Supporting Information
Synthesis, luminescent properties of aza-boron-diquinomethene difluoride complexes
and their application for fluorescent security inks
Long Gua, Rui Liua,*, Hong Shib, Qiang Wanga, Guangliang Songa, Xiaolin Zhua,
Shidong Yuanc, Hongjun Zhua,*
a
Department of Applied Chemistry, College of Chemistry and Molecular Engineering,
Nanjing Tech University, Nanjing 210009, China
b
Jiangsu Vocational College of Information Technology, Wuxi 214153, China
c
Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai
200083, China
*Corresponding author. Phone: +86-25-58139539. Fax: +86-25-58139539. E-mail:
rui.liu@njtech.edu.cn (R. Liu)
*Corresponding author. Phone: +86-25-83172358. Fax: +86-25-83587428. E-mail:
zhuhj@njtech.edu.cn (H. Zhu)
1. Determination of quantum yield at different pH conditions.
The photoluminescence quantum yields of the B1 and B2 were measured in a mixture
of phosphate buffer saline (PBS, pH = 1~12, 20 mM) and THF (1:9, v/v), using
9,10-diphenylanthracene as a reference with a known Ф value of 0.97 in cyclohexane
at room temperature. The sample and the reference were excited at the same
wavelength (λex = 366 nm), maintaining nearly equal absorbance (0.05). The quantum
yield was calculated according to the following Eq. (1):
Φ
A F
n
 Φ  s  u  ( u )2
u
s A
F
n
u s
s
(1)
where Фu and Фs are the fluorescence quantum yields of the sample and the reference,
respectively; Fu and Fs are the emission areas of the sample and the reference,
respectively; Au and As are the corresponding absorbance of the sample and the
reference solution at the wavelength of excitation; nu and ns are the refractive indices
of the sample and the reference, respectively. The fluorescence quantum yield of B1
and B2 in different pH were investigated and the results are listed in Table S1.
Table S1 The fluorescence quantum yield of B1 and B2 in different pH conditions.
pH
1
2
3
4
5
6
7
8
9
10
11
12
B1
ΦPL
0.72
0.75
0.82
0.88
0.89
0.87
0.98
0.80
0.74
0.72
0.74
0.69
B2
ΦPL
0.46
0.55
0.56
0.53
0.84
0.75
0.81
0.81
0.61
0.62
0.61
0.60
2. Thermal properties
Fig S1. DSC thermograms of B1 and B2 under a nitrogen atmosphere at a heating rate of 10 °C
min−1.
Table S2. Thermal properties of complexes B1 and B2
complex
Tm (oC)
B1
257
B2
383
3. The solvatochromic effect
Hexane
Toluene
THF
DCM
ACN
MeOH
Normalized Absorption (a.u.)
1.0
0.8
0.6
0.4
0.2
Normalized Emission Intensity (a.u.)
Fig S2.Normalized absorption and emission spectra of B1 in different solvents (1 × 10-5 M)
1.0
Hexane
Toluene
THF
DCM
ACN
MeOH
0.8
0.6
0.4
0.2
0.0
0.0
400
450
Wavelength (nm)
500
500
600
Wavelength (nm)
Fig S3.Normalized absorption and emission spectra of B2 in different solvents (1 × 10-5 M)