The CA.M lattice revisited. Gel formation from a linear bis-isocyanuric acid and 2-amino-4,6-bis-(4-tert-butylphenylamino)-1,3,5-triazine

Article abstract of DOI:10.1016/j.tet.2004.03.059

Five bis(isocyanuric) acid dimers have been prepared and characterised. The introduction of flexible alkyl chains was necessary to aid solubility. On mixing with N,N-bis(4-tert-butyphenyl)melamine in THF followed by slow evaporation, a viscous gel can form which is interpreted as evidence for the assembly of an infinite 2-D hydrogen bonded network.

Full text of DOI:10.1016/j.tet.2004.03.059

Tetrahedron 60 (2004) 6385–6394
The CA.M lattice revisited. Gel formation from a linear
bis-isocyanuric acid and
2-amino-4,6-bis-(4-tert-butylphenylamino)-1,3,5-triazine
a
a
b
M. John Plater,a James P. Sinclair, Stuart Aiken, Thomas Gelbrich
,
*
and Michael B. Hursthouseb
aDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, UK
bDepartment of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
Received 2 January 2004; revised 27 February 2004; accepted 18 March 2004
Available online 28 May 2004
Abstract—Five bis(isocyanuric) acid dimers have been prepared and characterised. The introduction of flexible alkyl chains was necessary
to aid solubility. On mixing with N,N-bis(4-tert-butyphenyl)melamine in THF followed by slow evaporation, a viscous gel can form which is
interpreted as evidence for the assembly of an infinite 2-D hydrogen bonded network.
q 2004 Published by Elsevier Ltd.
1. Introduction
trans conformation resulting in an essentially planar
H3C(CH2)3C(CH2)3CH3 unit. The mean plane of this unit
is approximately perpendicular to that of the ring. In the
third independent molecule of 1, both alkyl chains are in
end-gauche conformation
The cyanuric acid–melamine lattice (CA.M)1,2 has been a
source of inspiration3,4 for the study of hydrogen bonded
aggregates. By mixing melamine derivatives and iso-
cyanuric acid or dialkylbarbituric acid derivatives,
hydrogen bonding is restricted to give discrete aggregates
which can be studied in solution and in some cases
crystallised.4,5 The crystallisation of diethylbarbituric acid
with N,N-bis(4-substituted phenyl)melamines gives either
linear tape, crinkled tape or a rosette motif depending upon
the substituents on the aryl rings.5 If 4-tert-butyl substituted
aryl rings are used as substituents then the rosette motif
(Fig. 1) crystallises. The steric bulk of the tert-butyl groups
disfavours linear or crinkled tapes. This structure prepared
by us is very similar to the original rosette crystallised by the
group of Whitesides.5 The motif is not quite planar in
contrast to the cyclic motif observed in the crystal structure
of the CA.M lattice2 suggesting that the deviation from
planarity is a consequence of crystal packing forces since
there are no steric interactions between the substituents.
Our approach to preparing new networked materials was to
attempt to ‘expand’ the CA.M lattice by introducing a linear
spacer between pairs of cyanuric acids. The anticipated 2-D
hydrogen bonded network is shown in Figure 2. It would
consist of sheets with hexagonal cavities which are lined by
six N,N-bis(4-tert-butyphenyl) groups of the melamines.
This example would represent a macrocyclic architecture
formed by supramolecular chemistry that can bind to a
multiple number of six exchangeable melamine derivatives
with convergent functionality that forms a cavity.
2. Results and discussion
Initially we prepared the linear bis-isocyanuric acids 11 and
15 (Schemes 1 and 2). Biuret 3 was nitrated to give
nitrobiuret 45 then reacted with 4-iodoaniline or 2-chloro-4-
iodoaniline to give compounds 5 and 6, respectively.
Cyclisation was achieved by heating with NaOEt in EtOH
with (EtO)2CvO.3 To our surprise, compound 7 underwent
Sonogashira coupling with trimethylsilylacetylene despite
possessing the acidic functionality of the isocyanuric acid
group. Building block 10 was formed by removing the
trimethylsilyl group with KOH/MeOH. Coupling of com-
pound 7 with 10 gave the first isocyanuric acid dimer 11.
In the structure of components 1 and 2, rosette motifs form
¯ ¯
sheets that extend in {111} planes. These sheets are packed
in parallel fashion. Adjacent sheets within the stack are
related by inversion symmetry. In two of the three
independent molecules of 1, the alkyl chains adopt an all-
Keywords: 2-Amino-4,6-bis-(4-tert-butylphenylamino)-1,3,5-triazine;
Cyanuric acid; Hydrogen bonding; Rosette motif.
*
Corresponding author. Tel.: þ44-1224-272927; fax: þ44-1224-272921;
e-mail address: m.j.plater@abdn.ac.uk
0040–4020/$ - see front matter q 2004 Published by Elsevier Ltd.
doi:10.1016/j.tet.2004.03.059

6386
M. J. Plater et al. / Tetrahedron 60 (2004) 6385–6394
Figure 1. Crystal structure of a rosette formed from components 1 and 2.
Dimer 15 was prepared by palladium catalysed coupling
of diethnylbenzene 146 with 4-iodophenylisocyanuric
acid 7.
Given that CHCl3 is a more desirable solvent for these
studies a further series of dimers 29–31 were prepared
which contained solubilising alkyl chains in the centre
(Scheme 3). The synthesis of diethnyl precursors 26–287,8
follows standard methods and indeed all of the inter-
mediates have been previously reported.7–11 Palladium
coupling of compounds 27–28 with 4-iodophenyliso-
cyanuric acid 7 gave the extended dimers 29 and 31,
respectively. Palladium coupling of precursor 26 was less
successful. The purification was aided by the flexible alkyl
chains, which enhance solubility and give the compounds
surfactant-like properties. Excess iodophenylisocyanuric
acid is easily removed by extraction of the crude solid
with aqeous NaOH. The sodium salt of this is water soluble
while the sodium salt, mono or bis, of the dimer is still
insoluble in acid or base. The dimer is then treated with acid
to ensure reprotonation. The dimers are much more soluble
than the unsubstituted dimers 11 and 15 and can be
dissolved in THF. The molecular ion in the MALDI mass
spectrum showed the same peak intensity pattern as that
calculated theoretically which aided characterisation. How-
ever, although good proton and carbon spectra were
obtained, the MALDI spectra showed evidence of oligomers
of compounds 26–28 coupled terminally with isocyanuric
Both dimers 11 and 15 are poorly soluble but were of
interest because they might have packed well in a crystal
lattice. They dissolved in DMSO allowing good proton and
carbon spectra to be obtained but were too involatile to
provide mass spectral molecular ions. Ideally for rosette
formation, solubility in CHCl3 is desired because in this
relatively non-polar solvent strong hydrogen bonding
between components can occur. In contrast, in polar
solvents such as DMSO and THF, hydrogen bonding
between components is much weaker and rosette aggregates
break up. However, we anticipated that for a concentrated
solution in a polar solvent, 2-D network formation may still
occur because of cooperative stabilisation owing to the
infinite network. A 2-D network should be more stable than
1-D chains which should be more stable than discrete
aggregates. However, all attempts made to form a network
from dimers 11 and 15 with N,N-bis(4-tert-butylphenyl)-
melamine in THF and DMSO were unsuccessful. In all
cases, slow evaporation of solvent gave a powder which
could not be characterised.

M. J. Plater et al. / Tetrahedron 60 (2004) 6385–6394
6387
Figure 2. Drawing of the proposed 2-D structural motif formed between compounds 29 and 2.
acids. For this reason an alternative route to prepare 29 was
used which involved coupling N-(4-ethynylphenyl)iso-
cyanuric acid 10 with 1,4-didecyloxy-2,5-diiodobenzene
21. This route avoids the formation of similar polymeric
oligomers and gives a product of greater purity (Scheme 4).
Unfortunately dimers 29 and 31, which possesses a longer
side chain, are not soluble in CHCl3. To enhance solubility
in CHCl3, dimer 30 was prepared which has a chlorine
substituent adjacent to each isocyanuric acid. This should
cause some molecular twisting and reduce the symmetry
and so enhance solubility. Compound 30 has a slight
solubility in CHCl3 because a suspension of 30 in CHCl3
turns yellow in colour although the solubility is not enough
to obtain NMR data in CHCl3.
2-D network formation was studied in concentrated THF

6388
M. J. Plater et al. / Tetrahedron 60 (2004) 6385–6394
Scheme 1. Reagents and conditions: (i) HNO3/H2SO4 (40%); (ii) 4-iodoaniline or 2-chloro-4-iodoaniline/H2O/K; (iii) diethyl carbonate/Na/EtOH/K; (iv) 7/
TMS–C2H/(PPh3)2PdCl2/Cul/Et3N/RT/THF/1–3 days; (v) KOH/MeOH/rt/15; (vi) 7/(PPh3)2PdCl2/CuI/Et3N.
Scheme 2. Reagents and conditions: (i) TMS–C2H/(PPh3)2PPCl2/CuI/Et3N/rt/THF; (ii) KOH/MeOH/rt/15 min; (iii) 7/(PPh3)2PdCl2/CuI/Et3N/rt.
solution. An interesting result was obtained from mixing
THF solutions of dimer 29 with N,N-bis(4-tert-butyphenyl)-
melamine 1. A solution of the dimer in THF was mixed with
a solution of compound 1 and allowed to slowly evaporate
in a sample vial. In one case this was done over a few
months in an NMR tube. As the solvent slowly evaporates
the solutions become thick and viscous with gel like
properties. A skin could form on the surface which
redissolved on mixing and heating. The gel would not
pour from the vessel. If desolvation was continued the
sample eventually reverted to a dry flaky powder. In contrast
if the dimer 29 alone or the melamine 1 alone is slowly
concentrated in THF no gel like phase is observed but a
powder eventually forms. Also concentration of a solution
of the dimer with N,N-bis(phenyl)melamine does not give a
viscous gel like phase but forms a powder as the
components precipitate from solution. The viscous gel
phase is interesting evidence for the formation of extended
2-D sheets depicted in diagram 2 which are still in solution.
On slow solvent evaporation an extended network of
hydrogen bonds could form, stabilised by the infinite
network. A concentrated solution is necessary because of
the polar solvent THF which would normally break up
rosettes. N,N-bis(4-tert-butyphenyl)melamine 1 favours
rosette formation over other structural motifs, so the motif
depicted in Figure 2 is our proposal. Dimers 30 and 31 did
not form gels with melamine 1 from THF showing that the
gel formation is sensitive to the dimer structure. The
precipitated material may still consist of extended networks
but it is difficult to characterise. Evidently a dimer soluble in
CHCl3 is desired because the network formation could be
studied in a less concentrated solution and may be easier to
crystallise. Furthermore the methodology to produce
compounds with this type of spacer structure that are
soluble in water is known12 so isocyanuric acid dimers with
these spacers might allow assembly in water to be studied.
In conclusion, linear bis(isocyanuric) acid dimers have been
prepared and characterised. On mixing one with N,N-bis(4-
tert-butyphenyl)melamine in THF followed by slow
evaporation, a gel forms which is interpreted as evidence
for the assembly of an infinite and soluble 2-D hydrogen
bonded network The network is predicted to have hexagonal
like cavities each of which binds six exchangeable
melamines on the inside with the tert-butylphenyl groups
pointing inwards forming a cavity.13

M. J. Plater et al. / Tetrahedron 60 (2004) 6385–6394
6389
Scheme 3. Reagents and conditions: (i) hexylbromide, decylbromide or hexadecylbromide/K2CO3/acetone/K; (ii) I2/KIO3/H2SO4/HOAc/H2O; (iii) TMS–
C2H/(PPh3)2PdCl2/CuI/Et3N/rt/THF; (iv) KOH/MeOH/THF/2 h; (v) 7 or 8/(PPh3)2PdCl2/CuI/Et3N/K.
Scheme 4. Reagents and conditions: (i) (PPh3)2PdCl2/Cul/Et3N/D.
1
3. Experimental
as determined by H NMR spectra. Low-resolution mass
spectra were obtained using electrospray ionization on a
Finnigan Navigator Mass Spectrometer and accurate mass
at the University of Wales. Swansea using fast atom
bombardment methods and MALDI. For dimers 29, 30 and
31 the theoretical peak pattern for the MALDI spectrum is
listed. Aldrich, Lancaster Synthesis, Avocado and BDH
supplied starting materials. Et3N was dried by distillation
from CaH2, EtOH was dried by distillation from mag-
nesium, toluene from sodium, and THF from potassium
using benzophenone as the indicator. All dried solvents
were transferred from the stills to the reaction vessels using
oven dried glass syringes under nitrogen. Reactions
requiring anhydrous conditions were carried out in three-
necked r.b. flasks, which were flame dried while under
vacuum and then purged three times with either argon or
nitrogen.
3.1. General
Melting points were carried out using a Kofler hot-stage
microscope and are uncorrected. Butterworth Laboratories,
using a PE.2400 CHN analyser, conducted elemental
analysis. Ultraviolet spectra were recorded on a Perkin–
Elmer Lambda 15 UV–VIS spectrometer using DCM, THF
and DMSO as the solvents. Infrared spectra were recorded
on an ATI Mattson FTIR spectrometer. H and 13C NMR
1
spectra were obtained at 250 and 62.9 MHz, respectively, on
a Brucker AC 250 spectrometer and at 400 and 100.5 MHz,
respectively on a Varian 400 spectrometer. Chemical shifts
(d) are given in ppm relative to the residual solvent.
Coupling constants, (J) are given in Hz. All compounds
were prepared to a high standard of purity, greater than 95%

6390
M. J. Plater et al. / Tetrahedron 60 (2004) 6385–6394
3.1.1. 1-Nitrobiuret 4.3 Biuret 3 (51.5 g, 0.5 mol) was
added in 1 g portions to a mixture of sulphuric acid
(125 mL, ,97%) and nitric acid (30 mL, ,69%), chilled in
an ice bath, over 30 min. After the mixture had been stirred
for 2 h, all the solid had dissolved, and the solution was
poured onto ice (1 kg). The ice was allowed to melt and the
precipitate was filtered. The precipitate was suspended in
water (1 L), chilled in an ice bath, and sodium hydroxide
(400 mL, 1 M) was added to bring the pH to ,8.5. The
solution was filtered cold and the product precipitated with
concentrated HCl to pH,2, filtered, washed with water and
dried under vacuum to give the title compound (30 g, 40%)
as a white powder; dH (250 MHz; DMSO-d6) 4.95 (2H, s, br,
NH2), 7.07–7.39 (1H, d, NH) and 9.42 (1H, s); dC
(62.9 MHz; DMSO-d6)148.8 and 153.2; m/z (ES) 147.0
(MþþNa, 100%).
DMSO-d6) 94.9, 131.6, 134.2, 137.7, 148.9 and 149.6; m/z
331.1 (Mþ, 100%).
3.1.5. N-(2-Chloro-4-iodophenyl)isocyanuric acid 8.
0.54 g, 34%. White powder, mp .260 8C (from water).
n
max(KBr)/cm21 3420br, 3208br, 3082br, 2847w, 1751s,
1704s, 1574m, 1476s, 1419s, 1408s, 1375m, 830m, 789m,
761m, 603m, 555m and 533m; dH (250 MHz; DMSO-d6)
7.33 (1H, d, J¼8.2 Hz, Ar), 7.81 (1H, d, J¼7.9 Hz, Ar), 8.05
(1H, s, Ar) and 11.9 (2H, br s, NH); dC (62.9 MHz; DMSO-
d6) 96.3, 131.6, 133.1, 133.6, 137.1, 137.2, 148.7 and 148.8;
m/z (ES2) 364.3 (M2H, 100%); m/z (ES2) 363.8987
(M2H, 100% C9H5ClIN3O3 requires 363.8991).
3.1.6. N-(4-Trimethylsilylethynylphenyl)isocyanuric
acid 9. A mixture of isocyanuric acid 7 (0.4 g, 1 mmol),
trimethylsilylacetylene (0.23 g, 2 mmol), Pd(PPh3)2Cl2
(20 mg, 28 mmol), CuI (4 mg, 21 mmol) in THF (25 mL)
and Et3N (4 mL) under an argon atmosphere was stirred, at
rt, for 8 h. The solvent was removed under reduced pressure
and the residue, dissolved in DCM, filtered through silica to
elute impurities followed by elution with ethyl acetate. The
solvent was removed under reduced pressure and the residue
washed with light petroleum to give the title compound
(0.25 g, 68%) as an off white solid, mp .250 8C. (Found: C,
55.0; H, 5.0; N, 12.9. C11H10N3O3 requires C, 55.8; H, 5.0;
N, 13.9%); nmax (KBr)/cm21 2969vs, 2939vs 2759vs,
2678vs, 2474m, 1463vs, 1413s, 1359m, 1162s, 1064w,
1029vs, 842w and 798m; dH (250 MHz; DMSO-d6) 0.24
(9H, s, Si–Me), 7.34 (2H, d, J¼8.2 Hz), 7.53 (2H, d,
J¼8.2 Hz) and 11.58 (2H, bs); dC (62.9 MHz; DMSO-d6)
20.1, 95.1, 104.5, 122.3, 129.7, 132.0, 134.7, 148.9 and
149.6; m/z (ES) 301 (MþþNa, 100%); m/z (ES) 319.1224
(MþNH4, 100% C14H15N3SiO3 requires 319.1221).
3.1.2. 1-(4-Iodophenyl)biuret 5. General procedure. A
mixture of 1-nitrobiuret 4 (4.78 g, 32 mmol) and 4-iodo-
aniline (5.14 g, 25 mmol) in water (50 mL) was heated at
reflux for 2 h. The precipitated product was filtered hot,
washed with water and MeOH to give the title compound
(5.4 g, 71%) as a grey powder, mp .230 8C. (Found: C,
31.7; H, 2.6; N, 13.8. C8H8IN3O2 requires C, 31.5; H, 2.6;
N, 13.8%); nmax (KBr)/cm21 3386vs, 3311m, 3241m,
3207m, 3151m, 3050m, 2979m, 2923m, 1729vs, 1689vs,
1581vs, 1533vs, 1508vs, 1481s, 1429vs, 1384vs, 1299vs,
1213vs, 1118s, 1078m, 991w, 879w, 815s, 732m, 682w and
651; dH (250 MHz; DMSO-d6) 6.90 (2H, vbs, NH2), 7.29
(2H, d, J¼8.6 Hz), 7.61 (2H, d, J¼8.6 Hz), 8.93 (1H, s) and
10.05 (1H, s); dC (62.9 MHz; DMSO-d6) 86.3, 121.3, 137.5,
138.1, 151.9 and 155.5; m/z 305.9741 (MþþH. C8H9IN3O2
requires 305.9739).
3.1.3. 1-(2-Chloro-4-iodophenyl)biuret 6. 3.1 g, 77%.
Grey powder, mp .230 8C (decomp. from water)
3.1.7. N-(4-Ethynylphenyl)isocyanuric acid 10. Iso-
cyanuric acid 9 (0.71 g, 2.3 mmol) was suspended in
ethanol (40 mL). Aqueous sodium hydroxide (40 mL,
1 M) was added and the solution stirred. After 1 h the
solvent was reduced to 50 mL and concentrated HCl was
added to adjust the pH to 7. The precipitate was filtered and
the residue was washed with water to give the title
compound (0.32 g, 59%) as off white solid, mp .200 8C
(from water). (Found: C, 57.1; H, 3.2; N, 17.3. C11H10N3O3
requires C, 57.6; H, 3.1; N, 18.3%); nmax (KBr)/cm21
3484w, 3413m, 3303m, 3226vs, 3201vs, 3097vs, 3054vs,
2875s, 2420m, 2358vs, 2329vs, 1984m, 1810vs, 1675vs,
1612m, 1502vs, 1380vs, 1267w, 1211m, 1095m, 908w,
840m, 809w, 754vs, 725vs, 632vs, 547s, 474w and 428s; dH
(250 MHz; DMSO-d6) 4.27 (1H, s, CCH), 7.36 (2H, d,
J¼8.3 Hz), 7.56 (2H, d, J¼8.3 Hz), and 11.59 (2H, s); dC
(62.9 MHz; DMSO-d6) 81.6, 82.9, 122.0, 129.7, 132.2,
134.7, 148.9 and 149.6; m/z 228.1 (Mþ2H, 100%) m/z
247.0827 (MþþNH4, 100% C11H7N3O3 requires
247.0827).
n
max(KBr)/cm21 3441m, 3256m, 3194m, 1704s, 1621m,
1590s, 1578s, 1505s, 1370m, 1351m, 1297m, 1272m,
1257s, 1232s and 818m; dH (250 MHz; [2H6]DMSO) 6.9
(2H, br s, NH2), 7.64 (1H, d, J¼8.9 Hz, Ar), 7.83 (1H, s,
Ar), 8.03 (1H, d, J¼8.6 Hz, Ar), 9.34 (1H, s, NH) and 10.9
(1H, s, NH); dC(62.9 MHz; DMSO-d6) 61.2, 86.3, 122.6,
123.1 135.2, 136.5, 151.6 and 155.8; m/z (EI) 357.0
(MþþNH4, 100%) and 340.0 (MþþH, 31), m/z (EI)
339.9351 (MþþH, 100. C8H7ClIN3O2 requires 339.9344).
3.1.4. N-(4-Iodophenyl)isocyanuric acid 7. General
procedure. Sodium ethoxide was prepared by dissolving
sodium (0.49 g, 21 mmol) in dry ethanol (60 mL) under an
argon atmosphere. Biuret 5 (1.83 g, 6 mmol) and diethyl
carbonate (1.42 g, 12 mmol) were added to this solution.
The mixture was heated at reflux for 24 h, allowed to cool
and toluene was added. The sodium salt was filtered, washed
with toluene and dried. The solid was dissolved in water,
filtered and dilute HCl was added and the precipitate was
filtered, washed with water and dried under vacuum to give
the title compound (1.1 g, 55%) as a white powder, mp
.200 8C. (Found: C, 32.1; H, 1.8; N, 12.3. C9H6IN3O3
requires C, 32.6; H, 1.8; N, 12.7%); nmax (KBr)/cm21
3212s, 3064s, 2831m, 1799vs, 1762vs, 1693vs, 1479vs,
1402vs, 1211m, 1114w, 1068w, 1010w, 881w, 823m and
744vs; dH (250 MHz; DMSO-d6) 7.16 (2H, d, J¼8.5 Hz),
7.82 (2H, d, J¼8.5 Hz), and 11.58 (2H, bs); dC (62.9 MHz;
3.1.8. Bis-1,2-ethynyl-(4-phenylisocyanuric acid) 11. A
stirred solution of 1-(4-ethynylphenyl)isocyanuric acid 10
(250 mg, 1.09 mmol),1-(4-iodophenyl)isocyanuric acid 7
(360 g, 1.09 mmol) and CuI and (PPh3)2PdCl2 in catalytic
amounts dissolved in degassed anhydrous THF (40 mL) was
treated with Et3N (3 mL). The mixture was refluxed for
24 h, then another aliquot of 1-(p-iodophenyl)isocyanuric

M. J. Plater et al. / Tetrahedron 60 (2004) 6385–6394
6391
acid (200 g) was added. The organic solvent was removed
under reduced pressure before the remaining solid was
partially dissolved up in 10% sodium hydroxide (40 mL).
The insoluble material was collected by filtration then
stirred as a suspension in THF (60 mL) and water (60 mL)
whilst conc. hydrochloric acid (15 mL) was added drop-
wise. The acidic mixture was allowed to stir for 2 h,
followed by removal of the organic solvent under reduced
pressure, addition of water (30 mL), filtration and a final
wash with fresh water (20 mL) to give the title compound
(180 mg, 38%) as a brown powder, mp .250 8C (from
tetrahydrofuran) nmax(KBr)/cm21 3454br, 3216m, 3070m,
2833m, 1791s, 1762s, 1522s, 1444s, 1408s, 1214w, 840m,
756m, 744m, 734m, 721m, and 549m; dH(250 MHz;
DMSO-d6) 7.41 (4H, d, J¼7.6 Hz, Ar), 7.65 (4H, d,
J¼7.3 Hz, Ar) and 11.64 (4H, s, NH); dC(250 MHz;
DMSO-d6) 89.4, 122.3, 129.8, 131.9, 134.6, 148.9 and
149.8.
(60 mL) whilst conc. hydrochloric acid (15 mL) was added
dropwise. The acidic mixture was allowed to stir for 2 h,
followed by removal of the organic solvent under reduced
pressure, addition of water (30 mL), filtration and a final
wash with fresh water (20 mL) to give the title compound
(393 mg, 47%) as a pale yellow powder, mp .250 8C
(from water). (Found C: 62.6, H, 3.6. C28H16N6O6 requires
C, 63.2; H, 3.0%); lmax(DMSO)/nm 325 (log 1 4.6);
n
max(KBr)/cm21 3783w, 3258s, 3098s, 3063s, 1796s,
1754vs, 1692vs, 1488vs, 1460s, 1418s, 1390m, 838w and
787vs; dH(250 MHz; DMSO-d6) 7.41 (4H, d, J¼8.2 Hz,
Ar), 7.63 (4H, s, Ar), 7.66 (4H, d, J¼8.6 Hz, Ar) and 11.64
(4H, s, NH); dC(62.9 MHz; DMSO-d6) 89.6, 90.8, 122.2,
122.4, 129.7, 131.8, 132.0, 134.7, 148.9 and 149.7.
3.1.12. 1,4-Dihexyloxybenzene 17.9 General procedure. A
solution of hydroquinone (18.2 g, 0.110 mol), bromohexane
(40.4 g, 0.242 mol) and K2CO3 (15.2 g) in acetone
(400 mL), was refluxed under a nitrogen atmosphere for 3
days. Toluene (300 mL) was added, then the solution was
filtered hot, and the filtrate was concentrated to a brown
solid which was redissolved in DCM. Washed twice with
dilute sodium dithionate and dilute sodium hydroxide,
dried over MgSO4, and reduced to 10 mL appearing as an
orange solution. This was then passed through a silca plug
and concentrated to give the title compound (25.1 g, 82%),
as a crystalline solid, mp 44–45 8C (from acetone).
3.1.9. 1,4-Bis(trimethylsilylethynyl)benzene 13.6 Tri-
methylsilylacetylene (3.57 g, 0.036 mol) was added to a
stirred solution of 1,4-diiodobenzene (4.0 g, 0.012 mol),
CuI and (PPh3)2PdCl2 in catalytic amounts dissolved in
degassed anhydrous Et3N (60 mL). The reaction mixture
was refluxed for 8 h under a nitrogen atmosphere then the
solvent was removed under reduced pressure. The residue
was taken up in DCM and filtered through a silica plug.
Afterwards the solvent was removed under reduced
pressure. The residue was dissolved in (1:1) methanol/ethyl-
acetate (40 mL) and cooled in an ice water bath for 3 h. The
product readily crystallised and was collected by filtration to
yield the title compound (1.75 g, 54%) as clear crystalline
material, mp 121–123 8C (from methanol/ethylacetate 1:1)
(lit. 122 8C) dH(250 MHz; CDCl3) 0.24 (18H, s, Si(CH3)3)
and 7.38 (4H, s, Ar); dC(62.9 MHz; CDCl3) 20.06, 96.3,
104.6, 123.2 and 131.8.
n
max(KBr)/cm21 2924vs, 2871vs, 1509s, 1476m, 1396m,
1286m, 1237vs, 1115m, 1033s, 996m, 828s, 773m and
730w; dH(250 MHz; CDCl3) 0.90 (6H, t, J¼6.5 Hz, Me),
1.34 (12H, m, CH2), 1.75 (4H, m, CH2), 3.89 (4H, t,
J¼6.6 Hz, OCH2) and 6.81 (4H, s, Ph); dC(62.9 MHz;
CDCl3) 14.1, 22.7, 25.8, 29.4, 31.7, 68.7, 115.4 and 153.2;
m/z (EI) 278.2245 (Mþ, C18H30O2 requires 278.2240), m/z
(ES) 279.1 (MþþNa, 100%).
3.1.13. 1,4-Didecyloxybenzene 18.10 18.3 g, 69%. White
powder, mp 67–68 8C (from ethanol/dichloromethane 1:1);
3.1.10. 1,4-Diethynylbenzene 14.6 To a stirred solution
of 1,4-bis(trimethylsilylethynyl)benzene 13 (1.5 g,
5.55 mmol) in DCM (25 mL) and methanol (25 mL), was
added dropwise potassium hydroxide (1 M, 10 mL). The
mixture was left to stir for 3 h, then the organic solvent was
removed under reduced pressure. Water (30 mL) was added
and the mixture was extracted with ether (3£30 mL), dried
with MgSO4 and treated with decolourising charcoal. The
solvent was removed under reduced pressure to yield the
title compound (0.48 g, 70%) as a white solid, mp 94–95 8C
(from diethyl ether) (lit 95–96 8C) dH(250 MHz; CDCl3)
3.2 (2H, s, acetylenic H) and 7.45 (4H, s, Ar); dC(62.9 MHz;
CDCl3) 79.1, 83.1, 122.6 and 132.0.
n
max(KBr)/cm21 2961s, 2936s, 2857s, 1509s, 1476m,
1396m, 1380w, 1287m, 1244vs, 1115m, 1032s, 828s,
772m and 659m; dH(250 MHz; CDCl3) 0.88 (6H, t,
J¼6.6 Hz, Me), 1.26 (28H, m, CH2), 1.77 (4H, m,
OCH2CH2), 3.89 (4H, t, J¼6.5 Hz, OCH2) and 6.81 (4H,
s, Ph); dC(62.9 MHz; CDCl3)14.2, 22.7, 22.9, 29.2, 29.3,
29.4, 29.6, 31.9, 68.7, 115.4 and 153.2 (one resonance is
missing); m/z (EI) 290.4 (Mþ, 100%).
3.1.14. 1,4-Dihexadecyloxybenzene 19.7 15.2 g, 60%.
White solid, mp 82–84 8C (from ethanol); nmax(KBr)/cm21
;
dH(250 MHz; CDCl3) 0.84 (6H, br t, Me), 1.25 (52H, m,
C13H23), 1.73 (4H, m, OCH2CH2), 3.88 (4H, t, J¼6.7 Hz,
OCH2) and 6.8 (4H, s, Ph); dC(62.9 MHz; CDCl3) 14.2,
22.7, 26.1, 29.4, 29.6, 29.7, 32.0, 69.7, 115.4 and 153.2 (8
missing resonances).
3.1.11. 1,4-Phenylethynyl-(4-phenylisocyanuric acid) 15.
A stirred solution of 1,4-diethynylbenzene 14 (200 mg,
3.17 mmol), 1-(4-iodophenyl)isocyanuric acid 7 (2.1 g,
12.7 mmol) and CuI and (PPh3)2PdCl2 in catalytic amounts
dissolved in degassed anhydrous THF (60 mL) was treated
with Et3N (5 mL). The mixture was refluxed for 12 h, then
the organic solvent was removed under reduced pressure,
redissolved in a large volume of THF and filtred through a
silica plug. After concentration, the remaining solid was
partially dissolved up in 10% sodium hydroxide (40 mL).
The insoluble material was collected by vacuum filtration
then stirred as a suspension in THF (60 mL) and water
3.1.15. 1,4-Dihexyloxy-2,5-diiodobenzene 20.11 General
procedure. A solution of 1,4-dihexyloxy 17 benzene (1.0 g,
3.6 mmol), KIO3 (0.92 g, 1.8 mmol) and iodine (0.23 g,
4.3 mmol) in acetic acid (50 mL), sulphuric acid (1 mL) and
water (5 mL), was refluxed for 4 h. To the reaction was
added iodine (0.2 g, 1.58 mmol) and KIO3 (0.5 g,
2.34 mmol), and reflux continued for another 7 h. A solution
of sodium thionite (2.0 g in water 20 mL) was added and a

6392
M. J. Plater et al. / Tetrahedron 60 (2004) 6385–6394
colour change from orange to yellow was observed. The
precipate was filtered to give the title compound (0.58 g,
30%) as yellow/white crystalline blocks mp 58–59 8C (from
ethanol) nmax(KBr)/cm21 3493m, 3424m, 2943s, 2851m,
1451s, 1347m, 1209vs, 1061m, 993m and 937m;
dH(250 MHz; CDCl3) 0.90 (6H, t, J¼6.9 Hz, Me), 1.33
(12H, m, CH2), 1.79 (4H, m, CH2), 3.92 (4H, t, J¼6.4 Hz,
CH2) and 7.16 (2H, s, Ph); dC(62.9 MHz; CDCl3) 14.1, 22.6,
25.8, 29.2, 31.5, 70.4, 86.3, 122.8 and 152.9; m/z (ES) 530.1
(Mþ, 100%).
(18H, s, SiMe3), 0.89 (6H, m, Me), 1.23 (24H, m, C6H12),
1.45 (4H, m, CH2), 1.75 (4H, m, CH2), 3.93 (4H, t,
J¼6.3 Hz, OCH2) and 6.85 (2H, s, Ph); dC(62.9 MHz;
CDCl3) 20.04, 8.8, 14.1, 22.7, 26.0, 29.3, 29.4, 29.6, 29.65,
31.9, 46.5, 69.4, 100.1, 101.0, 113.9, 117.1 and 154.0; m/z
(EI) 583.5 (MþþH, 100%).
3.1.20. 1,4-Bis(trimethylsilylethynyl)-2,5-dihexa-
decyloxybenzene 25.7 0.87 g, 47%. Off-white solid, mp
65–66 8C (from dichloromethane) dH(250 MHz; CDCl3)
0.24 (18H, s, Si(CH3)3), 0.87 (6H, br t, CH3), 1.25 (52H, m,
C14H28), 3.93 (4H, t, J¼6.3 Hz, OCH2) and 6.88 (2H, s, Ar);
dC(62.9 MHz; CDCl3) 0.0, 14.2, 22.7, 26.1, 29.4, 29.5, 29.7,
32.0, 69.5, 100.1, 101.1, 113.9, 117.2 and 154.0 (8
resonances are overlapping).
3.1.16. 1,4-Didecyloxy-2,5-diiodobenzene 21.8 2.7 g, 41%.
White powder, mp 62–63 8C (from ethanol). (Found: C,
48.2; H, 6.7. C26H44I2O2 requires C, 48.6; H, 6.9%);
n
max(KBr)/cm21 2940s, 2925vs, 2846s, 1487m, 1447m,
1388m, 1354m, 1264w, 1216s, 1071m, 1053m and 847m;
dH(250 MHz; CDCl3) 0.87 (6H, t, J¼6.6 Hz, Me), 1.27
(28H, m, CH2)1.8 (4H, m, OCH2CH2), 3.9 (4H, t, J¼6.4 Hz,
OCH2) and 7.2 (2H, s, Ph); dC(62.9 MHz; CDCl3) 14.2,
22.7, 26.1, 29.2, 29.3, 29.4, 29.6, 32.0, 70.4, 86.4, 122.8 and
152.9 (one missing resonance); m/z (EI) 660 (MþþNH4,
100%) and 642.3 (Mþ, 75).
3.1.21. 1,4-Diethynyl-2,5-dihexyloxybenzene 26.7
General procedure. A stirred solution of 1,4-bis-trimethyl-
silylethynyl-2,5-dihexyloxybenzene
23
(250 mg,
0.53 mmol) in anhydrous THF (20 mL) and methanol
(20 mL) was treated with (4 mL) 20% KOH, and continued
to stir for another 3 h. The reaction mixture was reduced to
the aqueous slurry, where more water (30 mL) was added
and extracted with dichloromethane (3£50 mL). The
combined extracts were dried and evaporated under reduced
pressure to give the title compound (100 mg, 61%) as a
yellow crystalline solid, mp 69–71 8C (from methanol)
3.1.17. 1,4-Dihexadecyloxy-2,5-diiodobenzene 22.7
6.07 g, 84%. White powder, mp 77–79 8C (from ethanol/
dichloromethane 1:1) dH(250 MHz; CDCl3) 0.87 (6H, br t,
CH3), 1.25 (52H, m, CH2), 1.78 (4H, br t, OCH2CH2), 3.91
(4H, br t, OCH2) and 7.16 (2H, s, Ar); dC(62.9 MHz;
CDCl3) 14.2, 22.7, 26.1, 29.2, 29.3, 29.4, 29.6, 29.7, 29.9,
32.0, 70.4, 86.3, 122.8 and 152.9 (6 resonances are
overlapping).
l
max(CH2Cl2)/nm 233 (log 1 4.0) and 271 (4.3); nmax(KBr)/
cm21 3266s, 2959s, 2939s, 2917s, 2852s, 1499s, 1468s,
1385s, 1218vs, 1197s, 1029s, 997m, 862m and 652m;
dH(250 MHz; CDCl3) 0.89 (6H, m, 2£CH3), 1.33 (12H, m,
2£C3H6), 1.76 (4H, m, 2£OCH2CH2), 3.35 (2H, s, 2£C2H),
3.96 (4H, t, J¼6.4 Hz, 2£OCH2) and 6.94 (2H, s, Ph);
dC(62.9 MHz; CDCl3) 14.1, 22.6, 25.6, 28.1, 31.5, 69.6,
79.2, 83.0, 113.3, 117.7 and 154.8; m/z (ES) 470.2 (Mþ,
87%), 431.3 (35), 359.2 (53), 293.1 (40) and 279.1 (100).
3.1.18. 1,4-Bis(trimethylsilylethynyl)-2,5-dihexyloxy-
benzene 23.7 General procedure. A stirred solution of
1,4-dihexyloxy-2,5-diiodobenzene 20 (1.24 g, 0.92 mmol)
trimethylsilylacetylene (0.92 g, 9.35 mmol), (PPh3)2PdCl2
(60 mg, 0.086 mmol) and of CuI (40 mg, 0.21 mmol) in
anhydrous THF (20 mL) was treated with Et3N (2 mL,
0.014 mol) under nitrogen at room temperature. The
reaction was stirred for 24 h after which the solvent was
removed in vacuo. The solid was dissolved in CH2Cl2
(10 mL), filtered through a 4 cm silica plug and eluted with
dichloromethane to give the title compound (0.48 g, 86%)
as a grey crystalline solid, mp 91–92 8C (from methanol)
3.1.22. 1,4-Diethynyl-2,5-didecyloxybenzene 27.8 1.06 g,
86%. Yellow powder, mp 70–72 8C (from methanol)
lmax(CH2Cl2)/nm 232 (log 1 4.0), 262 (4.3), 271 (4.5),
337 (3.9); nmax(KBr)/cm21 3285s, 2927vs, 2850s, 1502m,
1471m, 1384s, 1270m, 1215s, 1048m, 1028m, 992m, 867m,
667m and 646m; dH(250 MHz; CDCl3) 0.86 (6H, m, Me),
1.25 (28H, m, C7H14), 1.77 (4H, m, OCH2CH2), 3.3 (2H, s,
CH), 3.95 (4H, t, J¼6.6 Hz, OCH2) and 6.93 (2H, s, Ph);
dC(62.9 MHz; CDCl3) 14.2, 22.7, 25.9, 29.1, 29.4, 29.6,
31.9, 69.6, 79.8, 82.4, 113.2, 117.7 and 154.0 (2 missing
resonances); m/z (ES) 456.3836 (MþþNH4) C30H46O2
requires 456.3836); m/z (EI) 456.6 (MþþNH4, 83%) and
439.5 (MþþH, 100).
l
max(CH2Cl2)/nm 237 (log 1 5.2), 270 (5.3), 285 (5.7) and
344 (5.0); nmax(KBr)/cm21 2960s, 2939s, 2868m, 2156m,
1500m, 1469m, 1408m, 1386s, 1249s, 1225s, 1203s, 1032s,
894s, 867vs, 758m, 730m, 693m, 664m and 625m;
dH(250 MHz; CDCl3) 0.24 (18H, s, SiMe3), 0.89 (6H, br t,
Me), 1.3 (8H, m, C2H4), 1.55 (4H, m, CH2), 1.75 (4H, m,
CH2), 3.93 (4H, t, J¼6.3 Hz, OCH2) and 6.88 (2H, s, Ph);
dC(62.9 MHz; CDCl3) 20.03, 14.0, 22.7, 25.7, 29.3, 31.6,
69.4, 100.1, 101.1, 113.9, 117.2 and 154.0; m/z (ES)
471.3104 (MþþH, 100%) C28H47Si2O2 requires 471.3109),
m/z (ES) 470.2 (M, 87%), 431.3 (35), 359.2 (53), 293.1 (40)
and 279.1 (100).
3.1.23. 1,4-Diethynyl-2,5-dihexadecyloxybenzene 28.7
0.51 g, 64%. Yellow solid, mp 87–88 8C (lit. 89–90 8C)
(from methanol) dH(250 MHz; CDCl3) 0.87 (6H, br t, CH3),
1.25 (52H, m, C13H26), 1.75 (4H, br t, OCH2CH2), 3.32 (2H,
s, CCH), 3.95 (4H, t, J¼6.3 Hz, OCH2) and 6.94 (2H, s, Ar);
dC(62.9 MHz; CDCl3) 14.1, 22.7, 25.9, 29.2, 29.4, 29.6,
29.7, 32.0, 69.7, 79.8, 82.4, 113.3, 117.7 and 154.0 (7
resonances are missing).
3.1.19. 1,4-Bis(trimethylsilylethynyl)-2,5-didecyloxy-
benzene 24.8 2.17 g, 65%. Grey crystalline solid, mp 72–
73 8C (from methanol) lmax(CH2Cl2)/nm 237 (log 1 4.2),
270 (4.2), 285 (4.5) and 345 (3.9); nmax(KBr)/cm21 2943s,
2851m, 2157m, 1500m, 1471m, 1388m, 1225s, 1204m,
1032m, 893s, 855s and 759m; dH(250 MHz; CDCl3) 0.24
3.1.24. 1,4-Bis[4-(isocyanuric acid)phenylethynyl)-2,5-
didecyloxybenzene 29. General procedure Method 1. To
a stirred solution of N-(4-iodophenyl)isocyanuric acid 7

M. J. Plater et al. / Tetrahedron 60 (2004) 6385–6394
6393
(0.5 g, 1.14 mmol), 1,4-diethynyl-2,5-dihexyloxybenzene
26 (1.13 g, 3.42 mmol), copper(I) iodide (40 mg,
0.21 mmol), bis(triphenylphosphine)palladium(II) chloride
(40 mg, 0.0567 mmol) in anhydrous THF (30 mL) degassed
for 20 min, was added freshly distilled anhydrous tri-
ethylamine (5 mL). This was left to stir for 24 h, then
concentrated and redissolved in fresh tetrahydrofuran and
purified by flash column chromatography on silica using
initally dichloromethane to elute an orange impurity,
followed by tetrahydrofuran. Concentration gave a brown
solid which was sonicated first with 10% sodium hydroxide
and filtered, then sonicated with 10% hydrochloric acid and
filtered to give the title compound (0.87 g, 90%) as a yellow
powder, mp .280 8C (from tetrahydrofuran) lmax(THF)/nm
270 (log 1 5.0) and 396 (4.3); nmax(KBr)/cm21 2952m,
2924m, 2851m, 1754s, 1719vs, 1513w, 1493w, 1441m,
1408w, 1275w, 1217m, 1025w, 870w and 660w;
dH(400 MHz; THF-d8) 0.56 (6H, br t, CH3), 0.98 (24H, m,
CH2), 1.27 (4H, m, CH2CH2CH2O), 1.53 (4H, m,
CH2CH2O), 3.74 (4H, t, J¼6.1 Hz, OCH2), 6.78 (2H, s,
Ar), 6.97 (4H, d, J¼8.6 Hz, Ar), 7.23 (4H, d, J¼8.6 Hz, Ar)
and 10.34 (4H, br s, NH); dC(100.5 MHz; THF-d8) 15.5, 24.6,
28.1, 31.2, 31.3, 31.4, 31.6, 31.7, 33.9, 71.2, 88.8, 95.7, 116.0,
118.6, 125.7, 131.1, 133.4, 150.2, 151.1 and 155.9; m/z
(MALDI) 2154.2 (8%), 1717.9 (27) and 1280.6 (94), 847.4
(4), 846.3 (18), 845.3 (56), 844.3 (100) C48H56N6Cl2O8
requires 847.4 (3%), 846.4 (17), 845.4 (57), 844.4 (100).
Method 2. To a stirred solution of N-(4-ethynylphenyl)iso-
cyanuric acid 10 (250 mg, 1.09 mmol), 1,4-dihexadecyloxy-
2,5-diiodobenzene 21 (0.49 g, 0.606 mmol), copper(I)
iodide (15 mg, 0.79 mmol), bis(triphenylphosphine)-
palladium(II) chloride (20 mg, 0.029 mmol) in anhydrous
THF (40 mL) degassed for 20 min, was added freshly
distilled anhydrous Et3N (2 mL). This was left to reflux for
48 h then concentrated and redissolved in fresh THF to dry
load onto a column, and purified by flash column
chromatography on silica initially using dichloromethane
to elute an orange impurity, followed by tetrahydrofuran.
Concentration gave a brown solid which was sonicated first
with 10% sodium hydroxide and filtered, then sonicated
with 10% hydrochloric acid and filtered to give the title
compound (0.44 g, 82%) identical to that reported
previously.
3.2. Crystal structure determination14
Intensity data were recorded at 150 K, using a Nonius
Kappa CCD area-detector diffractometer mounted at the
window of a rotating anode FR591 generator with a
˚
molybdenum anode (l¼0.71073 A). f and v scans were
carried out to fill the Ewald sphere. An empirical absorption
correction was applied using SORTAV. The structure was
solved by direct methods and refined on F 2 by full-matrix
least-squares refinements. Crystallographic data: Formula
¯
C105H150N24O9; M¼1892.49, triclinic space group P1, unit
˚
˚
3.1.25. 1,4-Bis[4-(isocyanuric acid)-3-chlorophenyl-
ethynyl)-2,5-didecyloxybenzene 30. 0.50 g, 94%. Yellow
powder, mp 265 and 289 8C by DSC (from tetrahydrofuran)
cell dimensions a¼14.0756(11) A, b¼18.494(2) A, c¼
˚
22.732(3) A, a¼84.478(8)8 b¼86.697(9)8 g¼69.622(4)8,
3
3
˚
U¼5519.6(10) A , Z¼2, Dc¼1.139 Mg/m , m(Mo Ka)¼
l
n
max(THF)/nm 243 (log 1 4.7), 309 (4.7) and 376 (4.6);
0.075 mm21
.
Colourless plate, crystal size 0.10£
max(KBr)/cm21 3221w, 3087m, 2923s, 2852m, 2213w,
0.02£0.02 mm3. u range for data collection 2.3–25.18;
27,949 collected reflections of which 17,899 are inde-
pendent [Rint¼0.142]. Structure refinement with 17,899 data
for 1253 parameters, GOF¼1.13, final R indices for data
with [F2.2s(F2)] R1¼0.1331, wR2¼0.1690; R indices for
all data R1¼0.2819, wR2¼0.2008. CCDC 225189.
1792m, 1725vs, 1594m, 1506m, 1490m, 1421s, 1277w,
1216m, 1079m, 759m, 595m and 531m; dH(400 MHz;
THF-d8) 0.77 (6H, br t, CH3), 1.29 (28H, m, C7H14), 1.75
(4H, m, OCH2CH2), 3.95 (4H, br t, OCH2), 7.05 (2H, s, Ar),
7.30 (2H, br d, Ar), 7.40 (2H, br d, Ar), 7.55 (2H, s, Ar) and
11.75 (4H, s, NH); dC(100.5 MHz; THF-d8)14.0, 23.1, 26.6,
29.8, 29.9, 30.1, 30.2, 32.4, 69.7, 88.7, 92.9, 114.2, 117.0,
126.4, 130.7, 131.8, 132.5, 132.6, 134.0, 148.6, 148.8 and
154.5 (1 resonance is missing); m/z (MALDI) 1348.9 (16%)
918.5 (3), 917.5 (8), 916.5 (15), 915.5 (40), 914.5 (78),
913.5 (58) and 912.5 (100) C48H54N6Cl2O8 requires 918.3
(2%), 917.3 (8), 916.3 (15), 915.3 (40), 914.3 (80), 913.3
(57) and 912.3 (100).
References and notes
1. Wang, Y.; Wei, B.; Wang, Q. J. Crystallogr. Spectrosc. Res.
1990, 20, 79–84.
2. Ranganathan, A.; Pedireddi, V. R.; Rao, C. N. R. J. Am. Chem.
Soc. 1999, 121, 1752–1753.
3.1.26. 1,4-Bis[4-(isocyanuric acid)phenylethynyl)-2,5-
dihexadecyloxybenzene 31. 0.44 g, 82%. Pale yellow
powder, mp 142–175 8C (from tetrahydrofuran)
3. Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc. 1993, 115,
905–916.
4. (i) Timmerman, P.; Vreekamp, R. H.; Hulst, R.; Verboom, W.;
Reinhoudt, D. N.; Rissanen, K.; Udachin, K. A.; Ripmeester, J.
Chem. Eur. J. 1997, 3, 1823–1832. (ii) Arduini, M.; Crego-
Calama, M.; Timmermann, P.; Reinhoudt, D. N. J. Org. Chem.
2003, 68, 1097–1106. (iii) Bielejewska, A. G.; Marjo, C. E.;
Prins, L. J.; Timmerman, P.; de Jong, F.; Reinhoudt, D. N.
J. Am. Chem. Soc. 2001, 123, 7518–7533.
l
n
max(THF)/nm 229 (log 1 4.7), 279 (4.8) and 357 (4.5);
max(KBr)/cm21 3221br, 3087br, 2921s, 2852m, 1752m,
1716s, 1515m, 1496m, 1442m, 1220m, 760 and 550;
dH(250 MHz; THF-d8) 0.90 (6H, br d, CH3), 1.25 (48H,
m, C12H24), 1.50 (4H, m, CH2), 1.75 (4H, m, OCH2CH2),
3.95 (4H, br t, OCH2), 7.00 (2H, s, Ar), 7.20 (4H, br d, Ar),
7.45 (4H, br d, Ar) and 10.70 (4H, s, NH); dC(62.9 MHz;
THF-d8) 14.0, 23.1, 29.4, 29.5, 29.6, 29.7, 29.9, 30.2, 32.4,
69.7, 87.3, 94.2, 114.4, 117.2, 124.2, 129.6, 131.8, 134.7,
148.7, 149.6 and 154.4; m/z (MALDI) 1012.5 (53%), 819.6
(100) 1016.6 (2), 1015.7 (6), 1014.5 (20), 1013.5 (55) and
1012.5 (100) C60H80N6O8 requires 1016.6 (2%), 1015.6 (7),
1014.6 (25), 1013.6 (70) and 1012.6 (100).
5. (i) Zerkowski, J. A.; Seto, C. T.; Whitesides, G. M. J. Am.
Chem. Soc. 1992, 114, 5473–5475. (ii) Zerowski, J. A.; Seto,
C. T.; Wierda, D. A.; Whitesides, G. M. J. Am. Chem. Soc.
1990, 112, 9025–9026.
6. (i) Tour, J. M.; Rawlett, A. M.; Kozaki, M.; Yao, Y.; Jagessar,
R. C.; Dirk, S. M.; Price, D. W.; Reed, M. A.; Zhou, C.-W.;
Chen, J.; Wang, W.; Campbell, I. Chem. Eur. J. 2001, 23,

6394
M. J. Plater et al. / Tetrahedron 60 (2004) 6385–6394
5118–5134. (ii) Kang, S. K.; Ryu, H. C.; Hong, Y. T. J. Chem.
Soc., Perkin Trans. 1 2001, 7, 736–739.
though. The painting by Masaccio ‘Adam and Eve Banished
from Paradise’ (1424–1428), Brancacci Chapel, Florence,
Italy, depicts the descent of Adam and Eve, hence ‘life’ from
The Garden of Eden.
7. (i) Pelter, A.; Jones, D. E. J. Chem. Soc., Perkin Trans. 1 2000,
14, 2289–2294. (ii) Swager, T. M.; Gil, C. J.; Wrighton, M. S.
J. Phys. Chem. 1995, 99, 4886–4893.
14. Data collection and cell refinement: Otwinowski, D. Z.;
Minor, W. Methods Enzymol. 1997, 276–307. Carter, C. W.,
Jr., Sweet, R. M., Eds. Macromolecular crystallography, part
A; Academic, pp 307–326. Blessing, R. H. Absorption
correction. SORTAV Acta Crystallogr. 1995, A51, 33–38.
Blessing, R. H. J. Appl. Crystallogr. 1997, 30, 421–426.
Sheldrick, G. M. Structure solution and refinement:
SHELXS97. Acta Crystallogr. 1990, A46, 467–473.
8. Zhou, Q.; Swager, T. M. J. Am. Chem. Soc. 1995, 117,
12593–12602.
9. Maruyama, S.; Kawanishi, Y. J. Mater. Chem. 2002, 12,
2245–2249.
10. Mohr, B.; Enkelmann, V.; Wegner, G. J. Org. Chem. 1994, 59,
635–638.
11. Peng, Z.; Gharavi, A. R.; Yu, L. J. Am. Chem. Soc. 1997, 119,
4622–4632.
¨
Sheldrick, G. M. SHELXL97; University of Gottingen:
12. Kuroda, K.; Swager, T. M. J. Chem. Soc., Chem. Commun.
2003, 26–27.
Germany, 1997. Crystallographic data (excluding structure
factors) have been deposited with the Cambridge Crystal-
lographic Data Centre as supplementary publication no.
CCDC 225189 1. Copies of the data can be obtained, free of
charge, on application to CCDC, 12 Union Road, Cambridge
CB2 1EZ, UK (fax: þ44-1223-336033 or e-mail: deposit@
ccdc.cam.ac.uk).
13. We have named this proposed network ‘The Garden of Eden’
owing to its aesthetic symmetry and its anticipated potential,
with mixtures of modified melamines, to mimic a process by
which life might have originated on earth. The Garden of Eden
described in the Bible is not ascribed hexagonal symmetry