E.O. Dare et al.
Dyes and Pigments 184 (2021) 108841
commercially available reagents and solvents were used without further
purification.
hydrochloric acid, water and methanol before charging it into a 500 mL
flask, which was equipped with a magnetic stirrer. Methanol (150 mL)
was added and stirred at 30 ◦C. Vinyltrichlorosilane (4.0 mL, 0.04 mol)
was added slowly with stirring to the Amberlite methanolic solution.
The stirring continued at room temperature for 10 h during which white
microcrystals were deposited on the wall of the flask. Methanol was
decanted into a pre-prepared 500 mL flask (to be reused in the next
experiment). Dichloromethane was added to dissolve the microcrystals
and the amberlite was filtered out for reuse in subsequent experiments.
The solvent was evaporated and the vinyl-T8 microcrystals washed
several times with methanol.
2.2. Synthesis and characterization of compounds
Synthesis of alkynyl dansyl derivative: 5-(dimethylamino)-N-(2-
propynyl)-1-naphthalenesulfonamide (N-dansyl propynyl, D) was pre-
pared according to previous procedure. [15] 1H and 13C NMR spectral
data for D were found to be similar to those found in literature.
Synthesis of octakis (3-chloropropyl)octasilsesquioxane (POSS-Cl):
[16] A solution of dry methanol (150 mL) and concentrated hydro-
chloric acid (5 mL) was placed in a two-necked, round-bottomed flask
equipped with a condenser, an addition funnel, and a magnetic stir bar.
To this solution was added dropwise a portion of (3-chloropropyl)tri-
methoxysilane (15 g, 0.075 mol) through the addition funnel over a
period of 10 min with vigorous stirring. The stirring was continued for 2
h until the solution had cooled to room temperature. The reaction
mixture was kept at room temperature for another 48 h without stirring.
After 2 days, di-n-butyltin dilaurate (0.15 g, 0.24 mmol), as a conden-
sation catalyst, was added with stirring. The reaction mixture was
maintained at room temperature for 2 days until a white crystalline
precipitate appeared. The solution was filtered, and the crystals were
collected, washed several times with methanol, and dried under vac-
uum. Spectra results were in accordance with previously reported data.
[16]
1H NMR (CDCl3) δ (ppm): 5.69–6.15 (m, H2C=CH–, 24H); 13C NMR
(CDCl3) δ (ppm): 128.70 (C1), 136.95 (C2); 29Si NMR (CDCl3) δ (ppm):
ꢀ 79.8, ꢀ 80.6 (–SiCH=CH2).
Synthesis of POSS-S-Cl: POSS-vinyl (2.0 g, 3.16 × 10ꢀ 3 mol) was
dissolved in anhydrous toluene (15 mL) under N2 atmosphere. The
radical initiator AIBN (0.2 g, 1.22 × 10ꢀ 3 mol) was added to POSS-Vinyl
solution and the reaction mixture was heated to 40 ◦C. Then the linker 3-
chloropropanethiol (2.64 mL, 27 × 10ꢀ 3 mol) was slowly added to the
mixture and the reaction was stirred for 13 h at 60 ◦C. After cooling the
reaction at room temperature, the supernatant was removed, and the gel
was solubilized in dichloromethane (5.0 mL) and precipitated with
◦
hexane (5 × 50 mL) at 0 C. Finally, the gel was dried under reduced
pressure to give the desired product as transparent viscous gel (1.97 g,
yield 99%).
1H NMR (300 MHz, CDCl3) δ (ppm): 1.08 (m, 16H, -SiCH2-); 2.1 (m,
16H, -SCH2CH2-); 2.63 (overlapped, 16H, -SCH2-); 2.65 (overlapped,
16H, SiCH2CH2-S-); 3.71 (t, 16H, J = 6.3, -CH2Cl). 13C NMR (100 MHz,
CDCl3) δ (ppm): 42.5, 32.6, 29.8, 26.3, 14.1.29Si NMR (99 MHz) δ (ppm):
ꢀ 68. Elemental analysis (%) for C40H80Cl8O12S8Si8, calculated: C =
31.64, H = 5.30 S = 16.91; found: C = 31.89, H = 5.28, S = 16.55.
Synthesis of POSS-S-N3. POSS-S-Cl (1.5 g, 9.9 × 10ꢀ 4 mol) and
excess of NaN3 (2.0 g) were added to a flask equipped with a magnetic
stirrer along with 15 mL of anhydrous N,N-dimethylformamide (DMF).
The reaction was carried out at 70 ◦C for 2 days. After completion of the
reaction, distilled water was added, and the mixture was extracted with
CH2Cl2. Organic layers were dried over anhydrous sodium carbonate,
filtered, and concentrated under reduced pressure to obtain the desired
product as a yellow viscose liquid (1.23 g, Yield 82%)
1H NMR (CDCl3, 298 K, 300 MHz; ppm): 0.78 (t, 16H, SiCH2); 1.84
(q, 16H, CH2); 3.53 (t, 16H, CH2Cl). 13C NMR (CDCl3, 298 K, 75.5 MHz;
ppm): 9.9 (SiCH2-); 26.4 (-CH2-); 47.1 (-CH2Cl). 29Si NMR (CDCl3, 298
K, 59.6 MHz; ppm): ꢀ 67.28.
Synthesis of octakis (3-azidopropyl)octasilsesquioxane (POSS-N3):
[17] POSS-Cl (0.935 mmol, 0.98 g) and NaN3 (2.13 g) were added to a
flask equipped with a magnetic stirrer along with 17 mL of anhydrous N,
N-dimethylformamide (DMF). The reaction was carried out at 120 ◦C for
48 h. After completion of the reaction, distilled water was added, and the
mixture was extracted with CH2Cl2. Organic layers were dried over
anhydrous sodium carbonate, filtered, and concentrated under reduced
pressure to obtain the desired product as a yellow viscose liquid. Spectra
results were in accordance with previously reported data. [17]
1H NMR (CDCl3, 500 MHz) δ (ppm): 0.71–0.74 (t, 16H, SiCH2),
1.66–1.73 (q, 16H, CH2), 3.25–3.28 (t, 16H, CH2N3). 13C NMR (CDCl3,
125 MHz) δ (ppm): 8.95 (SiCH2-), 22.42 (-CH2), 53.36 (-CH2N3). 29Si
NMR (CDCl3, 99 MHz) δ (ppm) ꢀ 67.04.
1H NMR (300 MHz, CDCl3) δ (ppm): 1.01 (m, 16H, -SiCH2-); 1.90 (m,
16H, -SCH2CH2-); 2.58 (overlapped, 16H, -SCH2-); 2.61 (overlapped,
16H, SiCH2CH2-S-); 3.43 (t, 16H, J = 6.0, -CH2Cl). 13C NMR (100 MHz,
CDCl3) δ (ppm): 41.9, 32.9, 28.8, 25.7, 13.6.29Si NMR (99 MHz) δ (ppm):
ꢀ 68. Elemental analysis (%) for C40H80N24O12S8Si8, calculated: C =
30.59, H = 5.13, N = 21.41; found: C = 30.41, H = 5.11, N = 21.44.
Synthesis of POSS-S-D8: Under nitrogen atmosphere, N-dansyl pro-
pynyl, D (2.25 g, 7.8 × 10ꢀ 3 mol) was added to 10 mL THF/DMF (1:1)
solution of POSS-S-N3 (1.23 g, 7.8 × 10ꢀ 4 mol). CuBr (50% mol
equivalent) and PMDETA (50% mol equivalent) were successively
added. The reaction mixture was stirred at RT overnight. 0.02 M EDTA
was added and extracted with DCM. Organic phase was further washed
with deionized water and Na2SO4 added. After filtration and concen-
tration in a rotary evaporator, the solid was recrystallized in chloro-
form/methanol (1:3) to give the desired product as a light yellow solid
(1.12 g, Yield 91%).
Synthesis of octakis (3-dansylpropyl)octasilsesquioxane (POSS-D8):
Under nitrogen atmosphere, to a 10 mL DMF/THF (1:1) solution of
POSS-N3 (0.1 g, 9.2 × 10-5 mol) was added N-dansyl propynyl, D (0.24
g, 8.3 × 10-4). CuBr (50% mol equivalent) and PMDETA (50% mol
equivalent) were successively added. The reaction mixture was stirred at
RT overnight. 0.02 M EDTA was added and extracted with DCM. Organic
phase was further washed with deionized water and Na2SO4 added.
After filtration and concentration in a rotary evaporator, further puri-
fication was achieved in a column chromatography (Hexane: Ethyl ac-
etate, 30%) to afford the desired product as a light yellow solid (0.078 g,
yield 78%).
1H NMR (300 MHz, CDCl3) δ (ppm): 0.61 (m, 16H, -SiCH2-), 1.81 (m,
16H, Si-CH2CH2-), 2.8 (s, 48H, -N(CH3)2), 4.24 (overlapped 16H,
-CH2N-), 4.25 (overlapped 16H, triazole-CH2NH-), 7.15 (s, 8H, -CH2NH-
) 7.7 (s, 8H, in 1,2,3-triazole), 7.3–7.5, 8.25–8.3, 8.5 (all m, 6H, CH in
dansyl aromatic); 13C NMR (125 MHz, CDCl3) δ (ppm): 102.5, 107, 116,
118, 123, 128, 131.29Si NMR (59.6 MHz, CDCl3) δ (ppm): ꢀ 67.93 (Si-O-
Si); FT-IR (cmꢀ 1): v (CH) 2932.6; (CN) 1646; (NCO) 1644.7 v (C=C-Ar)
1741.9; v (Si-O-Si) 1161-1020; MS (API-ESI) m/z: 3397.40 [M+H]+.
Elemental analysis: calculated for C144H176N40O28S8Si8 (MW 3396.40) C
45.12, H 5.80, N 18.47; found C 45.16, H 5.88, N 18.51%.
1H NMR (300 MHz, CDCl3) δ (ppm): 1.09 (br s, 16H, -SiCH2-); 2.14
(m, 16H, -SCH2CH2-); 2.49 (m, 16H, -SCH2-); 2.61 (m, 16H, SiCH2CH2-S-
); 2.85 (s, 48H, Ar-N(CH3)2); 4.15 (m, 16H, -SCH2CH2CH2-N-); 4.30 (br
s, 16H, -CH2NH); 7.1 (br s, 8H, sulfonamide proton NH). 13C NMR (100
MHz, CDCl3) δ (ppm): 15.1, 25, 38, 45.1, 52, 53.3, 66.2, 116.0, 118.6,
121, 128.4, 135.8, 151.29Si NMR (99 MHz) δ (ppm): 67. FT-IR (cmꢀ 1): v
(CH) 2966.6; (CN) 1678; (NCO) 1644.7 v (C=C-Ar) 1741.9; v (Si-O-Si)
1161-1020; MS (API-ESI) m/z: 3875.98 [M+H]+; Elemental analysis
(%) for C160H208N40O28S16Si8; calculated: C = 48.56, H = 5.41 N =
13.98; found: C = 48.39, H = 5.52, N = 13.79.
Synthesis of octavinylsilsesquioxane (POSS-vinyl): Formation of
POSS-vinyl was realized based on literature data. [18] Thus, acidic
amberlite of medium porosity (40 g) was washed with concentrated
3