Chiral J-Aggregates of Atropo-Enantiomeric Perylene Bisimides
FULL PAPER
Synthesis of PBI 2: A portion of 1.47 g (2.0 mmol) of N,N’-bis(a-methyl-
benzyl)-1,6,7,12-tetrachloroperylene-3,4:9,10-tetracarboxylic acid bis-
ACHTUNGTRENNUNGimide (PBI 1), 410 mg (2.2 mmol) of 2,2’-biphenol and 304 mg
vent, the product was dried under vacuum (708C, 10ꢁ3 mbar, SiO2) to
obtain 64 mg (82% yield) of pure PBI 4. 1H NMR (c=45 mm, 600 MHz,
CDCl3): d=8.75 (s, 1H), 8.60 (s, 1H), 8.54 (s, 1H), 8.22 (s, 1H), 8.12 (s,
1H), 7.79 (s, 1H), 7.60 (d, J=7.7 Hz, 1H), 7.54 (t, J=7.7 Hz, 1H), 7.47
(t, J=7.6 Hz, 1H), 7.37 (d, J=7.8 Hz, 1H), 7.34 (d, J=7.7 Hz, 1H), 7.03
(m, 4H), 6.90 (t, J=7.5 Hz, 1H), 6.83 (d, J=8.4 Hz, 2H), 6.79 (t, J=
7.8 Hz, 1H), 6.75 (d, J=8.6 Hz, 2H), 6.28 (d, J=8.2 Hz, 1H), 2.54 (m,
4H), 1.57 (m, 4H), 1.32 (m, 20H), 0.90 ppm (m, 6H); 13C NMR
(100 MHz, CDCl3): d=163.14, 163.04, 162.93, 162.87, 156.37, 156.33,
156.12, 154.17, 153.07, 152.95, 152.71, 151.19, 139.66, 133.7, 131.76, 131.27,
130.88, 129.92, 129.86, 128.75, 128.12, 126.24, 125.47, 125.2, 123.1, 123.02,
122.6, 122.48, 122.01, 121.86, 121.67, 120.99, 120.75, 120.51, 120.23, 120.17,
119.92, 119.76, 119.63, 118.95, 116.62, 35.42, 32.08, 31.72, 31.7, 29.65,
29.51, 29.46, 22.84, 14.26 ppm; UV/Vis (CHCl3): lmax (emax)=574 (44 000),
532 (25 500), 456 nm (14 600mꢁ1 cmꢁ1); fluorescence: lmax (CHCl3, 258C,
lex =530 nm)=596 nm, FFl (CHCl3, 258C)=0.94ꢀ0.01, lmax (MCH,
608C)=568 nm, FFl (MCH, 608C, lex =530 nm)=1.00ꢀ0.01; HRMS
(ESI, CHCl3/acetonitrile 1:1, pos. mode): m/z calcd for C64H57N2O8,
981.4115 [M+H]+; found: 981.4107.
(2.2 mmol) K2CO3 were suspended in 80 mL of N-methyl-2-pyrrolidone
(NMP) and stirred under argon at 1208C for 40 h. After being cooled to
room temperature, the reaction mixture was dropped into 300 mL of 1 N
HCl under stirring. The precipitate was separated by filtration and
washed successively with water (3ꢃ50 mL) and methanol (3ꢃ50 mL).
The crude product was purified by column chromatography on silica gel
using CH2Cl2/n-hexane (70:30) as an eluent. After removal of the solvent
with rotary evaporator, 730 mg (44% yield) of PBI 2 were obtained.
1H NMR (400 MHz, CDCl3): d=8.66–8.60 (m, 2H), 8.50–8.46 (m, 1H),
7.83 (m, 1H), 7.60–7.20 (m, 15H), 6.88 (m, 1H), 6.77 (m, 1H), 6.58 (q,
J=7.3 Hz, 1H), 6.41 (q, J=7.1 Hz, 1H), 6.20 (m, 1H), 2.03 (dd, 3H),
1.92 ppm (d, 3H); 13C NMR (100 MHz, CD2Cl2): d=162.1, 162.0, 161.95,
161.88, 161.78, 161.74, 161.7, 161.62, 155.55, 153.71, 151.83, 151.82, 150.15,
139.93, 139.78, 139.73, 134.03, 133.97, 131.89, 131.26, 131.21, 130.58,
130.53, 130.41, 130.36, 130.08, 129.83, 129.82, 129.23, 129.19, 129.0, 128.86,
128.39, 127.51, 127.5, 127.49, 127.36, 127.33, 127.29, 127.24, 126.27, 126.25,
126.17, 126.11, 125.46, 124.33, 124.28, 123.05, 122.71, 122.68, 122.55, 122.1,
120.91, 120.26, 119.72, 119.68, 119.6, 119.57, 118.31, 118.25, 115.95, 49.82,
49.76, 49.72, 15.36, 15.27, 15.25, 15.17 ppm; UV/Vis (CHCl3): lmax (emax)=
Resolution of atropo-enantiomers (P-4 and M-4) by HPLC: Separation
of the enantiomers was achieved on a semi-preparative column (Trentec
Reprosil 100 chiral-NR, Ø=2.5 cm) using chloroform as an eluent (flow:
8.0 mLminꢁ1). The retention times for the first and second eluted atropo-
enantiomers are 17 min and 25 min, respectively.
549 nm (40 000m ꢁ1 cmꢁ1); fluorescence (CHCl3, lex =530 nm): lmax
=
571 nm, FFl =0.86ꢀ0.01; HRMS (ESI, CHCl3/acetonitrile 1:1, pos.
mode): m/z calcd for C52H31Cl2N2O6, 849.1559 [M+H]+; found: 849.1551.
Preparation of aggregates in methylcyclohexane (MCH): The aggregates
of both enantiopure and racemic PBI 4 were prepared by injecting the
concentrated chloroform solutions (3.8ꢃ10ꢁ3 m) into MCH, followed by
ultrasonic treatment for half a minute to give a homogenous mixture.
The aggregates in MCH with different concentrations were kept at room
temperature in 5 mL vials overnight to reach the equilibrium between
the monomers and aggregates. Then the samples were shaken for about
10 seconds and then transferred into quartz cells for UV/Vis absorption
and fluorescence measurements. For AFM measurements, the aggregates
prepared in MCH with a concentration of about 5ꢃ10ꢁ5 m was shaken for
about 10 seconds and then drop-cast onto muscovite mica or Si-wafer
(SiOx) surfaces. After approximately 30 seconds, the solvent was removed
by spinning for one minute (7000 rminꢁ1).
Synthesis of PBI 3: A portion of 255 mg (0.30 mmol) of PBI 2, 186 mg
(0.90 mmol) of 4-tert-butylphenol and 62.2 mg (0.45 mmol) of K2CO3
were suspended in 10 mL of NMP and stirred under argon at 1208C for
24 h. After being cooled to room temperature, the reaction mixture was
dropped into 100 mL NaCl(aq), then extracted with CHCl3 (2ꢃ50 mL).
The organic layer was washed with water (3ꢃ100 mL), and dried over
Na2SO4. The crude product was purified by column chromatography on
silica gel using CH2Cl2/n-hexane (60:40) as an eluent. After removing the
solvent with rotary evaporator, 150 mg (42% yield) of PBI 3 was ob-
tained. 1H NMR (400 MHz, CD2Cl2): d=8.44 (m, 1H), 8.01 (m, 1H),
7.88 (m, 1H), 7.64 (m, 1H), 7.51 (m, 1H), 7.44 (m, 1H), 7.40–7.32 (m,
3H), 7.31–7.02 (m, 10H), 6.95 (m, 4H), 6.80 (m, 1H), 6.75–6.65 (m, 5H),
6.40 (q, J=6.8 Hz, 1H), 6.21 (m, 2H), 2.45 (m, 4H), 1.86 (d, 3H), 1.73
(d, 3H), 1.47 (brs, 4H), 1.24 (m, 20H), 0.81 ppm (m, 4H); 13C NMR
(100 MHz, CD2Cl2): d=163.71, 163.59, 163.56, 163.48, 163.41, 163.37,
163.32, 163.22, 156.64, 156.54, 156.27, 154.51, 154.49, 153.65, 153.62,
153.58, 153.49, 153.47, 153.43, 153.41, 153.27, 151.62, 141.4, 141.35, 141.24,
141.16, 139.9, 139.89, 133.59, 133.57, 131.66, 131.62, 131.57, 131.51, 131.07,
130.12, 130.06, 128.96, 128.57, 128.54, 128.45, 128.41, 128.39, 128.32,
127.38, 127.25, 127.18, 126.33, 125.78, 125.22, 125.18, 123.89, 123.84,
123.41, 123.36, 123.32, 123.29, 122.16, 121.63, 121.59, 121.27, 120.85,
120.72, 120.7, 120.63, 120.61, 120.53, 120.48, 120.28, 120.26, 120.19, 120.08,
119.91, 119.81, 119.45, 119.34, 119.31, 116.97, 50.63, 50.61, 50.57, 50.52,
35.61, 32.35, 32.03, 29.89, 29.76, 29.72, 23.11, 16.46, 16.39, 16.33, 16.28,
14.29 ppm; UV/Vis (CHCl3): lmax (emax)=576 nm (51 300mꢁ1 cmꢁ1); fluo-
rescence (CHCl3, lex =530 nm): lmax =597 nm, FFl =0.94ꢀ0.01; HRMS
(ESI, CHCl3/acetonitrile 1:1, pos. mode): m/z calcd for C80H73N2O8,
1189.5367 [M+H]+; found: 1189.5378.
Acknowledgements
We thank the Alexander von Humboldt Foundation for a postdoctoral
fellowship for Z.X.
[1] For reviews, see: a) J-Aggregates, (Ed: T. Kobayashi), World Scien-
tific, Singapore, 1996; b) D. Mçbius, Adv. Mater. 1995, 7, 437–444;
853; d) S. Kirstein, S. Dꢁhne, Int. J. Photoenergy 2006, 5, 3; e) F. C.
[2] a) K. E. Achyuthan, T. S. Bergstedt, L. Chen, R. M. Jones, S. Kumar-
aswamy, S. A. Kushon, K. D. Ley, L. Lu, D. McBranch, H. Mukun-
[3] D. M. Eisele, H. V. Berlepsch, C. Bçttcher, K. J. Stevenson, D. A.
[4] a) E. Lang, A. Sorokin, M. Drechsler, Y. V. Malyukin, J. Kçhler,
Synthesis of the target PBI 4: A mixture of 95 mg (0.08 mmol) of PBI 3
and 1.0 g (18.0 mmol) of solid KOH in 15 mL of tBuOH was heated to
808C for 3 h. After being cooled to room temperature, the reaction mix-
ture was dropped into 50 mL glacial acetic acid under stirring. Then
200 mL water was added to dilute the mixture. The crude product was
extracted with 50 mL CHCl3, and then the organic layer was separated
and washed successively with water (100 mL), NaHCO3 (aq) (100 mL),
and again water (2ꢃ100 mL). The chloroform solution was dried over
Na2SO4 and the solvent was removed with rotary evaporator. The residu-
al solid was dissolved in 20 mL propionic acid together with 2.0 g of am-
monium acetate. The mixture was stirred at 1408C for 60 h. After cooling
to room temperature, the mixture was added dropwise into 200 mL water
under stirring. The crude product was extracted with chloroform (2ꢃ
50 mL) and the organic solution was dried over MgSO4. After removing
the solvent, the residue was purified by column chromatography on silica
gel using chloroform as an eluent. After rotatory evaporation of the sol-
Chem. Eur. J. 2012, 00, 0 – 0
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