Full Paper
1
TBA ·TP: Terephthalic acid (0.332 g, 2.00 mmol) was suspended in
[1·P] : White crystals. Yield: 24 mg (0.073 mmol, 73%). H NMR
2
n
water (10 mL) and a 1.0m solution of tetrabutylammonium hydrox-
ide in methanol (4.00 mL, 4.00 mmol) was added, which caused
most of the acid to dissolve. The solution was stirred at room tem-
perature for 2 min, filtered to remove a small amount of insoluble
solid, and taken to dryness under reduced pressure. Analysis at this
([D ]DMSO containing 2 drops conc. DCl(aq)): d=9.76* (br.s), 9.46*
6
(br.s), 8.03 (s, 4H), 7.61–7.65 (m, 2H), 7.54–7.58 ppm (m, 2H).
*These signals integrate to a value lower than the expected value
of 4H, presumably as a result of H/D exchange. IR: n˜ =1693, 1542
À1
(s), 1388 cm (s).
1
1
point by H NMR spectroscopy indicated a product of approximate-
[2·TP] : White crystals. Yield: 13 mg (0.040 mmol, 40%). H NMR
n
ly 95% purity. This was taken up in methanol (30 mL) and filtered
to remove a small amount of insoluble solid, which was washed
with more methanol (2ꢂ5 mL). The combined filtrate was taken to
dryness under reduced pressure. The resulting white solid was
([D ]DMSO containing 2 drops conc. DCl(aq)): d=9.77* (br.s), 9.48*
6
(br.s), 8.47 (s, 1H), 8.15 (d, J=7.9 Hz, 2H), 8.01 (s, 4H), 7.80 ppm (t,
À1
J=7.9 Hz, 1H). IR: n˜ =1501 (s), 1372 cm (s).
1
[2·IP] : White crystals. Yield: 24 mg (0.073 mmol, 73%). H NMR
n
dried in vacuo to give TBA ·TP as white powder. Yield: 0.931 g
([D ]DMSO containing 2 drops conc. DCl(aq)): d=9.76* (br.s), 9.46*
2
6
1
(
1.43 mmol, 72%). H NMR ([D ]DMSO): d=7.62 (s, 4H), 3.16 (t, J=
(br.s), 8.45 (s, 1H), 8.43 (s, 1H), 8.11–8.16 (m, 4H), 7.98 (t, J=7.9 Hz,
1H), 7.62 (t, J=7.7 Hz, 1H). *These signals integrate to a value
lower than the expected value of 4H, presumably as a result of H/
6
7
.5 Hz, 16H), 1.52–1.60 (m, 16H), 1.26–1.35 (m. 16H), 0.93 ppm (t,
1
3
J=7.5 Hz, 24H). C NMR ([D ]DMSO): d=168.4, 141.6, 127.4, 57.5,
6
+
À1
2
3.1, 19.2, 13.5 ppm. MS (ESI+): m/z: 242.4 [C H N] . MS (ESIÀ):
D exchange. IR: n˜ =1604, 1518 (s), 1375 cm (s).
16
36
À
À1
1
m/z: 165.1 [C H O ·H] . IR: n˜ =1577 (s, C=O stretch), 1348 cm (s,
[2·P] : White crystals. Yield: 20 mg (0.061 mmol, 61%). H NMR
8
4
4
n
CÀO stretch).
([D ]DMSO containing 2 drops conc. DCl(aq)): d=9.77* (br.s), 9.47*
6
TBA ·IP: Isophthalic acid (0.332 g, 2.00 mmol) was suspended in
(br.s), 8.48 (s, 1H), 8.15 (d, J=7.9 Hz, 2H), 7.81 (t, J=7.9 Hz, 1H).
7.61–7.66 (m, 2H), 7.55–7.59 ppm (m, 2H). *These signals integrate
to a value lower than the expected value of 4H, presumably as
2
water (10 mL) and a 1.0m solution of tetrabutylammonium hydrox-
ide in methanol (4.00 mL, 4.00 mmol) was added, which caused
most of the acid to dissolve. The solution was stirred at room tem-
perature for 2 min, filtered to remove a small amount of insoluble
solid, and then taken to dryness under reduced pressure. Analysis
À1
a result of H/D exchange. IR: n˜ =1669, 1513 (s), 1373 cm (s).
MD simulations
1
at this point by H NMR spectroscopy indicated a product of ap-
proximately 95% purity. This was sonicated in acetone/methanol
[28]
The GROMACS version 5.1.2 molecular dynamics package,
in
[29]
(
2:1 v/v, 15 mL) and filtered to remove a white solid. The filtrate
conjunction with the GROMOS 54A7 force field, was used in all
MD simulations. This force field was chosen primarily for its ability
to generate parameters automatically and accurately for carboxyl-
ate and amidinium species using the Automated Topology Builder
was dried in vacuo to give TBA ·IP as a hygroscopic white solid.
Yield: 1.02 g (1.57 mmol, 79%). H NMR ([D ]DMSO): d=8.28 (s,
2
1
6
1
1
7
1
H), 7.66 (d, J=7.4 Hz, 2H), 7.01 (t, J=7.4 Hz, 1H), 3.14–3.20 (m,
6H), 1.52–1.60 (m, 16H), 1.25–1.34 (m. 16H), 0.92 ppm (t, J=
.3 Hz, 24H). C NMR ([D ]DMSO): d=169.1, 140.8, 130.0, 128.6,
24.9, 57.5, 23.1, 19.2, 13.5 ppm. MS (ESI+): m/z: 242.4 [C H N] .
[30]
(ATB). Parameters generated by the ATB are able to reproduce
the free energy of solvation for small organic molecules with
1
3
6
+
À1
16
36
a mean unsigned error of 6.7 kJmol based on a test set of 214
À
À
MS (ESIÀ): 165.1 [C H O ·H] , 406.3 [C H N·C H O ] . IR: n˜ =1604
molecules including many relevant to the systems studied in this
8
4
4
16 36
8
4
4
À1
[31]
(
[
s, C=O stretch), 1343 cm (s, CÀO stretch).
1·TP] : A solution of 1·2Cl (24 mg, 0.10 mmol) in water (5 mL) was
work.
n
Water was represented explicitly using the simple point charge
[32]
layered with water (2.5 mL) and then TBA ·TP (65 mg, 0.10 mmol)
in water (2.5 mL). Within a few minutes, a white microcrystalline
solid was visible. After a few days, the solid was isolated by filtra-
(SPC) model. Parameters for all other molecules were taken from
2
[30]
the Automated Topology Builder. Each system contained 10 bi-
s(amidinium) cations, 10 dicarboxylate anions, and 5700 solvent
molecules and was simulated under periodic boundary conditions
in a rectangular simulation box with a timestep of 2 fs. The tem-
perature of the system was maintained by coupling each compo-
nent of the system to an external temperature bath at 298 K with
tion, washed with water (3ꢂ5 mL), and dried in vacuo. Yield:
1
2
0 mg (0.061 mmol, 61%). H NMR ([D ]DMSO containing 2 drops
6
conc. DCl(aq)): d=9.77* (br.s), 9.51* (br.s), 8.05 (s, 4H), 8.02 ppm (s,
H). *These signals integrate to a value lower than the expected
4
value of 4H, presumably as a result of H/D exchange. IR: n˜ =1706,
a coupling constant of t =0.1 ps using a velocity rescaling ther-
mostat. The pressure was maintained at 1 bar (1 bar=0.1 MPa) by
T
À1
1
476 (s), 1373 cm (s). Crystals suitable for SCXRD were obtained
by repeating the synthetic procedure described above at a lower
concentration (1–2 mg of 1·2Cl in ꢀ1 mL water).
weakly coupling the system to a semi-isotropic pressure bath
using an isothermal compressibility of 4.5ꢂ10 bar and a cou-
À5
À1
pling constant of t =0.5 ps. During the simulations, the length of
P
all bonds within the tectons and non-water solvents were con-
[33]
[34]
strained using the LINCS algorithm. The SETTLE algorithm was
used to constrain the geometry of the water molecules. Electro-
static interactions were calculated using particle mesh Ewald sum-
mation, and nonbonded interactions were calculated with a cut-off
of 1.0 nm. Both were updated each timestep. Each simulation
system was simulated in triplicate for 100 ns. All images were pre-
General procedure for synthesis of [1·IP] , [1·P] [2·TP] , [2·IP] ,
n
n
n
n
and [2·P] : A solution of TBA ·TP or TBA ·IP (65 mg, 0.10 mmol) or
n
2
2
Na ·P (21 mg, 0.10 mmol) in water (2.5 mL) was added to a solution
2
of 1·2Cl or 2·2Cl (24 mg, 0.10 mmol) in water (2.5 mL). The result-
ing clear, colorless solution was subjected to acetone vapor diffu-
sion, which resulted in the formation of colorless crystals or white
microcrystals that were isolated by filtration, washed with acetone
[35]
pared in VMD.
(
[
(
(
5ꢂ2 mL), and dried in vacuo.
X-ray crystallography
1
1·IP] : White crystals. Yield: 25 mg (0.076 mmol, 76%). H NMR
n
[D ]DMSO containing 2 drops conc. DCl(aq)): d=9.76* (br.s), 9.46*
Single crystal data were collected using mirror-monochromated
6
br.s), 8.43 (s, 1H), 8.13 (d, J=7.7 Hz, 2H), 8.03 (s, 4H), 7.62 (t, J=
CuK radiation at 150 K with an Agilent Supernova diffractometer.
a
7
.7 Hz, 1H). *These signals integrate to a value lower than the ex-
Raw frame data (including data reduction, interframe scaling, unit-
cell refinement, and absorption corrections) were processed using
CrysAlis PRO. Structures were solved with SUPERFLIP and were
pected value of 4H, presumably as a result of H/D exchange. IR:
n˜ =1673, 1604, 1550 (s), 1372 cm (s).
À1
[36]
[37]
&
&
Chem. Asian J. 2017, 00, 0 – 0
10
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÝÝ These are not the final page numbers!