 8H), 4.13–4.10 (m, 8H), 3.85–3.81 (m, 16H)
and 3.76–3.67 (m, 16H); δC 165.6, 149.0, 133.8, 129.5, 121.6,
114.8, 70.8, 70.7, 69.8, 69.1, 68.9 and 64.5; νmax(FTIR, KBr)/
cmϪ1 1730, 1271, 1128; m/z (FABMS) 1009 ([MϩH]ϩ); (Calc.
for C52H64O20: C, 61.90; H, 6.39; O, 31.71. Found: C, 61.30; H,
6.34%).
3,6,9,12,23,26,29,32-Octaoxatetracyclo[32.2.2.013,18.017,22]-
octatriaconta-1(36),13,15,17(22),18,20,34,37-octaene-2,33-
dione [3a(1)].—0.57 g (1.03 mmol, 10.3%) of a white solid. Mp
117–118 ЊC; DSC 116.7 ЊC, ∆H 26.8 cal gϪ1; δH 7.79 (d, 2H, J
8.6), 7.64 (s, 4H), 7.23 (dd, 2H, J 8.6 and 7.6), 6.71 (d, 2H, J
7.6), 4.47–4.44 (m, 4H), 4.21–4.18 (m, 4H), 4.00–3.98 (m, 4H),
3.88–3.80 (m, 8H) and 3.77–3.75 (m, 4H); δC 165.7, 154.2,
133.3, 129.1, 126.7, 124.9, 114.6, 105.6, 71.1, 70.9, 69.7, 69.1,
68.0 and 64.2; νmax(FTIR, KBr)/cmϪ1 1721, 1271, 1097; m/z
(FABMS) 555 ([MϩH]ϩ); (Calc. for C30H34O10: C, 64.97; H,
6.18; O, 28.85. Found: C, 64.86; H, 6.19%).
3,6,9,12,23,26,29,32,39,42,45,48,59,62,65,68-Hexadecaoxa-
heptacyclo[68.2.2.234,37.013,18.017,22.049,54.053,58]hexaheptaconta-
1(72),13,15,17,19,21,34,36,49,51,53,55,57,70,73,75-hexadeca-
ene-2,33,38,69-tetraone [3a(2)].—0.18 g (0.16 mmol, 3.2%) of
a white solid. Mp 125–126 ЊC; DSC 125.0 ЊC, ∆H 17.1 cal
3,6,9,12,19,22,25,28,35,38,41,44,51,54,57,60,67,70,73,76,83,
86,89,92-Tetracosaoxaheptacyclo[92.2.2.230,33.262,65.013,18.045,50
0
.
77,82]dohecta-1(96),13,15,17,30,32,45,47,49,62,64,77,79,81,94,
g
Ϫ1; δH 7.99 (s, 8H), 7.81 (d, 4H, J 8.4), 7.27 (dd, 4H, J 8.4 and
96,97,99,101-octadecaene-2,29,34,61,66,93-hexaone [3b(3)].—
0.04 g (0.03 mmol, 1%) of a colourless oil. δH 8.05 (s, 12H), 6.87
(s, 12H), 4.48–4.45 (m, 12H), 4.13–4.10 (m, 12H), 3.85–3.80
(m, 24H) and 3.75–3.67 (m, 24H); δC 165.6, 148.9, 133.8, 129.5,
121.6, 114.8, 70.8, 70.7, 69.8, 69.0, 68.8 and 64.4; m/z (FABMS)
1513 ([MϩH]ϩ).
7.6), 6.76 (d, 4H, J 7.6), 4.48–4.45 (m, 8H), 4.23–4.20 (m, 8H),
3.97–3.94 (m, 8H) and 3.84–3.71 (m, 24H); δC 165.7, 154.3,
133.8, 129.5, 126.7, 125.0, 114.5, 105.6, 71.0, 70.9, 69.8, 69.1,
67.9 and 64.5; νmax(FTIR, KBr)/cmϪ1 1726, 1272, 1099; m/z
(FABMS) 1109 ([MϩH]ϩ); (Calc. for C60H68O20: C, 64.97; H,
6.18; O, 28.85. Found: C, 64.92; H, 6.21%).
3,6,9,12,18,21,24,27-Octaoxatricyclo[27.2.2.113,17]tetratria-
3,6,9,12,23,26,29,32,39,42,45,48,59,62,65,68,75,78,81,84,95,
conta-1(31),13,15,17(34),29,32-hexaene-2,28-dione
[3c(1)].—
98,101,104-Tetracosaoxadecacyclo[104.2.2.234,37.270,73.013,18
.
0.79 g (2.1 mmol, 21%) of a white solid. Mp 98–99 ЊC; DSC
98.6 ЊC, ∆H 23.8 cal gϪ1; δH 8.06 (s, 4H), 7.12 (t, 1H, J 8.2), 6.48
(dd, 2H, J 8.2 and 2.3), 6.37 (t, 1H, J 2.3), 4.52–4.49 (m, 4H),
4.02–3.99 (m, 4H), 3.86–3.83 (m, 8H) and 3.77–3.72 (m, 8H); δC
165.7, 159.8, 133.8, 129.7, 129.6, 107.1, 101.1, 71.1, 70.7, 69.7,
69.1, 67.4 and 64.6; νmax(FTIR, KBr)/cmϪ1 1739, 1726, 1270,
1119; m/z (FABMS) 505 ([MϩH]ϩ); (Calc. for C26H32O10: C,
61.90; H, 6.39; O, 31.71. Found: C, 62.03; H, 6.38; O,
31.64%).
3,6,9,12,18,21,24,27,34,37,40,43,49,52,55,58-Hexadecaoxa-
pentacyclo[58.2.2.229,32.113,17.144,48]octahexaconta-1(62),13,15,
17(68),29,31,45,47,60,63,65,67-dodecaene-2,28,33,59-tetraone
[3c(2)].—0.11 g (0.15 mmol, 3%) of a white solid. Mp 73–74 ЊC;
DSC 74.2 ЊC, ∆H 11.1 cal gϪ1; δH 8.07 (s, 8H), 7.12 (m, 2H),
6.48–6.45 (m, 6H), 4.50–4.47 (m, 8H), 4.07–4.04 (m, 8H),
3.86–3.80 (m, 16H) and 3.72 (s, 16H); δC 165.7, 159.9, 133.9,
129.8, 129.6, 107.1, 101.8, 70.8, 69.8, 69.1, 67.4 and 64.5;
νmax(FTIR, KBr)/cmϪ1 1733, 1266, 1095; m/z (FABMS) 1009
([MϩH]ϩ); (Calc. for C52H64O20: C, 61.90; H, 6.39; O, 31.71.
Found: C, 61.98; H, 6.43%).
017,22.049,54.053,58.085,90.089,94]tetradecaundeca-1(108),13,15,17,19,
21,34,36,49,51,53,55,57,70,72,85,87,89,91,93,106,109,111,113-
tetracosaene-2,33,38,69,74,105-hexaone [3a(3)].—0.069 g (0.04
mmol, 1.2%) of a colourless oil. δH 8.03 (s, 12H), 7.82 (d,
6H, J 8.5), 7.29 (dd, 6H, J 8.5 and 7.6), 6.77 (d, 6H, J 7.6),
4.48–4.45 (m, 12H), 4.24–4.21 (m, 12H), 3.97–3.93 (m, 12H)
and 3.85–3.71 (m, 36H); δC 165.6, 154.2, 133.8, 129.5, 126.7,
125.0, 114.5, 105.6, 70.9, 70.8, 69.8, 69.1, 67.8 and 64.5; m/z
(FABMS) 1663 ([MϩH]ϩ); (Calc. for C90H102O30: C, 64.97; H,
6.18; O, 28.85. Found: C, 64.89; H, 6.22%).
3,6,9,12,23,26,29,32,39,42,45,48,59,62,65,68,75,78,81,84,95,
98,101,104,111,114,117,120,131,134,137,140-Dotriacontaoxa-
tridecacyclo[140.2.2.234,37.270,73.2106,109.013,18.017,22.049,54.053,58
.
085,90.089,94.0121,126.0125,130]dopentacontahecta-1(144),13,15,17,19,
21,34,36,49,51,53,55,57,70,72,85,87,89,91,93,106,108,121,123,
125,127,129,142,144,145,147,149,151-dotriacontaene-2,33,38,
69,74,105,110,141-octaone [3a(4)].—0.068 g (0.03 mmol, 1.2%)
of a light yellow oil. δH 8.04 (s, 16H), 7.82 (d, 8H, J 8.5),
7.29 (dd, 8H, J 8.5 and 7.6), 6.79 (d, 8H, J 7.6), 4.48–4.45
(m, 16H), 4.23–4.21 (m, 16H), 3.99–3.94 (m, 16H) and
3.85–3.72 (m, 48H); δC 165.7, 154.3, 133.8, 129.6, 126.7,
125.0, 114.6, 105.7, 71.0, 70.8, 69.8, 69.1, 67.9 and 64.5; m/z
(FABMS) 2217 ([MϩH]ϩ); (Calc. for C120H136O40: C, 64.97; H,
6.18; O, 28.85. Found: C, 64.94; H, 6.24%).
2,5,8,11,18,21,24,27-Octaoxatricyclo[26.2.2.213,16]tetratria-
conta-1(30),13,15,28,31,33-hexaene-12,17-dione [3d(1)].—0.86 g
(2.3 mmol, 23%) of a white solid. Mp 91–92 ЊC; DSC 91.6 ЊC,
∆H 18.3 cal gϪ1; δH 8.03 (s, 4H), 6.71 (s, 4H), 4.53–4.49 (m, 4H),
3.99–3.96 (m, 4H), 3.88–3.85 (m, 4H), 3.81–3.78 (m, 4H) and
3.72 (s, 8H); δC 165.7, 153.1, 133.9, 129.5, 115.8, 70.9, 70.8, 69.7,
69.0, 68.4 and 64.3; νmax(FTIR, KBr)/cmϪ1 1717, 1279, 1116;
m/z (FABMS) 505 ([MϩH]ϩ); (Calc. for C26H32O10: C, 61.90;
H, 6.39; O, 31.71. Found: C, 61.86; H, 6.46%).
2,5,8,11,18,21,24,27,32,35,38,41,48,51,54,57-Hexadecaoxa-
pentacyclo[56.2.2.213,16.228.31.243,46]octahexaconta-1(60),13,15,
28,30,43,49,58,61,63,65,67-dodecaene-12,17,42,47-tetraone
[3d(2)].—0.15 g (0.20 mmol, 4%) of a white solid. Mp 113–
115 ЊC; DSC 115.3 ЊC, ∆H 23.6 cal gϪ1; δH 8.07 (s, 8H), 6.80 (s,
8H), 4.50–4.47 (m, 8H), 4.02–3.99 (m, 8H), 3.85–3.78 (m, 16H)
3,6,9,12,23,26,29,32,39,42,45,48,59,62,68,75,78,81,84,95,98,
101,104,111,114,117,120,131,134,137,140,147,150,153,156,167,
170,173,176-Tetracontaoxahexadecacyclo[176.2.2.234,37.270,73
.
2106,109.2142,145.013,18.017,22.049,54.053,58.085,90.089,94.0121,126.0125,130
.
0157,162.0161,166]nonacontahecta-1(180),13,15,17,19,21,34,36,49,
51,53,55,57,70,72,85,87,89,91,93,106,108,121,123,125,127,129,
142,144,157,159,161,163,165,178,181,183,185,187,189-tetra-
contaene-2,33,38,69,74,105,110,141,146,177-decaone [3a(5)].—
0.008 g (0.003 mmol, 0.1%) of a light yellow oil. δH 8.05 (s,
20H), 7.82 (d, 10H, J 8.5), 7.29 (dd, 10H, J 8.5 and 7.6), 6.77 (d,
734
J. Chem. Soc., Perkin Trans. 2, 1998

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and 3.71 (s, 16H); δH 165.7, 153.0, 133.9, 129.6, 115.5, 70.8 (2×),
69.9, 69.1, 68.0 and 64.5; νmax(FTIR, KBr)/cmϪ1 1721, 1279,
1114; m/z (FABMS) 1009 ([MϩH]ϩ); (Calc. for C52H64O20: C,
61.90; H, 6.39; O, 31.71. Found: C, 61.78; H, 6.34%).
Polymer 4b.—Precipitation afforded 1.36 g (54%) of a brown
viscous oil. δH([2H6]DMSO) 8.03 (m, 4H), 6.89–6.83 (m, 4H),
4.38 (m, 4H), 4.40 (m, 4H), 3.73–3.68 (m, 8H), 3.58 (s, 8H);
δC([2H6]DMSO) 165.4, 148.3, 133.5, 129.4, 121.1, 114.3, 69.9
(2×), 69.0, 68.2 (2×) and 64.4; GPC Mr 5 × 103, D 1.48; DSC Tg
Ϫ14.2 ЊC (midpoint).
2,5,8,11,18,21,24,27,32,35,38,41,48,51,54,57,62,65,68,71,78,
81,84,87-Tetracosaoxaheptacyclo[86.2.2.213,16.228,31.243,46.258,61
2
.
73,76]dohecta-1(90),13,15,28,30,43,45,58,60,73,75,88,91,93,95,
Polymer 4c.—Precipitation of the crude product in methanol
gave 1.31 g (52%) of a viscous brown oil. δH([2H6]DMSO) 8.04
(s, 4H), 7.10 (m, 1H), 6.50–6.44 (m, 3H), 4.41 (m, 4H), 3.93 (m,
4H), 3.76–3.69 (m, 8H) and 3.60 (s, 8H); δC([2H6]DMSO) 165.7,
159.9, 133.9, 129.6, 107.1, 101.8, 70.9, 70.7, 69.8, 69.2, 67.4 and
64.5; GPC Mr 5 × 103, D 1.50; DSC Tg Ϫ17.8 ЊC (midpoint).
Polymer 4d.—Precipitation of the crude product afforded
1.46 g (58%) of a light brown viscous oil. δH([2H6]DMSO) 8.04
(s, 4H), 6.77 (s, 4H), 4.42–4.40 (m, 4H), 3.94–3.91 (m, 4H),
3.76–3.74 (m, 4H), 3.68–3.65 (m, 4H) and 3.58 (s, 8H);
δC([2H6]DMSO) 164.8, 152.4, 133.4, 129.3, 115.1, 69.7, 68.9,
68.1, 67.3 and 64.3; GPC Mr 2.6 × 104, D 1.89; DSC Tg Ϫ5.7 ЊC
(midpoint).
97,99,101-octadecaene-12,17,42,47,72,77-hexaone
[3d(3)].—
0.04 g (0.025 mmol, 1%) of a colourless oil. δH 8.07 (s, 12H),
6.78 (s, 12H), 4.48–4.45 (m, 12H), 4.02–3.99 (m, 12H), 3.84–
3.78 (m, 24H) and 3.70 (s, 24H); δC 165.6, 153.0, 133.9, 129.5,
115.5, 70.7 (2×), 69.8, 69.1, 68.0 and 64.5; m/z (FABMS) 1513
([MϩH]ϩ).
6,9,12,15,22,25,28,31-Octaoxatricyclo[30.4.0.05,36]hexatria-
conta-1,3,5(36),32,34-pentaene-16,21-dione [6a(1)].—0.86
g
(1.61 mmol, 16.4%) of colourless crystals. Mp 96–98 ЊC; DSC
100.7 ЊC, ∆H 33.7 cal gϪ1; δH 7.87 (d, 2H, J 8.5), 7.34 (dd, 2H,
J 8.5 and 7.6), 6.87 (d, 2H, J 7.6), 4.33–4.30 (m, 4H), 4.13–4.10
(m, 4H), 4.01–3.98 (m, 4H), 3.79–3.77 (m, 4H), 3.68–3.64 (m,
8H), 2.01–1.94 (m, 4H) and 1.32–1.27 (m, 4H); δC 173.2, 154.3,
126.9, 125.1, 114.6, 105.9, 71.0, 70.8, 69.8, 69.0, 68.2, 63.3, 33.5
and 24.0; νmax(FTIR, KBr)/cmϪ1 1746, 1730, 1265, 1159; m/z
(FABMS) 535 ([MϩH]ϩ); (Calc. for C28H38O10: C, 62.91; H,
7.17; O, 29.92. Found: C, 62.74; H, 7.15%).
6,9,12,15,22,25,28,31,42,45,48,51,58,61,64,67-Hexadecaoxa-
pentacyclo[66.4.0.05,72.032,37.036,41]henheptaconta-1,3,5(72),32,34,
36(41),37,39,68,70-decaene-16,21,52,57-tetraone [6a(2)].—0.26
g (0.24 mmol, 4.9%) of a light brown solid. Mp 52–53 ЊC; DSC
52.5 ЊC, ∆H 18.1 cal gϪ1; δH 7.85 (d, 4H, J 8.5), 7.32 (dd, 4H,
J 8.5 and 7.6), 6.82 (d, 4H, J 7.6), 4.30–4.25 (m, 8H), 4.23–4.18
(m, 8H), 4.00–3.94 (m, 8H), 3.81–3.74 (m, 8H), 3.73–3.64 (m,
16H), 2.30–2.25 (m, 8H), 1.62–1.57 (m, 8H); δC 173.2, 154.3,
126.8, 125.1, 114.6, 105.7, 70.9, 70.7, 69.8, 69.2, 67.9, 63.5, 33.7,
24.2; νmax(FTIR, KBr)/cmϪ1 1738, 1269, 1165; m/z (FABMS)
1069 ([MϩH]ϩ); (Calc. for C56H76O20: C, 62.91; H, 7.17; O,
29.92. Found: C, 62.81; H, 7.19%).
Acknowledgements
Experimental contributions by R. H. G. Neilen and M. J. J.
Mulder are gratefully acknowledged. This work was supported
in part (A. L. S., N. V. and W. J. J. S.) by the Netherlands
Foundation of Chemical Research (SON) with financial aid
from the Netherlands Organization for Scientific Research
(NWO).
References
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3,6,9,12,23,26,29,32-Octaoxatetracyclo[32.3.1.013,18.017,22]-
octatriaconta-1(38),13,15,17(22),18,20,34,36-octaene-2,33-
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7.86 (dd, 2H, J 7.8 and 1.5), 7.71 (d, 2H, J 8.5), 7.16 (dd, 2H,
J 8.5 and 7.6), 6.94 (t, 1H, J 7.8), 6.69 (d, 2H, J 7.6), 4.36–4.32
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8H) and 3.74–3.71 (m, 4H); δC 165.5, 154.2, 133.3, 130.7, 130.1,
128.1, 126.7, 124.8, 114.5, 105.8, 71.1, 71.0, 69.8, 69.0, 68.0 and
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3,6,9,12,23,26,29,32,40,43,46,49,60,63,66,69-Hexadecaoxa-
heptacyclo[69.3.1.134,38.013,18.017,22.050,55.054,59]hexaheptaconta-
1(75),13,15,17(22),18,20,34,36,38(76),50(55),51,53,56,58,71,73-
hexadecaene-2,33,39,70-tetraone [6b(2)].—0.27 g (0.24 mmol,
4.8%) of a white solid. Mp 120–121 ЊC; DSC 120.5 ЊC, ∆H 22.8
cal gϪ1; δH 8.66 (t, 2H, J 1.5), 8.15 (dd, 4H, J 7.8 and 1.7), 7.79
(d, 4H, J 8.5), 7.38 (t, 2H, J 7.8), 7.25 (dd, 4H, J 8.5 and 7.6),
6.73 (d, 4H, J 7.6), 4.46–4.43 (m, 8H), 4.22–4.19 (m, 8H), 3.96–
3.93 (m, 8H), 3.84–3.76 (m, 16H) and 3.73–3.70 (m, 8H); δC
165.7, 154.3, 133.9, 130.8, 130.5, 128.5, 126.7, 125.0, 114.6,
105.7, 71.0, 70.8, 69.8, 69.2, 67.9 and 64.5; νmax(FTIR, KBr)/
cmϪ1 1732, 1253, 1082; m/z (FABMS) 1109 ([MϩH]ϩ); (Calc.
for C60H68O20: C, 64.97; H, 6.18; O, 28.85. Found: C, 64.90; H,
6.25%).
Polymer Fraction. Polymer 4a.—Precipitation of the crude
product in methanol gave 1.80 g (65%) of a light brown viscous
oil. δH([2H6]DMSO) 7.97 (s, 4H), 6.67–7.65 (m, 2H), 7.31–
7.25 (m, 2H), 6.86 (m, 2H), 4.37 (m, 4H), 4.14 (m, 4H), 3.82–
3.74 (m, 8H) and 3.62 (s, 8H); δC([2H6]DMSO) 164.8, 153.7,
133.4, 129.3, 125.9, 125.2, 113.7, 105.8, 70.0, 69.9, 68.9, 68.2,
67.6 and 64.4; GPC Mr 1.8 × 104, D 1.80; DSC Tg 9.3 ЊC
(midpoint).
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Paper 7/01920C
Received 19th March 1997
Accepted 29th October 1997
736
J. Chem. Soc., Perkin Trans. 2, 1998