Supporting Information:
Structure/Reactivity/Photoinitiation Ability Relationships in
Novel Benzo Pyrazolo (or Imidazo) Isoquinolinone Derivatives
upon Visible Light LEDs.
Pu Xiao,*,a Frédéric Dumur,b Jing Zhang,a Bernadette Graff,a Jean Pierre Fouassier,1 Didier
Gigmes*,b and Jacques Lalevée*,a
All reagents and solvents were purchased from Aldrich or Alfa Aesar and used as
received without further purification. Mass spectroscopy was performed by the Spectropole of
Aix-Marseille University. ESI mass spectral analyses were recorded with a 3200 QTRAP
(Applied Biosystems SCIEX) mass spectrometer. The HRMS mass spectral analysis was
performed with a QStar Elite (Applied Biosystems SCIEX) mass spectrometer. Elemental
analyses were recorded with a Thermo Finnigan EA 1112 elemental analysis apparatus driven
by the Eager 300 software. 1H and 13C NMR spectra were determined at room temperature in
5 mm o.d. tubes on a Bruker Avance 400 spectrometer of the Spectropole: 1H (400 MHz) and
13
C (100 MHz). The 1H chemical shifts were referenced to the solvent peak CDCl3 (7.26 ppm),
DMSO (2.49 ppm) and the 13C chemical shifts were referenced to the solvent peak CDCl3 (77
ppm), DMSO (49.5 ppm). All these photoinitiators were prepared with analytical purity up to
accepted standards for new organic compounds (>98%) which was checked by high field
NMR
analysis.
3-(Hexylamino)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one
IQ1 was synthesized as previously reported [P. Xiao, F. Dumur, B. Graff, J. Zhang, F.
Morlet-Savary, D. Gigmes, J. P. Fouassier, J. Lalevée, J. Polym. Sci. A Polym. Chem. (2015)
DOI: 10.1002/pola.27477]. 5-Nitrobenzo[de]isochromene-1,3-dione [J.-J. Lee, B. C. Noll, B.
D. Smith, Org. Lett., 2008, 10, 1735–1738], 5-Aminobenzo[de]isochromene-1,3-dione [L. K.
E. Hardebeck, C. A. Johnson, G. A. Hudson, Y. Ren, M. Watt, C. C. Kirkpatrick, B. M.
Znosko,
M.
Lewis,
J.
Phys.
Org.
Chem.
2013,
26
879–884],
5,8-
dinitrobenzo[de]isochromene-1,3-dione [S. Girouard, M.-H. Houle, A. Grandbois, J. W.
Keillor, S. W. Michnick, J. Am. Chem. Soc., 2005, 127, 559–566] and 5,8diaminobenzo[de]isochromene-1,3-dione [A. Peduto, B. Pagano, C. Petronzi, A. Massa, V.
Esposito, A. Virgilio, F. Paduano, F. Trapasso, F. Fiorito, S. Florio, C. Giancola, A. Galeone,
R. Filosa, Biiorg. Med. Chem. 2011, 19, 6419–6429] were synthesized according to literature
procedure, without modifications and in similar yields.
Synthetic route to IQN1-IQN4
Synthesis of 2-nitro-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one and 5-nitro7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one IQN1.
3-Nitro-1,8-naphthalic acid anhydride (1.62 g, 6.68 mmol) and o-phenylenediamine
(0.72 g, 6.68 mmol) was suspended in acetic acid (50 mL) and the solution was refluxed
overnight. During reflux, a yellow precipitate formed. After cooling, the solvent was removed
under reduced pressure. The residue was suspended in pentane, washed several times with
pentane and dried under vacuum. The product was obtained under the form of a mixture of
isomers (2.04 g, 97% yield). 1H NMR (DMSO d6) δ (ppm): 7.52-7.55 (m, 4H), 7.90-7.93 (m,
2H), 8.07-8.15 (m, 2H), 8.42-8.45 (m, 2H), 8.71 (d, 1H, J = 8.3 Hz), 8.83-8.92 (m, 3H), 9.13
(d, 1H, J = 2.3 Hz), 9.19 (d, 1H, J = 2.2 Hz), 9.39 (d, 1H, J = 2.3 Hz), 9.54 (d, 1H, J = 2.2
Hz); HRMS (ESI MS) m/z: theor: 315.0644 found: 315.0646 (M+. detected); Anal. Calc. for
C18H9N3O3: C, 68.6; H, 2.9; N, 13.3 Found: C, 68.5, H, 2.7; N, 13.4%.
Synthesis of 2-amino-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one and 5amino-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one IQN2.
3-Amino-1,8-naphthalic acid anhydride (1.42 g, 6.68 mmol) and o-phenylenediamine (0.72
g, 6.68 mmol) was suspended in acetic acid (50 mL) and the solution was refluxed overnight.
During reflux, a yellow precipitate formed. After cooling, the solvent was removed under
reduced pressure. The residue was suspended in pentane, washed several times with pentane
and dried under vacuum. The product was obtained under the form of a mixture of isomers
(1.80 g, 94% yield). 1H NMR (DMSO d6) δ (ppm): 7.49-7.52 (m, 4H), 7.81-7.90 (m, 4H),
8.42-8.44 (m, 4H), 8.55-8.62 (m, 6H), 8.81 (s, 2H), 8.97 (s, 2H); HRMS (ESI MS) m/z: theor:
285.0902 found: 285.0899 (M+. detected); Anal. Calc. for C18H11N3O: C, 75.8; H, 3.9; N, 14.7
Found: C, 75.4, H, 3.7; N, 14.6%.
Synthesis of 2,5-dinitro-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one IQN3
3,6-Dinitro-1,8-naphthalic anhydride (1.92 g, 6.68 mmol) and o-phenylenediamine (0.72 g,
6.68 mmol) was suspended in acetic acid (50 mL) and the solution was refluxed overnight.
During reflux, a yellow precipitate formed. After cooling, the solvent was removed under
reduced pressure. The residue was suspended in pentane, washed several times with pentane
and dried under vacuum (2.29 g, 95% yield). 1H NMR (DMSO d6) δ (ppm): 7.52-7.54 (m,
2H), 7.86 (d, 1H, J = 6.7 Hz), 8.31 (d, 1H, J = 6.4 Hz), 9.14 (d, 2H, J = 7.0 Hz), 9.62 (s, 1H),
9.77 (s, 1H); HRMS (ESI MS) m/z: theor: 360.0495 found: 360.0498 (M+. detected); Anal.
Calc. for C18H8N4O5: C, 60.0; H, 2.2; N, 15.5 Found: C, 60.1, H, 2.4; N, 15.6%.
Synthesis of 2,5-diamino-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one IQN4
3,6-Diamino-1,8-naphthalic anhydride (1 g, 4.38 mmol) and o-phenylenediamine (0.47 g,
4.38 mmol) was suspended in acetic acid (20 mL) and the solution was refluxed overnight.
During reflux, a precipitate formed. After cooling, the solvent was removed under reduced
pressure. The residue was suspended in pentane, washed several times with pentane and dried
under vacuum (1.25 g, 95% yield). 1H NMR (DMSO d6) δ (ppm): 5.75 (brs, 2H, NH2), 5.79
(brs, 2H, NH2), 6.92 (s, 1H), 7.04 (s, 1H), 7.46-7.47 (m, 2H), 7.80-7.89 (m, 3H), 8.42 (s, 1H);
HRMS (ESI MS) m/z: theor: 300.1011 found: 300.1009 (M+. detected); Anal. Calc. for
C18H12N4O: C, 72.0; H, 4.0; N, 18.7 Found: C, 71.9, H, 4.1; N, 18.6%.
Figure S1. The emission spectrum of the halogen lamp.
1.00
I (a.u.)
0.75
0.50
0.25
0.00
340
360
380
400 420
 (nm)
440
460
480
Figure S2. The emission spectrum of the LED centered at 405 nm*.
1.00
I (a.u.)
0.75
0.50
0.25
0.00
380
400
420
440
460 480
 (nm)
500
520
540
Figure S3. The emission spectrum of the blue LED centered at 455 nm*.
*For Figures S2 and S3, the nominal wavelengths indicate the wavelengths at which the LEDs appear
brightest to the human eye. This may not correspond to the peak wavelength as measured by a
spectrograph. (from http://www.thorlabs.de/)
1.00
I (a.u.)
0.75
0.50
0.25
0.00
400
450
500
550
 (nm)
600
650
700
Figure S4. The emission spectrum of the cold white LED.
0.010
(b)
(a)
0.008
0.008
0.006
0.006
OD
OD
0.010
0.004
0.004
0.002
0.002
0.000
0.000
400
450
500
550
600
650
0
700
25
 (nm)
50
Time (s)
75
100
Figure S5. (a) Transient absorption spectrum recorded 1 s after the laser excitation (at 355
nm) of IQN1 in nitrogen-saturated acetonitrile and (b) triplet state decay of IQN1 in nitrogensaturated acetonitrile monitored at 460 nm (lifetime: 19.7 s) immediately after the laser
excitation at 355 nm.
70
60
I
(a)
II
50
40
30
20
I
(b)
II
50
Conversion (%)
Conversion (%)
60
40
30
20
10
10
0
0
0
200
400
Time (s)
600
800
0
100
200
Time (s)
300
400
Conversion (%)
I
(c)
60
50
II
40
30
20
10
0
0
100
200
Time (s)
300
400
Figure S6. Photopolymerization profiles of (a) EPOX under air in the presence of
IQN2/Iod/NVK (0.5%/2%/3%, w/w/w) upon the LED@455 nm exposure; (b) TMPTA in
laminate in the presence of IQN2/Iod/NVK (0.5%/2%/3%, w/w/w) upon the LED@405 nm
exposure; (c) TMPTA in laminate in the presence of IQN2/MDEA/R’-Cl (0.5%/2%/3%,
w/w/w) upon the LED@405 nm exposure. curve I - measured from freshly prepared
formulations, curve II - measured after one week of storage at room temperature.