Neutral Anion Receptors
J . Org. Chem., Vol. 62, No. 26, 1997 9037
solution was again cooled to 15 °C, 25 mL of fuming nitric acid
(100%) was slowly added, and the mixture was stirred at room
temperature for 3 days. The solution was poured into 250 g
of ice water, and the organic layer was washed with water (3
× 150 mL), saturated NaHCO3 solution (150 mL), and brine
(150 mL). After the mixture was dried with MgSO4, the
solvent was evaporated. Recrystallization from acetone yields
oxou r a n iu m (8): yield 0.30 g (45%); mp 144-145 °C; 1H NMR
(DMSO-d6) δ 9.40 (2H, s), 7.30 (4H, m), 7.16 (2H, d, J ) 7.1
Hz), 6.59 (2H, t, J ) 7.7 Hz), 4.14 (4H, t, J ) 6.3 Hz), 3.98
(6H, s), 1.80 (4H, m), 1.60-1.20 (36H, m), 0.84 (6H, t, J ) 6.4
Hz); 13C NMR (DMF-d7) δ 165.4 (d), 152.2 (s), 150.4 (s), 141.3
(s), 127.9 (d), 125.4 (s), 117.7 (s), 116.6 (d), 105.7 (d), 69.9 (t),
56.8 (q), 32.4 (t), 26.7 (t), 23.1 (t), 14.3 (q); MS-FAB 1013.4
((M + H)+, calcd 1013.5). Anal. Calcd C46H66N2O8U‚MeOH:
C, 54.0; H, 6.6; N, 2.7. Found: C, 53.6; H, 6.8; N, 2.9.
[[4,5-Bis(d od ecyloxy)-1,2-p h en ylen ebis[n itr ilom eth yli-
d yn e (2-h yd r oxy-5-m e t h oxyp h e n yl)]](2-)-N ,N ′,O,O′]d i-
oxou r a n iu m (9): yield 0.32 g (50%); mp 136-139 °C; 1H NMR
(DMSO-d6) δ 9.49 (2H, s), 7.40 (2H, s), 7.34 (2H, d, J ) 3.1
Hz), 7.24 (2H, dd, J ) 3.1 and 9.2 Hz), 6.90 (2H, d, J ) 9.2
Hz), 4.16 (4H, b), 3.76 (6H, s), 1.78 (4H, m), 1.60-1.20 (36H,
m), 0.85 (6H, t, J ) 6.4 Hz); 13C NMR (DMF-d7) δ 165.8 (d),
151.4 (s), 150.4 (s), 141.3 (s), 124.6 (d), 124.3 (s), 122.3 (s), 121.1
(d), 105.7 (d), 69.9 (t), 56.1 (q), 32.4 (t), 26.7 (t), 23.1 (t), 14.3
(q); MS-FAB 1014.0 ((M + H)+, calcd 1013.5). Anal. Calcd
C46H66N2O8U‚MeOH: C, 54.0; H, 6.6; N, 2.7. Found C, 54.0;
H, 6.8; N, 3.0.
[N,N′-[4,5-Bis(d od ecyloxy)-1,2-p h en ylen eb is[n it r ilo-
m eth ylid yn e(2-h yd r oxy-1,3-p h en ylen e)]a ceta m id e](2-)-
N,N′,O,O′]d ioxou r a n iu m (13): yield 0.23 g (30%); mp >300
°C; 1H NMR (DMSO-d6) δ 9.62 (2H, s), 9.20 (2H, s), 8.70 (2H,
s), 7.50 (2H, s), 7.49 (2H, s), 4.18 (4H, t, J ) 5.9 Hz), 2.37 (6H,
s), 1.79 (4H, m), 1.60-1.20 (54H, m), 0.85 (6H, t, J ) 6.4 Hz);
13C NMR (DMSO-d6) δ 168.1 (s), 165.4 (d), 156.8 (s), 149.3 (s),
139.9 (s), 138.3 (s), 129.4 (s), 125.1 (d), 121.9 (d), 105.1 (d),
68.9 (t), 33.7 (s), 31.4 (t), 31.3 (q), 29.1 (t), 29.0 (t), 28.8 (t),
28.7 (t), 25.7 (t), 24.8 (s), 22.1 (t), 13.9 (q); MS-FAB 1179.6
((M + H)+, calcd 1179.6). Anal. Calcd C56H84N4O8U: C, 57.1;
H, 7.2; N, 4.8. Found: C, 57.0; H, 7.2; N, 4.8.
CHEMF ETs. Rea gen ts. High molecular weight (HMW)
PVC was obtained from Fluka. o-Nitrophenyl n-octyl ether
(o-NPOE) was synthesized according to a literature proce-
dure.14 Tetraoctylammonium bromide (TOAB) was purchased
from Fluka. THF was freshly distilled from sodium/benzophe-
none ketyl before use. The anion sodium salts were of
analytical grade (Fluka). All solutions were made with deion-
ized doubly distilled water. Buffer pH 4 was obtained from
Yokogawa. The measurements were carried out in solution
of 0.01 M 4-morpholinomethanesulfonic acid (MES, Fluka)
adjusted to the desired pH with NaOH.
F a br ica tion of CHEMF ETs. CHEMFETs were prepared
from ISFETs with dimensions of 3 × 4.5 mm fabricated in the
MESA cleanroom facilities (University of Twente, The Neth-
erlands). Details of the modification of the ISFETs with poly-
(hydroxyethyl methacrylate) hydrogel (polyHEMA) have been
described before.15 The modified ISFETs were mounted on a
printed circuit board, wire bonded, and encapsulated with
epoxy resin (Hysol H-W 796/C8 W795). The polyHEMA layer
of the CHEMFET was conditioned by immersion in a 0.1 M
solution of the primary ion at pH ) 4 (Yokogawa buffer). The
ion selective membranes were prepared by dissolving in 0.7
mL of THF approximately 100 mg of a mixture composed of
33 wt % PVC, 66 wt % o-NPOE, 1 wt % receptor, and 20 mol
% (with respect to the receptor) TOAB. The membrane was
deposited on the gate area of the CHEMFET by casting this
solution using a capillary. The solvent was allowed to
evaporate overnight.
1
4.0 g (75%) of 2: mp 83-84 °C; H NMR δ 7.29 (2H, s), 4.10
(4H, t, J ) 6.6 Hz), 1.87 (4H, m), 1.52-1.26 (36H, m),0.88 (6H,
t, J ) 6.4 Hz); 13C NMR δ 151.8 (s), 136.5 (s), 107.9 (d), 70.2
(t), 31.9 (t), 29.7 (t), 29.6 (t), 29.4 (t), 29.2 (t), 28.7 (t), 25.8 (t),
22.7 (t), 14.1 (q); MS-FAB m/z 538.1 ((M + 2H)+, calcd 538.4).
Anal. Calcd C30H52N2O6: C, 67.1; H, 9.8; N, 5.2. Found: C,
66.9; H, 9.9; N, 5.3.
1,2-Bis(d od ecyloxy)-4,5-d ia m in oben zen e (3). To a solu-
tion of 1.8 g (3.4 mmol) of 2 in 50 mL of ethanol, 0.1 g of 10%
Pd/C, and 6.3 mL (37 mmol) of hydrazine monohydrate were
added. After 1 night of refluxing, the hot solution was filtered
over Hyflo, while kept under N2. After cooling, the white
precipitate was filtered off and rinsed with cold, O2-free
methanol: yield 1.3 g (80%); mp 73-74 °C; 1H NMR δ 6.38
(2H, s), 3.90 (4H, t, J ) 6.6 Hz), 1.80 (4H, m), 1.52-1.26 (36H,
m), 0.88 (6H, t, J ) 6.4 Hz); 13C NMR δ 143.4 (s), 128.4 (s),
106.8 (d), 70.7 (t), 31.9 (t), 29.7 (2 × t), 29.6 (t), 29.5 (t), 29.4
(t), 26.1 (t), 22.7 (t), 14.1 (q); MS-EI m/z 476.4 (M+, calcd 476.4).
N-(2-Hyd r oxy-4-ter t-bu tylp h en yl)a ceta m id e (11). To a
solution of 1.25 g (8 mmol) of 2-amino-4-tert-butylphenol in
40 mL of dry toluene was slowly added 0.82 g (8 mmol) of acetic
anhydride. The solution was stirred overnight, and after
cooling, a white precipitate was collected: yield 1.5 g (90%);
mp 169-171 °C; 1H NMR δ 8.69 (1H, s), 7.78 (1H, s), 7.14 (1H,
d, J ) 8.0 Hz), 6.99 (1H, s), 6.94 (1H, d, J ) 8.4 Hz), 2.23 (3H,
s), 1.25 (9H, s); 13C NMR δ 170.6 (s), 146.3 (s), 143.6 (s), 124.8
(s), 124.4 (d), 119.4 (d), 119.1 (d), 34.0 (s), 31.4 (q), 23.7 (q);
MS-EI m/z 207.1 (M+, calcd 207.1). Anal. Calcd C12H17NO2:
C, 69.5; H, 8.3; N, 6.8. Found: C, 69.4; H, 8.2; N, 7.0.
N -(3-F o r m y l-2-h y d r o x y -4-t er t -b u t y lp h e n y l)a c e t a -
m id e (12). A mixture of 1.5 g (7.2 mmol) of 11 and 1.01 g
(7.2 mmol) of hexamethylenetetraamine (HMTA) was dissolved
in 150 mL of trifluoroacetic acid and refluxed for 3.5 d. After
the mixture was cooled to 60 °C, 9 mL water was added, and
the resulting mixture was stirred for 2.5 h. The mixture was
dissolved in 150 mL of EtOAc, brought to neutral pH with
NaHCO3, and washed with 150 mL of brine. Evaporation
yields the crude product, which could be purified using column
chromatography (SiO2, CH2Cl2/MeOH 98/2); 1.2 g (70%) of the
product was obtained as a red solid: mp 82-83 °C; 1H
NMR δ 11.31 (1H, s), 9.88 (1H, s), 8.77 (1H, d, J ) 2.2 Hz),
7.72 (1H, b), 7.28 (1H, d, J ) 2.2 Hz), 2.24 (3H, s), 1.34 (9H,
s); 13C NMR δ 197.0 (d), 168.5 (s), 147.9 (s), 143.4 (s), 127.1
(s), 124.7 (d), 123.4 (d), 119.1 (s), 34.5 (s), 31.2 (q), 24.9 (q);
MS-EI m/z 235.1 (M+, calcd 235.1). Anal. Calcd C13H17NO3:
C, 66.4; H, 7.3; N, 6.0. Found: C, 66.5; H, 7.4; N, 6.0.
Gen er a l P r oced u r e for t h e Syn t h esis of UO2 Sa lo-
p h en es 7, 8, 9, a n d 13. A solution of 1.3 mmol of the
appropriate aldehyde (salicyl aldehyde (4), 3-methoxysalicyl
aldehyde (5), 5-methoxysalicyl aldehyde (6), or 12) and 0.3 g
(0.65 mmol) of diamine 3 in 25 mL of methanol was refluxed
for 1 h. Subsequently 0.27 g (0.65 mmol) of UO2(OAc)2‚2H2O
was added, and refluxing was continued for another 1 h. The
precipitate was filtered off and washed with methanol to yield
7, 8, 9, and 13 as an orange or red solid.
CHEMF ET Mea su r em en ts. CHEMFETs were condi-
tioned in a 0.1 M solution of the sodium salt of the primary
ion for one night, before starting the measurements. The
output signal of the CHEMFETs was measured in a constant
drain-current mode (Id ) 100 µA), with a constant drain-
source potential (Vds ) 0.5 V).16 This was achieved using an
ISFET amplifier of the source-drain follower type (Electro
[[4,5-Bis(d od ecyloxy)-1,2-p h en ylen ebis[n itr ilom eth yli-
d yn e(2-h yd r oxyp h en yl)]](2-)-N,N′,O,O′]d ioxou r a n iu m
(7): yield 0.28 g (45%); mp 151-154 °C; 1H NMR (DMSO-d6)
δ 9.56 (2H, s), 7.79 (2H, d, J ) 3.0 Hz), 7.60 (2H, t, J ) 7.4
Hz), 7.46 (2H, s), 6.99 (2H, d, J ) 9.3 Hz), 6.73 (2H, t, J ) 7.5
Hz), 4.18 (4H, b), 1.79 (4H, m), 1.60-1.20 (36H, m), 0.85 (6H,
t, J ) 6.4 Hz); 13C NMR (DMSO-d6) δ 169.4 (s), 164.8 (d), 149.1
(s), 140.1 (s), 135.5 (d), 135.3 (d), 124.3 (s), 120.5 (d), 116.5
(d), 105.1 (d), 68.9 (t), 31.3 (t), 29.1 (t), 29.0 (t), 28.2 (t), 28.7
(t), 25.7 (t), 22.1 (t), 13.9 (q); MS-FAB 953.3 ((M + H)+, calcd.
953.5). Anal. Calcd C44H62N2O6U‚1.5H2O: C, 53.9; H, 6.6; N,
2.9. Found: C, 54.1; H, 6.6; N, 2.9.
(13) Dangerous Properties of Industrial Materials, 5th ed.; Sax, N.
I., Ed.; van Nostrand Reinhold Co.: New York, 1979; pp 1078-1079.
(14) Ikeda, I.; Yamazaki, H.; Konishi, T.; Okahara, M. J . Membr.
Sci. 1989, 46, 113-119.
(15) Sudho¨lter, E. J . R.; van der Wal, P. D.; Skowronska-Ptasinska,
M.; van den Berg, A.; Bergveld, P.; Reinhoudt, D. N. Anal. Chim. Acta
1990, 230, 59-65.
[[4,5-Bis(d od ecyloxy)-1,2-p h en ylen ebis[n itr ilom eth yli-
d yn e(2-h yd r oxy-3-m et h oxyp h en yl)]](2-)-N,N′,O,O′]d i-
(16) Bergveld, P. Sens. Actuators 1981, 1, 17-29.