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H. Eserci et al. / Journal of Molecular Structure 1182 (2019) 1e8
der Waals attraction between the individual tubes [20e23]. Espe-
cially by using evolutionary techniques to overcome these high
attractive forces, a variety of additives to support the dispersion and
individualization of CNTs by noncovalent functionalization method
have been reported [4,18,21,24,25]. Particularly nanotube disper-
sion with tailor-made molecules is still a very intriguing view, since
it displays the easiest way to disconnect CNTs. Even though poly-
mers including polyorganophosphazenes perform quite well for
individualizing nanotubes and mostly surpass monomeric
designed molecules, they show rather low carbon nanomaterial
uptake yield and, it is almost impossible to clear of the polymer
after the solubilization process [26]. Among the many non-covalent
approaches, the functionalization of aromatic compounds on CNTs
have been studied by using designed surfactant systems especially
containing perylene bisimide unit for interaction with the CNT
backbone. Perylene diimides have attracted attention for opto-
electronics especially in solar cell applications [27e29]. They
exhibit strong absorption with high extinction coefficiency in the
visible range and high electron affinity of the large band-gap ma-
terial [30,31]. Thus, ongoing material science researches of perylene
derivatives intend incorporating outstanding chemical, thermal
otherwise specified. SWCNT has been purchased from US nano-
materials inc. and used without further purification.
2.2. Equipment
Electronic absorption spectra were recorded with a Shimadzu
2101 UV spectrophotometer in the UVevisible region. Fluorescence
excitation and emission spectra were recorded on a Varian Eclipse
spectrofluorometer using 1 cm pathlength cuvettes at room tem-
perature. The fluorescence lifetimes were obtained using Horiba-
Jobin-Yvon-SPEX Fluorolog 3-2iHR instrument with Fluoro Hub-B
Single Photon Counting Controller at an excitation wavelength of
500 nm and 570 nm. Signal acquisition was performed using a
TCSPC module. Zeta potential analysis were performed on MAL-
VERN Zetasizer Nano-ZS. Elemental analyses were obtained using a
Thermo Finnigan Flash 1112 Instrument. Mass spectra were ac-
quired in linear modes with average of 50 shots on a Bruker Dal-
tonics Microflex mass spectrometer (Bremen, Germany) equipped
with a nitrogen UV-Laser operating at 337 nm. 1H, 13C and 31P NMR
spectra were recorded in CDCl3 solutions on a Varian 500 MHz
spectrometer and residual solvent signals used as the lock refer-
ence (secondary reference). Morphology of the SWCNT-5P-7P
composites were characterized using a JEOL 2100 HRTEM. The
structural analyses were performed on HORIBA Jobin-Yvon HR
800UV Raman Spectrometer. Analytical thin layer chromatography
(TLC) were performed on silica gel plates (Merck, Kieselgel 60 Å,
0.25 mm thickness) with F254 indicator. Column chromatography
were performed on silica gel (Merck, Kieselgel 60 Å, 230e400
mesh). Suction column chromatography was performed on silica
gel (Merck, Kieselgel 60 Å, 70e230 mesh).
and photochemical stabilities and properties of these p-conjugated
materials with potential devices for optoelectronics [32]. The in-
teractions and synergy between CNTs and as electron-poor poly-
aromatic system perylene, grant liable way to disperse CNTs
[28,33e36]. For instance, tailor made cyclotriphosphazene frame-
works decorated with asymmetric perylene and hydrophilic glycol
units can provide valuable useful materials for CNT based materials.
In the following, architecturally designed cyclotriphosphazene
derivatives constitute from perylene and glycol units with unique
photophyisical properties have been issued and the non-covalent
dispersion concept is extended to cyclotriphosphazene de-
3. Synthesis
rivatives with precise stereo isomer bearing perylene units for p- p
interaction and glycol moieties for hydrophilicity. For this purpose,
we have designed and synthesized a variety of novel perylene-
cyclotriphosphazene compounds decorated with triethylene gly-
col monomethyl ether moieties giving access to a comparative
study to investigate spectroscopic, dispersibility and morphological
properties of the soluble perylene-cyclotriphosphazene-SWCNT
nanocomposites. The perylene-cyclotriphosphazene compounds
are characterized with elemental analysis, 1H, 31P, 13C NMR spec-
troscopy and MALDI spectrometry. The optical, dispersibility and
Compounds 1e5 were synthesized according to the literature
(Scheme 1) [37e40].
3.1. Synthesis of compound 6
Sodium hydride (0.46 g, 0.012 mol) was added to a stirred so-
lution of trimer (1 g, 0.003 mol) dissolved in 100 mL of dry tetra-
hydrofuran (THF) under an argon atmosphere in a 250 mL three-
necked round bottomed flask and the solution was cooled down
to ꢀ78 ꢁC by a N2/acetone bath. Triethylene glycol monomethyl eter
(1.89 g, 0.012 mol) in 50 mL of dry THF was added dropwise to a
stirred solution under argon atmosphere. The reaction mixture was
stirred for 30 min at liquide N2/acetone bath and then room tem-
perature for 3 h. The reaction was followed by TLC. The precipitated
salt (NaCl) was filtered off and the solvent was removed under
reduced pressure. The crude compound 6 was subjected to column
chromatography silica gel [(70e230 mesh)] using hexane-
THFeDCM (1:1:1) as eluent.
morphological
properties
of
the
soluble
perylene-
cyclotriphosphazene- SWCNT nanocomposites have been investi-
gated by using UVe Vis absorption, fluorescence, raman spectros-
copy, zeta potential and HRTEM.
2. Experimental
2.1. Materials
The deuterated solvent (CDCl3) for NMR spectroscopy, silica gel,
hydrochloric acid, pH color strip and triethylene glycol mono-
methyl ether have been provided from Merck. Following chemicals
have been obtained from Sigma Aldrich; tetrahydrofuran, ethanol,
dichloromethane, methanol, sodium hydride, dihexyl ketone and
ammonium acetate, trans-2-[3-(4-tert-Butylphenyl)-2-methyl-2-
propenylidene]malononitrile, 2,5-Dihydroxybenzoic acid, Dithra-
nol. Natriumcyanborhydrid, perylene-3,4,9,10-tetracarboxylic dia-
nhydride, t-Butanol, N,N-dimethylacetamide and phosphonitrilic
chloride (trimer) have been purchased from Acros Organics. Po-
tassium carbonate, imidazole and zinc acetate anhydrous has been
provided from Alfa Aeasar. Methanol has been purchased from
VWR. 6-aminohexanol has been purchased from T.C.I. All other
chemicals used for the synthesis were reagent grade unless
Compound 6: Yield 0.98 g (40%). Elemental analyses: Calc. (%)
for C28H60Cl2N3O16P3: C, 39.17; H, 7.04; N, 4.89; found C, 39.09; H,
7.01; N, 4.90. 31P NMR decoupled (202 MHz, CDCl3, 298 K):
d
¼ 24.35 (d, J ¼ 79.3 Hz, 2P, P(eOCH2e)Cl), 12.22 (t, J ¼ 79.2 Hz, 1P,
P(eOCH2e)2); spin system: A2X. 1H NMR (500 MHz, CDCl3, 298 K):
¼ 4.29 (br, 4H); 4.16 (br, 4H); 3.75e3.54 (br, 40H); 3.44e3.38 (br, s,
12H). 13C NMR (126 MHz, CDCl3, 298 K):
d
d
¼ 71.93, 70.78, 70.69,
70.68, 70.62, 70.59, 70.58, 70.55, 59.03, 59.02. MS (MALDI-TOF)
(DCTB) m/z Calc.: 858.61; found: 858.83 [M]þ, 881.69 [M þ Na]þ.
3.2. Synthesis of compound 7
Sodium hydride (0.58 g, 0.014 mol) was added to a stirred so-
lution of trimer (1 g, 0.003 mol) dissolved in 100 mL of dry