S. Jiang et al.
Dyes and Pigments 163 (2019) 363–370
crystalline molecule is a good chiral-transfer candidate for constructing
organic CPL materials with excellent emission at aggregated state.
2. Experimental
2.1. General
The chemicals for synthetic procedures were obtained from Aladdin
Co. Ltd. and used directly unless indicated otherwise. TLC was carried
out on glass plates pre-coated with silica gel. Column chromatographic
separation was done on silica gel (100–200 mesh). NMR spectra were
3
measured in CDCl on a Bruker-ARX 400 spectrometer with tetra-
methylsilane (TMS) as internal standard. MS spectra were recorded by
Bruker mass spectrometer. Perkin-Elmer 2400 CHN Elemental Analyzer
was employed for elemental analyses. DSC measurements were ex-
−1
amined on Thermal Analyzer Q100 at a scanning rate of 10 °C min
under N atmosphere. Mesomorphic texture was observed under a po-
2
larization optical microscope (Leica DMRX) with a temperature-con-
trolled heating stage (Linkam THMSE 600). X-ray diffraction (XRD)
experiments were performed on
a Seifert-FPM XRD7 X-ray dif-
fractometer using Cu Kα radiation (λ = 1.5406 Å) with 40 kV, 30 mA
power. UV–vis absorption spectra were detected on a Varian spectro-
photometer. Fluorescent spectra were measured on a Hitachi F-4500
spectrometer with conventional quartz cell (10 × 10 × 45 mm) at 25 °C
(
constant-temperature water bath). The fluorescence absolute quantum
yield (Φ was examined on an Edinburgh Instruments FLS920
F
)
Fluorescence Spectrometer with a 6-inch integrating sphere. CD spectra
were recorded on a Jasco J-815 CD spectrometer (Jasco, Japan). CPL
was measured on a Jasco CPL-200 spectrometer (Jasco, Japan). The
cholesterol derivatives 2 and 3 were prepared according to literature
[
41]. Tetraphenylethylene tetrahydroxyl derivative 5, 6 and 7 were
synthesized by the reported procedures [42].
2.2. The synthetic procedure of TPE-C
The mixture of compound 5 (0.1 g, 0.25 mmol), anhydrous po-
tassium carbonate (1.0 g, 7.2 mmol) and compound 2 (0.462 g, 1 mmol)
were stirred and refluxed in 40 mL of dried acetonitrile. The reaction
was monitored by TLC analysis. After reacting for 24 h, 60 mL of 1M
HCl solution was dropped in reaction system, and the mixture was
extracted with CHCl
and concentrated. The residue was purified by column chromatography
CH Cl as eluent) to give compound TPE-C as white powder in the
yield of 78%. Compound TPE-C: H NMR (400 MHz, CDCl
3
(2 × 20 mL). The organic phase was separated
Scheme 1. The synthetic routes for TPE-C and TPE-SC.
(
2
2
1
CDCl
1
6
3
) δppm: 164.08, 155.59, 151.81, 150.28, 149.19, 138.71, 137.79,
32.77, 130.91, 125.75, 122.87, 114.00, 112.41, 110.13, 72.47, 66.74,
5.37, 56.71, 56.03, 49.95, 42.34, 39.76, 39.43, 38.09, 36.76, 36.51,
3
) δppm: 6.89
(
d, J = 8.0 Hz, 8H, ArH), 6.61 (d, J = 8.0 Hz, 8H, ArH), 5.37 (bs, 4H,
CH]C), 4.72 (bs, 4H, CH), 4.51 (s, 8H, OCH
2
), 0.67–2.39 (m, 172H,
) δppm: 168.25, 156.25,
39.27, 137.44, 132.44, 131.79, 123.00, 113.89, 75.00, 65.49, 56.71,
1
3
36.19, 35.78, 31.87, 29.64, 28.21, 27.87, 24.27, 23.72, 22.81, 22.56,
1.04, 19.32, 18.72, 11.87; MALDI-TOF-MS (C178+ 20) Calcd. for
m/z = 2806.773, found: m/z = 2807.879 (MH ). Anal. calcd. for
20: C, 76.14; H, 8.47; N, 3.99. found: C, 76.10; H, 8.44; N,
cholesterol unit); C NMR (100 MHz, CDCl
3
2
236 8
H N O
1
5
3
1
6.21, 50.03, 42.33, 39.76, 39.56, 37.99, 36.94, 36.56, 36.25, 35.85,
1.86, 29.76, 28.28, 28.02, 27.69, 24.32, 23.92, 22.88, 22.63, 21.08,
C
178 236 8
H N O
3.92.
9.33, 18.78; MALDI-TOF-MS (C142
H
204
O
12
+
)
Calcd. for m/
z = 2102.539, found: m/z = 2102.920 (M ). Anal. calcd. for
12: C, 81.09; H,9.78. found: C, 81.03; H, 9.73.
C
142
H
204
O
3. Results and discussion
2.3. The synthetic procedure of TPE-SC
3.1. Synthesis and characterization
The mixture of compound 3 (0.548 g, 1 mmol) and 7 (0.171 g,
The synthetic routes were illustrated in Scheme 1. The tetra-
phenylethylene derivative TPE-C with four cholesterol units was de-
signed as target compound. On the other hand, in order to enhance the
π-π packing abilities for columnar liquid crystalline phase, the tetra-
phenylethylene aromatic acylhydrazone derivatives TPE-SC was de-
signed as another target compound because the extended aromatic
acylhydrazone structure and the hydrogen bond of NH group were fa-
vorable for columnar mesophase. According to the literature [41], the
cholesterol derivatives 2 and 3 were prepared by using cholesterol as
starting material. Tetraphenylethylene tetrahydroxyl derivative 5 was
0
2
.25 mmol) were refluxed in 30 mL of CHCl
3
/MeOH (V/V = 4:1) for
4 h with four drops of glacial acetic acid as catalyst. After reaction, the
solvents were distilled under reduced pressure. The residue was pur-
ified by column chromatography (eluent: CH Cl /ethyl acetate = 5:1,
V/V). Compound TPE-SC was obtained as white powder in the yield of
2
2
8
4
(
4%. Compound TPE-SC: 1H NMR (400 MHz, CDCl
H, CH), 7.76 (s, 4H, NH), 7.63 (bs, 8H, ArH), 6.84 (bs, 16H, ArH), 6.62
3
) δppm: 8.31 (bs,
bs, 8H, ArH), 5.37 (bs, 4H, CH]C), 4.73 (bs, 4H, CH), 4.58 (s, 16H,
OCH
2
), 0.67–2.35 (m, 172H, cholesterol unit); 1 C NMR (100 MHz,
3
364