H. Zhang et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 174 (2017) 230–235
231
2
. Materials and Methods
2.2.2. Preparation and Characterization of 3
To a 100 mL radius flask, compound 2 (6.64 g, 20 mmol) and sodium
methoxide (1.08 g, 20 mmol) in methanol (40 mL) was refluxed for 8 h
2
.1. Instruments and Materials
4 2
while CuSO ·5H O served as catalyst. Then the crude product was evap-
All chemicals and solvents were of analytical grade and bought from
orated in vacuum and the residue was added HCl (1 mol/L, 30 mL) to
Sigma-Aldrich (St. Louis, MO) without further purification. The solu-
tions of cation were prepared from their chloride salts. Fresh double dis-
tilled water was used throughout the experiment.
crystallize out. Subsequently, a solid separated by filtration was purified
by chromatography on a silica gel column in dichloromethane to give a
1
white product (4.93 g) in 87% yield. H NMR (DMSO-d
6
, 600 MHz): δ
A pH meter (Mettler Toledo, Switzerland) was used to determine the
pH. Ultraviolet-visible (UV–vis) spectra were recorded on a Cary 50 Bio
UV–Visible spectrophotometer and fluorescence spectra were mea-
sured on F-7000 FL fluorescence spectrophotometer. A PO-120 quartz
cuvette (10 mm) was purchased from Shanghai Huamei Experiment In-
strument Plants, China. H NMR and C NMR spectra were recorded on
a Bruker AVANCE III-600 MHz and 150 MHz NMR spectrometer (Bruker,
Billerica, MA) respectively, using tetramethylsilane as the internal stan-
dard for chemical shifts. ESI-MS was carried out on AB Triple TOF
(ppm): 8.49 (d, J = 8.3 Hz, 1H), 8.46 (d, J = 7.2 Hz, 1H), 8.42 (d, J =
8.2 Hz, 1H), 7.79 (t, J = 7.8 Hz, 1H), 7.29 (d, J = 8.3 Hz, 1H), 4.12 (s,
3H), 4.01 (t, J = 7.4 Hz, 2H), 1.60 (m, 2H), 1.35 (d, J = 14.8, 7.4 Hz,
2H), 0.93 (t, J = 7.4 Hz, 3H). 13C NMR (DMSO-d
6
, 150 MHz): δ (ppm):
163.99, 163.36, 160.74, 133.70, 131.46, 128.97, 128.66, 126.83, 123.18,
122.34, 114.69, 106.71, 57.08, 30.18, 20.29, 14.20 (Fig. S2).
1
13
2.2.3. Preparation and Characterization of 4
Compound 3 (4.25 g, 15 mmol) was added to 55% HI solution with
refluxing at 140 °C for 7 h, and then the mixture solution was cooled
to room temperature. After that, the mixture was slowly poured into
ice water, filtered and washed with distilled water. The pale yellow
5
600plus System (AB SCIEX, Framingham, USA). The ability of probe
3
+
reacting to Ho in the living cells was also evaluated by laser confocal
fluorescence imaging using Airyscan confocal laser scanning
microscope.
solid thus obtained was dried under vacuum to give compound D
1
(
(
3.76 g) in 93% yield. H NMR (DMSO-d
6
, 600 MHz): δ (ppm): 11.88
s, 1H), 8.54 (d, J = 8.3 Hz, 1H), 8.48 (d, J = 7.2 Hz, 1H), 8.36 (d, J =
2
2
.2. Preparation and Characterization of Probe
8.1 Hz, 1H), 7.77 (t, J = 7.7 Hz, 1H), 7.16 (d, J = 8.1 Hz, 1H), 4.02 (t,
J = 7.3 Hz, 2H), 1.60 (m, 2H), 1.34 (m, 2H), 0.92 (t, J = 7.3 Hz, 3H).
C NMR (DMSO-d , 150 MHz): δ (ppm): 164.13, 163.46, 160.70,
6
13
.2.1. Preparation and Characterization of 2
The synthesis approach of probe is summarized in Scheme 1. A mix-
134.02, 131.59, 129.64, 129.34, 126.08, 122.84, 122.28, 113.08, 110.42,
30.22, 20.29, 14.21 (Fig. S3).
ture of 4-bromo-1, 8-naphthalic anhydride (8.31 g, 30 mmol) and n-
butylamine (2.19 g, 30 mmol) in ethanol (60 mL) was refluxed for 5 h.
After the reaction was completed, the reaction mixture was evaporated
in vacuum and dried to obtain a solid product. Later on, the solid was
purified by chromatography on a silica gel column in dichloromethane
2.2.4. Preparation and Characterization of the Probe R1
To a stirred trifluoroacetic acid (20 mL), compound 4 (2.69 g,
10 mmol) and hexamethylenetetramine (1.82 g, 13 mmol) was
added, and then the mixture was refluxed at 120 °C for 10 h. When
the remained solution was cooled to room temperature, it was slowly
1
resulted in a pale yellow solid product (8.77 g) in 88% yield. H NMR
(
7
DMSO-d
.6 Hz, 1H), 8.19 (d, J = 7.7 Hz, 1H), 7.98 (t, J = 7.8 Hz, 1H), 4.02 (t,
J = 7.3 Hz, 2H), 1.61 (m, 2H), 1.36 (m, 2H), 0.93 (t, J = 7.4 Hz, 3H).
6
, 600 MHz): δ (ppm): 8.53 (d, J = 7.9 Hz, 2H), 8.30 (d, J =
poured into the mixture solution of CHCl (50 mL) and HCl (1 mol/L,
3
50 mL) and then the mixture was warmed at room temperature whilst
13
C NMR (DMSO-d
6
, 150 MHz): δ (ppm): 163.20, 132.95, 131.94,
stirring overnight. Followed that, separate the organic phase with a
separatory funnel and wash the aqueous phase three times with CHCl3
(20 mL × 3). The merged organic layer was dried with sodium sulfate
1
2
31.74, 131.32, 130.14, 129.51, 129.17, 128.61, 123.10, 122.32, 30.02,
0.27, 14.17 (Fig. S1).
Scheme 1. The synthesis of the probe R1.