Supporting Information
© Wiley-VCH 2008
69451 Weinheim, Germany
S1
Supporting Information for
An Unlockable-Relockable Iron Cage via Subcomponent Selfassembly
Prasenjit Mal, David Schultz, Kodiah Beyeh, Kari Rissanen* and Jonathan R. Nitschke*
[∗]
Dr. J.R. Nitschke, Dr. P. Mal
University of Cambridge, Department of Chemistry
Lensfield Road, Cambridge CB2 1EW, UK
E-mail: [email protected]
[∗]
Acad. Prof. Dr. K. Rissanen, M. Sc. K. Beyeh
Nanoscience Center, Department of Chemistry
University of Jyväskylä, P.O. Box 35, 40014 JYU, Finland
E-mail: [email protected]
Dr. D. Schultz
University of Edinburgh, School of Chemistry
The King’s Buildings, West Mains Road, Edinburgh EH9 3JJ, UK
S2
Preparation of the C6H12⊂1 complex. Cage 1 (107 mg, 0.02 mmol) was loaded into a
Teflon-capped NMR tube, then D2O (3.0 mL) and excess cyclohexane (0.1 mL, 1.52 mmol,
which formed an organic phase above the water) were added and the mixture was degassed
with three vacuum / N2 cycles. The sealed tube was heated in an oil bath to 323K, and
reaction progress was monitored by NMR (Figure S1). Cyclohexane was observed to
incorporate into 1, leading to complete formation of C6H12⊂1 after 6 h at 323 K. After
removal of the excess cyclohexane and water under dynamic vacuum, a dark purple powder
was obtained; yield 101 mg (92%); 1H NMR (500 MHz, 300 K, D2O, referenced to 2methyl-2-propanol at 1.24 ppm as internal standard): 1H NMR (500 MHz, 300 K, D2O,
referenced to 2-methyl-2-propanol at 1.24 ppm as internal standard): δ = 10.12 (s, 12 H,
imine), 8.97 (d, J = 7.5 Hz, 12 H, 3-pyridine), 8.39 (t, J = 7.5 Hz, 12 H, 4-pyridine), 8.15 (s,
br, 12 H, 6,6’-benzidine), 8.03 (t, J = 6.0 Hz, 12 H, 5-pyridine), 7.32 (d, J = 8.0 Hz, 12 H,
6-pyridine), 6.47 (s, 12 H, 3,3’-benzidine), 6.12 (d, J = 7.0 Hz, 12 H, 5,5’-benzidine), 3.19
(s, tetramethylammonium) ppm; 13C NMR (125 MHz, 300 K, D2O, referenced to 2-methyl2-propanol at 30.29 ppm as internal standard): δ = 174.6, 157.2, 156.8, 152.9, 143.1, 140.6,
136.7, 134.3, 134.2, 133.1, 123.8, 121.7 ppm.
S3
+
NMe4
h
0
=
t
a
tBuOH
acetone free
C6H12
︶
h
1
=
t
b
︶
h
6
=
t
d
︶
h
3
=
t
c
︶
trapped
C6H12
7.5
m
p
p
10.0
5.0
2.5
0.0
Figure S1. The incorporation of cyclohexane into 1
The liberation of cyclohexane from C6H12⊂1 upon reaction with 2. C6H12⊂1 (4.0 mg,
0.94 μmol), D2O (0.5 mL) and tris(2-ethylamino)amine 2 (2.07 mg, 14.15 μmol) were
loaded into a Teflon-capped NMR tube and the solution was degassed with three vacuum /
N2 cycles. The sealed tube was heated in an oil bath to 323K, and reaction progress was
monitored by NMR (Figure S2). The appearance was noted of 1H resonances corresponding
to 3, free 4,4’-diaminobiphenyl-2,2’-disulfonate, and free cyclohexane. The reaction had
reached completion after 72 h at 323 K.
S4
Fe2+
N
N
4
N
NH2
-
O3S
2
1'
2'
NH2
H2N
SO3-
8
N
Fe2+
N
3''
7
1 N N N
Fe
2
4
N N N
3
4
5
Fe
1''
2''
-
6 O3S
SO3-
6
3
H2N
Fe2+
2+
H2N
2+
N
C6H12 1
Scheme S1. Liberation of the hexane guest within 1 via the addition of chelating
amine 2.
a
trapped
C6H12
︶
b
free
C6H12
︶
c
︶
8
7
'
'
3
'
'
'1
'
62
'
2
'
1
5
4
3
1
d
︶
7.5
m
p
p
10.0
5.0
2.5
0.0
Figure S2. The products of the reaction of C6H12⊂1 with tris(2-ethylamino)amine:
a) C6H12⊂1; b) C6H12⊂1 followed by addition of tris(2-ethylamino)amine (15.0 equiv
12 h at 323 K); c) after 36 h at 323 K; d) after 72 h at 323 K.
S5
The liberation of cyclohexane from C6H12⊂1 upon reaction with acid; the
regeneration of C6H12⊂1 following reaction with base in the presence of excess
cyclohexane. C6H12⊂1 (4.0 mg, 0.94 μmol) was dissolved in D2O (0.5 mL) in a Tefloncapped NMR tube, then p-toluenesulfonic acid (1.8 mg, 9.4 μmol) was added and the
solution was degassed with three vacuum / N2 cycles. The sealed tube was heated in an oil
bath to 323K, and reaction progress was monitored by NMR (Figure S3). The color
changed from dark purple to colorless and 1H resonances corresponding to protonated 2formylpyridine, free 4,4’-diaminobiphenyl-2,2’-disulfonate, and free cyclohexane were
observed to grow into the spectrum. The reaction had reached completion after 60 h at 323
K. The addition of NaHCO3 (1.2 mg, 14.1 μmol) followed by addition of excess
cyclohexane (ca. 25 μL) to this solution resulted in the reappearance of the dark purple
color of 1, and after 6 h at 323 K the 1H NMR spectrum of C6H12⊂1 was observed to have
completely regenerated (Figure S3).
Scheme S2. The acid-mediated liberation of cyclohexane from C6H12⊂1 followed
by the base-mediated regeneration of C6H12⊂1.
S6
tBuOH
+
NMe4
a
acetone
︶
b
︶
c
free
C6H12
︶
d
trapped
C6H12
︶
7.5
m
p
p
10.0
5.0
2.5
0.0
Figure S3. 1H NMR spectra of a) cage 1; b) C6H12⊂1; c) C6H12⊂1 following
reaction with tosylic acid (10 equiv, 60 h at 323 K); d) regeneration of C6H12⊂1
following addition of excess cyclohexane and sodium bicarbonate (15 equiv, 6 h at
323 K).
S7
The liberation of cyclohexane from C6H12⊂1 upon reaction with acid; the
regeneration of C5H10⊂1 following reaction with base in the presence of excess
cyclopentane. C6H12⊂1 (4.0 mg, 0.94 μmol) was dissolved in D2O (0.5 mL) in a Tefloncapped NMR tube, then p-toluenesulfonic acid (1.8 mg, 9.4 μmol) and excess cyclopentane
(ca. 25 μL) were added and the solution was degassed with three vacuum / N2 cycles. The
sealed tube was heated in an oil bath to 323K, and reaction progress was monitored by
NMR (Figure 2 in the main text). The color changed from dark purple to colorless and 1H
resonances corresponding to protonated 2-formylpyridine and free 4,4’-diaminobiphenyl2,2’-disulfonate were observed to grow in to the spectrum. The reaction had reached
completion after 60 h at 323 K. The addition of NaHCO3 (1.2 mg, 14.1 μmol) to this
solution resulted in the reappearance of the dark purple color of 1, and after 6 h at 323 K
the 1H NMR spectrum of C5H10⊂1 was observed (Figure 2 in the main text).
Scheme S3. The liberation of cyclohexane from C6H12⊂1 followed by the
generation of C5H10⊂1.
S8
Separation of cyclohexane and cyclopentane. A solution of 1 (105 mg, 0.02 mmol) in
D2O (3.0 mL) in the presence of excess cyclohexane (0.05 mL, 0.76 mmol) and
cyclopentane (0.05 mL, 0.95 mmol), which formed an organic phase above the water, was
prepared and degassed in a sealed Teflon-capped NMR tube. The mixture was heated to
323 K and monitored by NMR (Figure S4). Both cyclohexane and cyclopentane were
observed by 1H NMR to incorporate into 1, leading to the complete formation of a 1.40 : 1
mixture of C6H12⊂1 and C5H10⊂1 after 16 h at 323 K. The excess cyclohexane,
cyclopentane and water were lyophilized (<0.01 Torr), which gave a dark purple powder
that was kept under dynamic vacuum (<0.01 Torr) at 323 K for 4 h. The purple powder was
then redissolved in water (3.0 mL) and the water was again lyophilized and the product
heated for 3 h at 323 K under dynamic vacuum (<0.01 Torr), giving a purple finely-divided
product (98 mg). The NMR spectra (Figure S4) of this product corresponded to a 1.35 : 1 :
0.07 mixture of empty 1, C6H12⊂1, and C5H10⊂1. The cyclohexane could be removed from
the cage after the treatment with tosylic acid as noted above.
S9
Scheme S4. Vacuum separation of Cyclohexane and Cyclopentane using 1.
S10
+
NMe4
tBuOH
a
acetone
︶
b
︶
c
︶
1.00
1.40
d
︶
7.5
m
p
p
1.35
1.00
0.07
10.0
5.0
2.5
0.0
Figure S4. 1H NMR spectra of a) cage 1 (█); b) C6H12⊂1(●); c) C6H12⊂1 and
C5H10⊂1 mixture (♦ for C5H10⊂1); d) mixture of products after removal of C5H10
from the mixture via lyophylization.