Paper
Journal of Materials Chemistry C
(CDCl3, 400 MHz): d ¼ 12.93 (s, 1H, Ar–OH), 10.98 (s, 1H, >C]
N–NH–(C]O)–), 8.32 (d, 1H, J ¼ 6.7 Hz, Ar–H), 7.49 (t, 1H, J ¼
7.7 Hz, Ar–H), 7.42 (d, 1H, J ¼ 7.9 Hz, Ar–H), 7.26 (t, 1H, J ¼ 7.4
Hz, Ar–H), 7.12 (t, 1H, J ¼ 7.3 Hz, Ar–H), 7.02 (d, 2H, J ¼ 7.1 Hz,
Ar–H), 6.84 (t, 1H, J ¼ 7.4 Hz, Ar–H), 4.08 (s, 3H, –OCH3), 2.34 (s,
3H, Ar–C(CH3)]N–) ppm. HRMS (APCI) calcd for C16H17N2O3
[M + H]+: m/z 285.1239. Found: m/z 285.1240.
Synthesis of alkoxysilane-modied 1,3-diketone$BF2
complex (1)
Dry triethylamine (0.25 mL, 1.8 mmol) was added to a solution
of 6 (0.181 g, 0.50 mmol) in THF (10 mL), followed by addition
of 3-isocyanatopropyltriethoxysilane (0.39 mL, 1.5 mmol). The
solution was stirred under reux for 12 h, and then cooled at
room temperature and the solvent was evaporated in vacuo. The
resulting solid was puried by silica gel column chromatog-
raphy with CHCl3/acetone (95/5) as an eluent and recrystalli-
Synthesis of 8
1
Lead tetraacetate (5.47 g, 16.8 mmol) was added to a solution of
7 (3.41 g, 12 mmol) in dry THF (100 mL) in small portions over a
period of 5 min. Aer stirring at room temperature for 3 h, the
resulting solid was removed by ltration. The ltrate was
concentrated by a rotary evaporator and puried by silica gel
column chromatography (CHCl3) to give 8 (2.86 g, 94%). 1H
NMR (CDCl3, 400 MHz): d ¼ 7.66 (d, 2H, J ¼ 6.7 Hz, Ar–H), 7.51
(m, 3H, Ar–H), 7.37 (d, 1H, J ¼ 6.7 Hz, Ar–H), 7.03 (t, 1H, J ¼ 7.5
Hz, Ar–H), 6.94 (t, 1H, J ¼ 8.5 Hz, Ar–H), 3.64 (s, 3H, –OCH3),
2.49 (s, 3H, Ar–(C]O)–CH3) ppm. HRMS (APCI) calcd for
zation from acetone/hexane to give 1 (0.090 g, 30%). H NMR
(CDCl3, 400 MHz): d ¼ 8.14–8.11 (m, 4H, Ar–H), 7.05–7.01 (m,
5H, Ar–H, –(C]O)–CH]C(–O)–), 5.05 (s, 1H, –(C]O)–(N–H)–),
4.46 (t, 2H, J ¼ 4.4 Hz, –(C]O)–OCH2–), 4.27 (t, 2H, J ¼ 4.4 Hz,
Ar–OCH2–), 3.93 (s, 3H, –OCH3), 3.82 (q, 6H, J ¼ 7.1 Hz, Si–
OCH2CH3), 3.21 (m, 2H, –(C]O)–(N–H)–CH2–), 1.64 (m, 2H, Si–
CH2CH2CH2–), 1.22 (t, 4H, J ¼ 4.4 Hz, Si–OCH2CH3), 1.22 (t, 4H,
J ¼ 4.4 Hz, Si–CH2–), ppm. 13C NMR (CDCl3, 100 MHz): d ¼
180.9, 180.6, 167.2, 165.3, 156.1, 131.2, 131.1, 124.8, 124.4,
115.0, 114.5, 91.5, 68.8, 62.6, 58.4, 55.7, 43.4, 23.2, 18.2, 7.6
ppm. 11B NMR (CDCl3, 128 MHz): d ¼ 0.88 ppm. HRMS (EI)
calcd for C28H38BF2N2O5Si [M]+: m/z 609.2377. Found: m/z
609.2401. Anal. calcd for C28H38BF2N2O5Si: C, 55.18; H, 6.28; N,
2.30. Found: C, 54.44; H, 6.07; N, 2.35%.
C
16H15O3 [M + H]+: m/z 255.1021. Found: m/z 255.1021.
Synthesis of di(iso)indomethene ligand (9)
Concentrated NH4OH (NH3 content 28–30%, 45 mL) was added
to a solution of 8 (2.75 g, 10.8 mmol) in methanol (150 mL) and
acetic acid (75 mL). The mixture was stirred at 50 ꢀC for 2 days,
and the resulting solid was collected by ltration to yield a crude
product. The crude product was puried by silica gel column
chromatography with hexane/CHCl3 ¼ 1/1 as an eluent to give 9
(1.52 g, 62%). 1H NMR (CDCl3, 400 MHz): d ¼ 7.94 (d, 4H, J ¼ 5.7
Hz, Ar–H), 7.84 (d, 2H, J ¼ 7.7 Hz, Ar–H), 7.61 (s, 1H, Ar–CH]),
7.35 (m, 4H, Ar–H), 7.24 (m, 4H, Ar–H), 7.11 (t, 2H, J ¼ 7.2 Hz,
Ar–H), 7.84 (d, 2H, J ¼ 8.5 Hz, Ar–H), 3.76 (s, 3H, –OCH3) ppm.
HRMS (APCI) calcd for C31H25 N2O2 [M + H]+: m/z 457.1916.
Found: m/z 457.1906.
Synthesis of boron di(iso)indomethene dye
Red light-emitting boron di(iso)indomethene dye
synthesized as shown in Scheme 3.
3 was
Synthesis of 7
A solution of o-hydroxyacetophenone (4.08 g, 30 mmol) and 2-
methoxybenzhydraꢀzide (7.48 g, 45 mmol) in 1-propanol (40 mL)
was stirred at 110 C for 12 h. Aer cooling to room tempera-
ture, the resulting solid is collected by ltration, washed with 1-
propanol, and then dried to give 7 (8.53 g, 97%). The obtained 7
was used for the next reaction without purication. 1H NMR
Synthesis of boron di(iso)indomethene dye (3)
Dry triethylamine (1.71 mL, 12.3 mmol) was added to a solution
of 9 (0.562 g, 1.23 mmol) in CH2Cl2 (500 mL), followed by
addition of BF3$OEt2 (3.04 mL, 24.6 mmol). The reaction
mixture was stirred at 50 ꢀC for 16 h, and then washed with
water. The organic layer was separated, dried over anhydrous
magnesium sulfate, and concentrated by a rotary evaporator to
give a blue solid. The crude product was puried by silica gel
column chromatography (CHCl3) to afford 3 (0.50 g, 81%) as a
1
metallic red-brown solid. H NMR (CDCl3, 400 MHz): d ¼ 7.89
(m, 2H, Ar–H), 7.82 (d, 1H, J ¼ 2.4 Hz, Ar–H), 7.66 (d, 1H, J ¼ 7.5
Hz, Ar–H), 7.54 (d, 1H, J ¼ 6.6 Hz, Ar–H), 7.44–7.39 (m, 4H, Ar–
H), 7.36–7.33 (m, 2H, Ar–H), 7.27 (m, 1H), 7.17 (m, 2H), 7.08–
6.96 (m, 4H), 3.76 and 3.68 (s ꢁ 2, 6H) ppm. 13C NMR (CDCl3,
100 MHz): d ¼ 157.7, 133.8, 132.5, 132.1, 132.0, 131.1, 130.9,
128.6, 127.4, 124.5, 124.4, 123.7, 123.6, 120.4, 120.2, 120.1,
118.8, 115.0, 111.2, 111.0, 55.8, 55.6 ppm. 11B NMR (CDCl3, 128
MHz): d ¼ 1.37 (t, J ¼ 37.6, 25.0 Hz) ppm. HRMS (EI) Calcd for
C
31H23BF2N2O2 [M]+: m/z 504.1821. Found: m/z 504.1816. Anal.
calcd for C31H23BF2N2O2: C, 73.83; H, 4.60; N, 5.55. Found: C,
72.01; H, 4.67; N, 5.24%.
Scheme 3 Synthesis of boron di(iso)indomethene dye 3.
This journal is ª The Royal Society of Chemistry 2013
J. Mater. Chem. C