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5.37 Hz, 1H), 7.15–7.26 (m, 2H), 7.40–7.50 (m, 2H), 7.65 (dd, J=
Characterization
4.70, 10.23 Hz, 2H), 8.10–8.21 ppm (m, 2H).
1H NMR spectra were measured using INOVA 400 MHz NMR spec-
trometers, with CDCl3 or [D6]DMSO as solvent and tetramethylsi-
lane (TMS) as the internal standard at ambient temperature. Molec-
ular weights and polydispersity indexes (PDIs), relative to PMMA,
were measured using Waters 1515 GPC with THF as a mobile
phase at a flow rate of 1 mLminÀ1 and with a column temperature
of 308C. SEM images were recorded on a Hitachi S-4700 scanning
electron microscope. Thermogravimetric analysis (TGA) was con-
ducted on a TA Instruments Dynamic TGA 2950 at a heating rate
of 108C minÀ1 and under an N2 flow rate of 50 mLminÀ1. Differen-
tial scanning calorimetry (DSC) analysis was performed on a Shi-
madzu DSC 860A 85 instrument. UV/Vis absorption spectra were
determined on a Shimadzu RF540 spectrophotometer. Room-tem-
perature emission spectra were recorded using an Edinburgh-920
fluorescence spectrophotometer. Atomic force microscopy (AFM)
measurements were performed by using a Dimension Icon. Cyclic
voltammetry (CV) was performed at room temperature using an
ITO working electrode, a reference electrode Ag/AgCl, and a coun-
ter electrode (Pt wire) at a sweep rate of 100 mVsÀ1 (PGSTAT302N
Electrochemical Workstation analyzer). All electrical measurements
of the devices were characterized under ambient conditions with-
out any encapsulation using an Agilent Technologies B1500A semi-
conductor device analyzer equipped with a TTPX low and variable
temperature probe station.
2-(9H-Carbazole-9-yl)ethyl methacrylate (MCz): Methacryloyl chlo-
ride (7.95 g, 40.0 mmol) was added dropwise to a solution of Cz
(4.00 g, 19.0 mmol) in chloroform (50 mL) and triethylamine (Et3N)
(7.60 g, 75.0 mmol) at 0–58C and reacted for 12 h. The crude prod-
uct was isolated by evaporating the solvent and was purified twice
1
by recrystallization from 95% alcohol. Yield: 4.34 g, 82.1%. H NMR
(400 MHz, [D6]DMSO): d=8.15 (d, J=7.7 Hz, 2H), 7.66 (d, J=8.2 Hz,
2H), 7.46 (t, J=7.7 Hz, 2H), 7.21 (t, J=7.5 Hz, 2H), 5.74 (s, 1H),
5.53–5.50 (m, 1H), 4.75 (t, J=5.0 Hz, 2H), 4.48 (t, J=4.9 Hz, 2H),
1.65 ppm (s, 3H); 13C NMR (400 MHz, [D6]DMSO): d=167.02,
140.80, 136.03, 126.71, 126.28, 122.83, 120.88, 119.61, 110.08, 63.52,
41.84, 18.45 ppm.
Synthesis of the initiator (IN)
The synthetic procedure for the initiator IN is detailed in Scheme 1.
6-Bromo-2-dodecyl-1H-benzo[de]isoquinoline-1,3-(2H)-dione
(BrDBO): 4-Bromo-1,8-naphthalic anhydride (2.76 g, 10 mmol) and
dodecylamine (2.78 g, 15 mmol) were dissolved in ethanol
(100 mL). The reaction mixture was stirred and heated at reflux for
24 h. The resulting mixture was filtered and the resulting solid was
1
recrystallized from ethanol. Yield: 2.66 g, 61.4%. H NMR (400 MHz,
[D6]DMSO): d=8.53 (dd, J=11.9, 7.9 Hz, 2H), 8.30 (d, J=7.8 Hz,
1H), 8.19 (d, J=7.8 Hz, 1H), 7.97 (t, J=7.9 Hz, 1H), 4.01 (t, J=
7.2 Hz, 2H), 1.62 (dd, J=8.9, 4.6 Hz, 2H), 1.32–1.17 (m, 18H),
0.84 ppm (t, J=6.6 Hz, 3H).
Fabrication of devices
The schematic diagram of the fabricated memory devices is shown
in Figure 5a. The indium tin oxide (ITO)/glass (ITO: approximately
200 nm, see Figure S9a) was precleaned by sonication, with deion-
ized water, acetone, and ethanol for 15 min each. Samples
(10 mgmLÀ1) of PMCz, PMCz-IN, and PMCz+IN (PMCz blended
with approximately 1.0 wt% IN) shown in Scheme 1 in 1,2-dichloro-
ethane were prepared and filtered through microfilters with a pin-
hole size of 0.22 mm, after this the solution was spin-coated onto
the ITO/glass substrate at a rotational speed of 1500 rpm for 20 s.
These films were annealed at 908C in a vacuum oven for 12 h; the
films had a thickness of about 70–90 nm measured by SEM (shown
in Figure S9b–d). Finally, Al was thermally evaporated onto the film
surface at 510À4 Pa through a shadow mask to yield top electro-
des with a thickness of approximately 150 nm. The active area of
the fabricated device was 0.126 mm2 (a nummular point with
a radius of 0.2 mm). Thus, the three memory devices ITO/PMCz/Al,
ITO/PMCz-IN/Al, and ITO/PMCz+IN/Al were fabricated by the
above method. Herein, we focused on the investigation of the two
devices ITO/PMCz-IN/Al and ITO/PMCz+IN/Al.
2-Dodecyl-6-hydrazinyl-1H-benzo[de]isoquinoline-1,3-(2H)-dione
(DHBO): BrDBO (4.43 g, 10 mmol) and 85% hydrazine hydrate
(2.0 mL) were dissolved in 2-methoxyethanol (20 mL). The reaction
mixture was stirred and heated at reflux for 4 h. Then, the powder
was collected by filtration and washed with chloroform. Yield:
1
3.08 g, 78.0%. H NMR (400 MHz, [D6]DMSO): d=9.13 (s, 1H), 8.60
(d, J=8.4 Hz, 1H), 8.40 (d, J=7.3 Hz, 1H), 8.28 (d, J=8.6 Hz, 1H),
7.62 (t, J=7.9 Hz, 1H), 7.24 (d, J=8.6 Hz, 1H), 4.68 (s, 2H), 3.99 (t,
J=7.2 Hz, 2H), 1.62–1.54 (m, 2H), 1.31–1.19 (m, 18H), 0.84 ppm (t,
J=6.5 Hz, 3H).
3-(4-Hydroxyphenyl)-1-(4-nitrophenyl)prop-2-en-1-one (HNPE): 4-
Hydroxybenzaldehyde (2.44 g, 20 mmol), 4’-nitroacetophenone
(3.30 g, 20 mmol), and sulfuric acid (2 mL) were dissolved in acetic
acid (60 mL). The reaction mixture was stirred and heated at reflux
for 24 h. The resulting mixture was poured into a water/ice bath.
The white solid was obtained after filtering and was dried under
vacuum. Yield: 4.57 g, 85.0%. 1H NMR (400 MHz, [D6]DMSO): d=
10.20 (s, 1H), 8.35 (q, J=8.7 Hz, 4H), 7.80–7.73 (m, 4H), 6.86 ppm
(d, J=8.3 Hz, 2H).
Synthesis of the monomer (MCz)
2-Dodecyl-6-[5-(4-hydroxyphenyl)-3-(4-nitrophenyl)-4,5-dihydro-1H-
2-(9H-Carbazole-9-yl)ethanol (Cz): A mixture of carbazole (4.17 g,
25.0 mmol) and potassium hydroxide (2.10 g, 37.5 mmol) in N,N-di-
methylformamide (DMF) (50 mL) was stirred for 1 h and chloroe-
thanol (2.95 g, 37.5 mmol) was added dropwise. After stirring for
12 h at room temperature, the mixture was poured into deionized
water (500 mL) and the resultant white precipitate was removed
by filtration. The reactant was dissolved in aqueous alcohol
(70vol%, 20 mL) and insoluble matter was removed by filtration.
The filtrate was poured into deionized water (100 mL), and the
white flocculent precipitate was removed by filtration and dried
pyrazol-1-yl]-1H-benzo[de]isoquinoline-1,3-(2H)-dione
(DHHB):
HNPE (1.35 g, 5 mmol), DHBO (1.97 g, 5 mmol), and hydrochloric
acid (2.00 mL) were dissolved in ethanol (45 mL). The reaction mix-
ture was stirred and heated at reflux for 24 h. Then, the powder
was collected by filtration and washed with cooled ethanol. Yield:
1
2.65 g, 82.0%. H NMR (400 MHz, [D6]DMSO): d=9.51 (d, J=8.6 Hz,
1H), 9.45 (s, 1H), 8.49 (d, J=7.2 Hz, 1H), 8.30 (d, J=8.5 Hz, 2H),
8.21 (d, J=8.3 Hz, 1H), 8.04 (d, J=8.5 Hz, 2H), 7.83 (t, J=7.9 Hz,
1H), 7.21 (d, J=8.2 Hz, 2H), 7.13 (d, J=8.5 Hz, 1H), 6.67 (d, J=
8.3 Hz, 2H), 6.03–5.95 (m, 1H), 4.07–3.99 (m, 1H), 3.96 (d, J=
8.0 Hz, 2H), 3.30 (d, J=7.5 Hz, 1H), 1.57 (s, 2H), 1.23 (d, J=27.1 Hz,
18H), 0.83 ppm (t, J=6.4 Hz, 3H).
1
under vacuum. Yield: 4.01 g, 75.4%. H NMR (400 MHz, [D6]DMSO):
d=3.74–3.85 (m, 2H), 4.45 (dd, J=4.41, 7.07 Hz, 2H), 5.51 (t, J=
ChemPlusChem 2015, 80, 1354 – 1362
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