Electronic Supplementary Information (ESI) An Aggregation

1

Electronic Supplementary Information (ESI)

An Aggregation-Induced Emission Luminophore with

Multi-stimuli Single- and Two-Photon Fluorescence

Switching and Large Two-Photon Absorption Cross Section

Bingjia Xu, Mingyuan, Xie, Jiajun He, Bin Xu, Zhenguo Chi,* Wenjing Tian, Long

Jiang, Fuli Zhao,* Siwei Liu, Yi Zhang, Zhizhan Xu, and Jiarui Xu

Experimental section

Materials and Measurements

1-Bromo-1,2,2-triphenylethene, 4-formylphenylboronic acid, tetrabutyl ammonium bromide

(TBAB), and 2-(4-methoxyphenyl)acetonitrile purchased from Alfa Aesar were used as

received. All reagents and chemicals purchased from Alfa Aesar were used as received.

Tetrahydrofuran (THF) was distilled from sodium/benzophenone. Ultra-pure water was used

in the experiments. All other solvents were purchased as analytical grade from Guangzhou

Dongzheng Company and used without further purification.

1H NMR and 13C NMR were measured on a Mercury-Plus 300 spectrometer with chemical

shifts reported as ppm (in CDCl3, TMS as internal standard). Mass spectra were measured

with Thermo spectrometers (DSQ). Elemental analyses (EA) were performed with an

Elementar Vario EL elemental analyzer. FT-IR spectra were obtained on a Nicolet NEXUS

670 spectrometer (KBr pellet).

UV-visible absorption spectra (UV) were determined on a Hitachi U-3900

spectrophotometer. Fluorescence spectra (PL) were measured on a Shimadzu RF-5301PC

spectrometer with a slit width of 3 nm for excitation and 3 nm for emission. Solid state PL

efficiencies were measured with an integrating sphere (Labsphere Inc.), with a 405 nm light as

Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2012

2

the excitation source and the laser was introduced into the sphere through the optical fiber.

Thermal behaviors were determined by differential scanning calorimetry (DSC) at heating and

cooling rate of 10 °C/min under N2 atmosphere using a NETZSCH thermal analyzer (DSC 204

F1). Time-resolved emission decay behaviors were measured on an Endinburgh Instruments

Ltd spectrometer (FLSP920). Wide-angle X-ray diffraction (WAXD) measurements were

performed by using a Bruker X-ray diffractometer (D8 ADVANCE, Germany) with an X-ray

source of Cu Kα (λ= 0.15406 nm) at 40 kV and 40 mA, at a scan rate of 4° (2θ) per 1min.

Ground samples were prepared by grinding using a mortar and pestle. Annealing experiments

were done on a hot-stage with automatic temperature control system. The water/THF mixtures

with different water fractions were prepared by slowly adding distilled water into the THF

solution of samples under ultrasound at room temperature. Scanning Electron Microscopy

(SEM) images were obtained on a HITACHI S4800 microscope operated at 15 kV

The two photon absorption experiments were demonstrated with a regenerative Ti: Sapphire

amplifier system (spectra Physics Hurricane) with a central wavelengths of 740 nm, pulse

duration of 125 fs and repetition rate of 1 kHz. The transmitted light was focused into a

synchroscan streak camera (Hamamatsu Model C1587) connected to a spectroscope.

The TPA cross section (σ) of ENPOMe was measured by the femtosecond open-aperture

Z-scan technique according to a previously described method.1 Figure S4 shows that the TPA

coefficient (β) was obtained by data fitting, and the related equation is given as follows: 2 2

0 03/ 2

0

[ ( ) /(1 / )]( , 1)

( 1)

meff

m

I t L z zT z S

mβ∞

=

+= =

+∑

where z is the distance between the sample and the focus; zo = kw02/2 is the diffraction

length of the beam; k = 2π/λ is the wave vector; λ is the laser wavelength; Leff = (1 - e-αL)/α,

where L is the sample length and α is the linear absorption coefficient; I0 ( t ) is the laser beam

irradiance within the sample; S = 1 - exp(-2ra2/wa

2) is the aperture linear transmittance, with

wa denoting the beam radius at the aperture in the linear regime and β is the nonlinear

absorption coefficient.2 The TPA cross section can be calculated using the equation

σ=hνβ/NAC, in which NA represents the Avogadro constant and C is the molar concentration of

the solute.

Single crystals of the compound were grown from acetonitrile/methanol mixtures. X-ray


3

crystallographic intensity data were collected at 110 K using a Bruker Smart 1000 CCD

diffractometer equipped with graphite monochromated Enhance (Mo) X-ray source (λ =

0.71073 Å). The structures were solved by the direct methods following difference Fourier

syntheses, and refined by the full-matrix least-squares method against F02 using SHELXTL

software.3 Crystallographic data for the structure(s) reported in this paper have been deposited

with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-

898288.

Synthesis

Br

B OHHO

HOO

Pd(PPh3)4 , K2CO3 (2M)TBAB, Toluene, 90oC

P4A

OC

CH3

N

Ethanol, N(n-Bu)4OH (0.8M)reflux

CO

CH3

N

ENPOMe

Scheme S1 The synthesis routes of the desired compounds.

Synthesis of P4A

The compound of P4A was synthesized as the literature method.4

Synthesis of ENPOMe

A solution of P4A (1.00 g, 2.77 mmol) and 2-(4-methoxyphenyl)acetonitrile (0.45 g, 3.05 mmol)

in ethanol (30 mL) was stirred at room temperature. Then terabutyl ammonium hydroxide solution

(0.8 M, 5 drops) was added and the mixture was heated to reflux for 2 hours precipitating a light

green solid. The reaction mixture was cooled to room temperature and filtered, washed with

ethanol for several times obtaining a light green powder. Yield: 89% (1.21 g). 1H NMR (300 MHz,

CDCl3) δ(ppm): 7.63—7.58 （d, 2 H); 7.57—7.51 (d, 2 H); 7.29—7.26 (s, 1 H); 7.14—6.99 (m,

17 H); 6.95—6.89 (d, 2 H); 3.85—3.81 (s, 3 H). 13C NMR (75MHz, CDCl3) δ(ppm): 159.96,

145.72, 143.09, 143.03, 142.92, 141.85, 139.77, 139.57, 131.59, 131.02, 128.23, 127.61, 127.56,

127.40, 126.95, 126.58, 126.41, 118.06, 114.15, 109.94, 109.50, 55.31. FT-IR (KBr) υ (cm-1):

3017, 2217, 1600, 1500, 1250, 1033, 829, 770, 700. EI-MS, m/z: [M]+ 489 , calcd for C36H27NO

489. Anal. calcd for C36H27NO: C 88.31, H 5.56, N 2.86, O 3.27; found: C 88.25, H 5.61, N 2.83,


4

O 3.30.

References

1 B. Z. Tang, Y. H. Geng, J. W. Y. Lam, B. S. Li, X. B. Jing, X. H. Wang, F. S. Wang, A. B.

Pakhomov and X. X. Zhang, Chem. Mater., 1999, 11, 1581.

2 Q. Q. Li, S. S. Yu, Z. Li and J. G. Qin, J. Phys. Org. Chem., 2009, 22, 241.

3 Sheldrick, G. M. SHELX-97: Program for crystal structure solution and refinement, University

of Götingen, Götingen, Germany, 1997.

4 X. Q. Zhang, Z. G. Chi, H. Y. Li, B. J. Xu, X. F. Li, W. Zhou, S. W. Liu, Y. Zhang, J. R. Xu,

Chem.- Asian J. 2011, 6, 808.


5

Figures and tables

350 450 550 6500

100

200

300

400 Water fraction (%)

Inte

nsity

(a.u

.)

Wavelength (nm)

0 10 20 30 40 50 60 70 80 90 98

0 20 40 60 80 1000

100

200

300

400

Inte

nsity

(a.u

.)

Water fraction (v%)

Figure S1. PL spectra of the dilute solutions of ENPOMe in water/THF mixtures with different

water fractions (concentration: 10 μM, excitation wavelength: 370 nm). The inset depicts changes

in PL peak intensity (up) and emission images of the compound in pure THF and 98% water

fraction mixtures under 365 nm UV illumination (10 μM) (down).

350 450 550 650 750

0.0

0.2

0.4

0.6

0.8

1.0

Water fraction (%)

Inte

nsity

(a.u

.)

Wavelength (nm)

0 70 80 90 98

Figure S2. UV absorption spectra of ENPOMe in water/THF mixtures with different volume

fraction of water. (concentration: 10 μM).


6

400 500 600 700 800

0

1000

2000

3000

4000

-0.2 -0.1 0.0 0.1 0.2 0.3 0.4-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

Log (P)

Log

(I)

ENOPMe Powder Linear Fit of the Sample

Y = 2.0292X - 0.1948

Inte

nsity

(a.u

.)

Wavelength (nm)

P

Figure S3. TPF emission spectra for ENPOMe with different input powers. The inset depicts the

plot of emission intensity versus input laser power for ENPOMe on a log/log scale. The fit of the

experimental data is shown in red, and the corresponding equation is reported in the inset. (The

excitation was 740 nm laser pulse).

Figure S4. Calculated spatial electron distributions of highest occupied molecular orbital (HOMO)

and lowest unoccupied molecular orbital (LUMO) of ENPOMe.


7

450 550 650 7500

100

200

300

400

500

600

700

Water fraction (%)

Inte

nsity

(a.u

.)

Wavelength (nm)

0 70 80 90 98 0 20 40 60 80 100

0

100

200

300

400

500

600

700

Inte

nsity

(a.u

.)

Water fraction (v%)

Figure S5. Two Photon Fluorescence (TPF) emission spectra of the dilute solutions of ENPOMe

in water/THF mixtures with different water fractions (concentration: 10 μM; excitation

wavelength: 740 nm laser pulse). The inset depicts changes in TPF peak intensity (up) and TPF

emission images of the compound in pure THF and 98% water fraction mixtures under 740 nm

femtosecond laser illumination (10 μM) (down).

50 100 150 200

Temperature (oC)

Endo

B3-a

B3-v

G2

B2-a

B2-v

G1

B1

82 oC

Figure S6. DSC curves of ENPOMe : (B1) as-synthesized sample; (G1) ground sample; (B2v)

fumed sample (ground sample in dichloromethane vapor for five min); (B2a) annealed sample (The

ground sample was homoiothermal at 140 oC for ten minutes, and then, cooled down to room

temperature.); (G2) re-ground sample; (B3v) re-fumed sample; (B3a) re-annealed sample. (First

hyperthermic treatments).


8

0 10 20 30

Time (ns)

PL in

sten

sity

(a.u

.)

As-synthesized sample Ground sample

Figure S7. Time-resolved emission decay curves of the as-synthesized sample and the ground

sample of ENPOMe.

0 10 20 30 40 50

Inte

nsity

(a.u

.)

(deg)

G2

G1

B3v

B2v

B3a

B2a

B1

Figure S8. Powder WXRD patterns of ENPOMe at different morphology: (B1) as-synthesized

sample; (G1) ground sample; (B2v) fumed sample (ground sample in dichloromethane vapor for

ten minutes); (B2a) annealed sample (The ground sample was homoiothermal at 140 oC for five

minutes, and then, cooled down to room temperature.); (G2) re-ground sample; (B3v) re-fumed

sample; (B3a) re-annealed sample.


9

350 400 450 500 550 600 650 700 750 800

0.0

0.2

0.4

0.6

0.8

1.0

Wavelength (nm)

I/I0

As-synthesis sample-370 nm As-synthesis sample-740 nm Ground sample-370 nm Ground sample-740 nm

Figure S9. SPF emission spectra and TPF emission spectra of the as-synthesized sample and the

ground sample.

350 400 450 500 550 600 650 700

0.0

0.2

0.4

0.6

0.8

1.0

B1 G1 B2a G2 B3a460

470

480

490

500

510

520

Wav

elen

gth

(nm

)

Morphology

B1 G1 B2v G2 B3v460

470

480

490

500

510

520

Wav

elen

gth

(nm

)

Morphology

Wavelength (nm)

I/I0

B1 G1 B2v B2a G2 B3v B3a

Figure S10．SPF spectra of ENPOMe: (B1) as-synthesized sample; (G1) ground sample; (B2v)

fumed sample (ground sample in dichloromethane vapor for five minutes); (B2a) annealed sample

(The ground sample was homoiothermal at 140 oC for ten minutes, and then, cooled down to room

temperature.); (G2) re-ground sample; (B3v) re-fumed sample; (B3a) re-annealed sample. The insets

depict the reversibility of the SPF wavelengths of ENPOMe: by grinding-fuming treatments (up);

and by grinding-annealing treatments (down).


10

Figure S11. Single crystal structure: a) molecular packing; b) molecular packing in a unit cell; c)

molecular interactions in a single crystal; d) molecular packing in space-fill representations.


11

Table S1 Crystal data and structure refinement for ENPOMe

Identification

Formula C36 H27NO

Formula weight. 489.59 g/mol

T (K) 110(2)

Crystal system monoclinic

Space group P 1 21/c 1 (14)

a (Å) 26.602(4)

b (Å) 5.8933(9)

c (Å) 17.336(3)

α (°) 90.00

β (°) 101.602(3)

γ (°) 90.00

V (Å3) 2662.3(7)

Z 4

dcalc. (g cm-3) 1.2214

Adsorption coefficient (mm-1) 0.068

F(000) 1032

Crystal size (mm3) 0.44 x 0.42 x 0.41

Theta range for data collection 2.34~27.05

Index range -28≤h≤33, -7≤k≤7, -13≤l≤22

Reflections collected/uniq. (Rint) 12855 / 5693 [R(int) = 0.0210]

Completeness to theta = 27.05 97.2 %

Absorption correction Semi-empirical from equivalents

Max. and min. transmission 0.9709 and 0.9688

Refinement method Full-matrix least-squares on F2

Data / restraints / parameters 5693 / 0 / 344


12

R1 (wR2)a, [I > 2sigma(I)] R1 = 0.0384, wR2 = 0.0899

R1 (wR2)a, (all data) R1 = 0.0569, wR2 = 0.0999

Goodness-of-fit on F2 1.027

Largest diff. peak and hole (e·Å-3) 0.250 and -0.186

aR1 = Σ⎥⎥ Fo⎥–⎥ Fc⎥⎥/Σ⎥ Fo⎥. b wR2 = [Σ[w(Fo2–Fc

2)2]/Σw(Fo2)2]1/2.

A

B

C

D E

F

Figure S12. The molecular conformation of ENPOMe

Table S2 The dihedral angles of the selected planes of the molecule in single crystal and free

molecule

Plane A-D A-B C-D D-F D-E

Free molecule [a] 75.2 57.8 58.0 5.7 31.4

Single crystal [b] 80.5 58.7 58.6 14.4 26.4

[a] Geometry from calculation using Gaussian 03; [b] Geometry from single crystal.


13

-15 -10 -5 0 5 10 15

0.94

0.95

0.96

0.97

0.98

0.99

1.00

Nor

mal

ized

Tra

nsm

itanc

e

Z(mm)

Figure S13. Normalized Z-scan transmittance of ENPOMe. (Using femtosecond laser pulse at

λ=740 nm, concentration of ENPOMe: 10 mM in THF). The solid line is the theoretical result.


14

Structural information of ENPOMe

1H NMR

13C NMR


15

MS

Instrument:DSQ(Thermo)Ionization Method: EID:\DSQ\DATA-LR\12\010903 1/9/2012 10:23:43 AM ENPOMe

010903 #206 RT: 2.54 AV: 1 NL: 3.12E7T: + c Full ms [45.00-600.00]

50 100 150 200 250 300 350 400 450 500 550m/z

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

Rel

ativ

e A

bund

ance

489

231

170265 412201 291 33971 47438057 31515291 445

FI-IR


16

4000 3000 2000 100040

60

80

100

Tran

smitt

ance

(%)

Wavenumber (cm-1)

1600

1500

829

770

700

3017 2217

12501033


Documents

Electronic Supplementary Information (ESI) An Aggregation