FUNCTIONALIZED EU(III)-BASED NANOSCALE METAL-ORGANIC FRAMEWORK
625
source at room temperature. The singlet oxygen quantum
and the precipitate was acidified by adding 1 M of dilute
hydrochloric acid to collect a solid to obtain 1.6 g white
powder. H NMR (400 MHz, CDCl3) d 8.56 (s, 2H),
yields were determined a UV-vis spectrophotometer (TU-
1901). The fluorescence intensity of zinc phthalocyanine
in the cells was monitored by flow cytometry (C6, BD
BioSciences). Cell Counting Kit-8 (CCK-8) was obtained
from Beyotime Institute of Biotechnology. Confocal laser
scanning microscopy (CLSM) images were performed
on an Olympus FV1000-IX81 CLSM and a Leica TCS
SP confocal system (Leica, Germany).
1
7.36–7.27 (m, 5H), 4.28 (s, 2H), 3.89 (s, 3H), 3.87 (s, 6H).
Preparation of Trimethyl 2-aminobenzene-1,3,5-
tricarboxylate (Y4). 2 g (5.6 mmol) of Y3, 0.56 g of
Pd/C was dissolved in a mixed solution of 65 mL of
tetrahydrofuran and 20 mL of isopropanol and reacted
at room temperature for 2 days under a hydrogen
atmosphere. After the reaction was completed, the
mixture was filtered through celite and washed with
dichloromethane. The filtrate was spun dry to obtain
1.25 g white powder. 1H NMR (400 MHz, CDCl3) d8.76
(s, 2H), 8.60 (s, 2H), 3.91 (s, 6H), 3.90 (s, 3H).
Synthesis
Preparation of tetrakis (4-carboxylphenoxy) phthalo-
cyanine zinc (ZnPc-TCP). ZnPc-TCP was carried
out under conditions reported by Ke et al. [35] using
3-nitrophthalonitrile, 4-(butoxycarbonyl) phenol and
anhydrous K2CO3 in dry DMSO, followed by filtration
and washing. Zinc acetate and DBU were reacted with
the above procedure, finally followed by hydrolysis.
Compound ZnPc-TCP was obtained as a green solid
Preparation of 2-aminobenzene-1,3,5-tricarboxylic
acid (Y5). 3 g (11.2 mmol) of Y4 was dissolved in 50 mL
of tetrahydrofuran and 100 ml of water, and 30 mL of a
2 M KOH solution was added, and the mixture was heated
to 50°C overnight. After the reaction was completed, the
organic solvent was removed and the aqueous phase was
acidified with dilute hydrochloric acid to give a white
1
(Yield 22.5%). H NMR (400 MHz, DMSO) d9.00 (s,
1
2H), 8.38 (d, J = 22.0 Hz, 2H), 7.92 (d, J = 37.5 Hz, 14H),
7.29 (d, J = 63.3 Hz, 10H). MS (ESI): (m/z) 1121.1473
{80%, [M + H]+}.
powder (2.1 g). H NMR (400 MHz, CDCl3) d13.06
(s, 3H), 8.61 (s, 2H), 8.58 (s, 2H).
Preparation of EuBTC-NH2. The precursor solu-
.
Preparation of 2-amino-1,3,5-benzenetricarboxylic
acid. Synthesis of 2-aminotrimethylenetricarboxylic acid
ligands was carried out under conditions reported by
Peikert et al. [36], with some improvements.
tion 60 mg (0.135 mmol) Eu(NO3)3 6H2O, 20 mg
(0.090 mmol) Y5 and DMF (3 mL) were placed in a
centrifuge tube. Then 0.73 g polyvinyl pyrrolidone
(PVP) and 24.6 mg sodium acetate were dissolved in a
mixed solution containing DMF (3 mL), ethanol (4 mL)
and H2O (4 mL). The precursor solution was added to the
mixed solution. Next, the final solution was shifted to a
glass vial and heated to 120°C for 18 h. The precipitates
were washed with DMF three times, ethanol two times,
then the sample powder was dried under vacuum and a
pale yellow powder was obtained.
Preparation of EuBTC-Pc. 20 mg ZnPc-TCP was
dissolved in 4 mL DMF and 8.5 mg (0.05 mmol) 1-ethyl-
3-(3-dimethylaminopropyl) carbodiimide (EDCI) and
6.0 mg (0.05 mmol) 1-hydroxybenzotriazole (HOBT)
was added. The mixed solution was kept stirring at 0°C
for about 30 min. Then 5 drops of triethylamine were
added to maintained the system pH at 7–8. Next, 20 mg
EuBTC-NH2 was added and stirred overnight when the
temperature was raised to room temperature. After the
reaction, the sample was collected by centrifugation,
washed with DMF and ethanol. The sample was dried
under vacuum and a blue powder was obtained.
Preparation of FA-EuBTC-Pc. 35.0 mg (0.08 mmol)
FA was dissolved in a water-DMSO mixture (1:1v/v,
8 mL), and 0.2 mL triethylamine was added to keep the
pH at about 8. Then 32 mg (0.17 mmol) 1-Ethyl-3-(3′-
dimethylaminopropyl) carbodimi-de (EDC) and 18 mg
(0.16 mmol) N-Hydroxysuccinimide (NHS) were added.
The mixture was stirred for 4 h at room temperature
under dark conditions. After 4 h, 20 mg EuBTC-Pc was
added to the FA solution and the mixture was stirred for
24 h under dark. The sample was washed with H2O and
Preparation of trimethyl 2-bromobenzene-1,3,5-
tricarboxylate (Y2). 5 g (25 mmol) of 2-bromo-1,3,5-
trimethylbenzene and 300 mL of boiling water were
mixed and stirred for 10 min, 26 g (0.16 mol) of
potassium permanganate added, and then all mixtures
were heated to reflux. After 72 h, 50 mL of methanol
was added, and the reaction was stirred at 60°C for 5 h
to remove unreacted potassium permanganate. Next, the
mixture was filtered and washed with boiling water, then
the collected filtrate was removed by rotary evaporation
and acidified to pH = 1 with 50% sulfuric acid. The
white powder was precipitated to obtain a solid powder
of 3.4 g 2-bromobenzene-1,3,5-tricarboxylic acid. 3 g
(10.4 mmol) of 2-bromobenzene-1,3,5-tricarboxylic acid
was dissolved in 60 mL methanol, and 3 mL concentrated
sulfuric acid was added dropwise. The mixture was
heated under reflux for 6 h, and then was poured into
ice water. The pH was adjusted to neutral with saturated
sodium hydrogen carbonate, and the precipitate was
collected by filtration to yield 1.8 g of white powder. 1H
NMR (400 MHz, CDCl3) d8.35 (s, 2H), 3.98 (s, 6H),
3.96 (s, 3H).
Preparation of trimethyl 2-(benzylamino)benzene-
1,3,5-tricarboxylate (Y3). 2 g (6.1 mmol) of Y2 was
dissolved in a mixed solution of 30 mL of methanol,
15 mL of dioxane, and 4.5 mL of benzylamine, and stirred
at room temperature for 10 min, then transferred to an
oven at 40°C for 4 h. After the reaction was completed,
the solvent was spun off, 50 mL of water was added,
Copyright © 2019 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2019; 23: 625–627
Chen, Pan
