Page 5 of 33
The Journal of Physical Chemistry
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EXPERIMENTAL SECTION
Material and Synthesis:
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All manipulations were carried out under an atmosphere of nitrogen. Acetonitrile was dried over
K2CO3 and distilled immediately before use.
1ꢀdodecyloxiꢀ4ꢀnitrobenzeno (1): To a solution containing 886.3 mg (6.38 mmol) of nitrophenol
and 5.28 g (38.28 mmol) K2CO3 in 20 ml acetonitrile under stirring was added 1.85 ml (7.66 mmol)
dodecyl bromide in 10 ml acetonitrile. The reaction mixture was refluxed for 27 hours and
subsequently filtered through Celite. The solvent was removed by reduced pressure and the crude
product was obtained as a solid. This solid was further purified by column chromatography on
neutral aluminum oxide (hexane: diethyl ether) and 1 was recovered as a white solid in 90% yield.
1H NMR (CDCl3, 300 MHz) δ (ppm): 0.88 (t, 3H, J3= 6.9 Hz, CH3), 1.27ꢀ1.47(m, 18H, CH2), 1.82
(m, 2H, CH2), 4.05 (t, 2H, J3= 6.0 Hz, OCH2), 6.93 (d, 2H, J3= 9.0 Hz, ArꢀH), 8.19 (d, 2H, J3= 9.0
Hz, ArꢀH). 13CꢀNMR (CDCl3) δ (ppm): 14.07 (CH3), 22.67, 25.91, 28.98, 29.29, 29.32, 29.52,
29.56, 29.62, 29.63, 31.91 (CH2), 68.93 (OCH2), 114.41, 125.8, 141.4, 164.26 (ArꢀC).
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4ꢀdodecyloxiꢀaniline (2): To a solution of 300.0 mg (0.98 mmol) 1ꢀdodecyloxyꢀ4ꢀnitrobenzeno (1)
dissolved in 10 ml anhydrous CHCl3 was added 8.6 ml methanol. The reaction was stirred in the
presence of 50.0 mg of 10% Pd/C under hydrogen atmosphere for 4ꢀ6 hours at room temperature.
Then, it was filtered off and the solvent was removed under reduced pressure with quantitative
yield. The bright grey solid (2) was used without further purification in the following step.
4ꢀdodecyloxyꢀ4’ꢀhydroxyl azobenzene (3): To 271.5 mg (0.98 mmol) of (2) in 4.50 ml of 1:1
aqueous acetone was added 0.45 ml of hydrochloric acid concentrated. To this mixture 2.25 mL of
aqueous NaNO2 (93.15 mg, 1.35 mmol) was added and the solution was maintained at 0ºC for 1 h.
The resulting diazonium slurry was then added to the following mixture: phenol 131.6 mg (1.40
mmol), NaOH 52.9 mg (1.32 mmol), Na2CO3 229.0 mg (2.16 mmol) in 3.80 ml of MilliQ water
maintaining the temperature at 0ºC for an additional 1 h. Then, the mixture was stirred for further
16 h at room temperature. After this, it was neutralized with acetic acid and the precipitate
containing compound (3) was well washed with MilliQ water. Further purification was not
necessary, 40% yield (mp 96ꢀ97 ºC). 1H NMR (CDCl3, 300 MHz) δ (ppm): 0.88 (t, 3H, J3= 6.9 Hz,
CH3), 1.27ꢀ1.47 (m, 18H, CH2), 1.81 (m, 2H, CH2), 4.03 (t, 2H, J3= 6.0 Hz, OCH2), 4.63 (s, 1H,
OH), 6.93 (d, 2H, J3 = 9 Hz, ArꢀH), 6.98 (d, 2H, J3 = 9 Hz, ArꢀH), 7.81 (d, 2H, J3 = 9 Hz, ArꢀH),
7.85 (d, 2H, J3 = 9 Hz, ArꢀH). 13CꢀNMR (CDCl3) δ (ppm): 14.07 (CH3), 22.67, 26.025, 29.22,
29.33, 29.38, 29.56, 29.58, 29.62, 29.65, 31.91 (CH2), 68.40 (OCH2), 114.72, 115.76, 124.33,
124.51, 146.91, 147.23, 161.27 (ArꢀC).
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