Supporting Information
A new luminescent metal-organic framework for selective sensing of nitroaromatic explosives
Tingting Wang1, Yanyuan Jia2, Qiang Chen1, Rui Feng2,Shouyi Tian2,Tongliang Hu1,3* and Xianhe Bu1,2,3
1School of Materials Science and Engineering, National Institute for Advanced Materials, TKL of Metal and Molecule-Based Material Chemistry, Nankai University, Tianjin 300350, China.
2College of Chemistry, Nankai University, Tianjin 300071, China
3Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China
* Corresponding author. E-mail:
1. Synthesis of H4L and general characterizations
1H-pyrazole-3,5-dicarboxylic acid(30 mmol, 4.68g) was dissolved in 200 mL of dichloromethane containing 75 mL of thionyl chloride. The clear faint yellow solution was refluxed undernitrogenfor 24 h. The solvent was evaporated to generate 1H-pyrazole-3,5-dicarbonyl dichloride as a light yellow powder.5-Aminoisophthalic acid (65 mmol, 11.70g) and 4-(dimethylamino)pyridine (6.75 mmol, 0.80g) were dissolved in 75 mL of anhydrous N,N-dimethylacetamide under nitrogen. 1H-pyrazole-3,5-dicarbonyl dichloride was dissolved in 75 mL of anhydrous N,N-dimethylacetamide and added in drops. The mixture was stirred under nitrogen for 96 h to give a light yellow solution. The reaction mixture was then transferred to a 1000mL flask. 150 mL of 5% HCl was added to precipitate the product and dissolve excess 5-aminoisophthalic acid and 4-(dimethylamino)pyridine. The solid was washed by 250 mL distilled water about 5 times. The damp product was kept in oven overnight to give a pale yellow powder (83% yield).Data for H4L:Selected IR (KBr, cm-1): 3313 (m), 2603 (m), 1699 (s), 1558 (s), 1434 (m), 1191 (s), 1014 (w), 761 (m), 674 (m).1H NMR (DMSO-d6, δppm): 14.50 (4H, COOH), 10.70 (2H, CONH), 8.66 (4H, ArH), 8.18 (2H, ArH), 7.71 (1H, PyrH).1H NMR spectrum and IR spectra of H4L were shown in Fig. S1 and Fig.S2, respectively.
Fig. S1. 1H NMR spectrum of H4L.
Fig. S2.IR spectrum of the ligand H4L.
Fig. S3.IR spectrum of the complex 1.
Fig. S4. (a) Coordination environment of Zn atoms in 1. Symmetry codes: A=-x, -y, 0.5+z;B=x, -1+y,z;C=-0.5+x, -0.5-y,z;D=0.5-x,-1.5+y, 0.5+z; E=-x, -1-y, 0.5+z; F=0.5-x,-0.5+y, 0.5+z; G=-0.5+x, 0.5-y, z. (b) Connection diagram of Zn1-Zn4 cluster and Zn2-Zn3 cluster. (c) The 2D layers formed by ligands L1 and Zn2+ atoms. (d) The 3D structure of 1 along b axis. Color scheme: Zn (blue-green); O (red); C (green); N(blue).
Fig. S5.(a) The 3D structure of 1 along a axis. (b) The space-filling representation of 1 along the b axis. Color scheme: Zn (blue-green); O (red); C (black); N(blue).
Fig. S6.The PXRD patterns of complex 1.
2 Thermogravimetric Analysis (TGA)
TGA of complex 1 shows an obvious weight loss of ~12% in the temperature range of 44–168 °C, corresponding to the loss of guest water molecules and DMA molecules. Then the framework would decompose at temperatures above 310 °C.
Fig. S7.Thermogravimetric analyses (TGA) curve for complex1.
Fig. S8.Solid-state photoluminescent spectra of free H4L ligand (black, λex = 325 nm) and complex 1 (red, λex= 335 nm),excitation spectra of complex 1at room temperature at room temperature.
Fig. S9.Emission spectra of free H4L ligand (black, λex = 345 nm) and complex 1 (red, λex = 320 nm) dispersed in DMAat room temperature.
Fig. S10.1H NMR spectrum of the filtrate of complex1 dispersed in d9-DMA after ultrasonication.
Fig. S11.Emission spectra of 1 in different solvents when excited at 320 nm.
Fig. S12.Emission intensities of 1 in different solvents when excited at 320 nm.
3 Fluorescence quenching titrations in dispersed medium
The fluorescence of complex1 was measured by dispersing 3 mg of grounded sample in 3 mL DMA treated by ultrasonication for 30 min and then aged for 36 hours to form a stable suspension solution. Subsequently the suspension solution was placed in a quartz cell of 1 cm width. All titrations were carried out by gradually adding nitroaromatic explosives in an incremental fashion. Their corresponding fluorescence emission spectra were recorded at 298 K. Eachtitration was repeated several times to get concordant value. For all measurement, disperse solutions of 1 wereexcited at λex = 320 nm and their corresponding emission wavelength was monitored from 330nm to 615 nm. Therewas no change in shape of the emission spectra by gradual addition of nitroaromatic explosives, to disperse solution of 1 in DMA, only quenching of the initial fluorescence emission intensity was observed.
Fig. S13.Fluorescence titration of complex 1 dispersed in DMA with the addition of different concentrations of nitrobenzene. Excitation wavelength was 320 nm and fluorescence emission was monitored from 330 nm to 615 nm.
Fig. S14.Fluorescence titration of complex 1 dispersed in DMA with the addition of different concentrations of 1,3-dinitrobenzene. Excitation wavelength was 320 nm and fluorescence emission was monitored from 330 nm to 615 nm.
Fig. S15.Fluorescence titration of complex 1 dispersed in DMA with the addition of different concentrations of 2,4-dinitrotoluene. Excitation wavelength was 320 nm and fluorescence emission was monitored from 330 nm to 615 nm.
Fig. S16.Emission spectra of 1 (3mg) dispersed in 3mL DMA with the addition of 2000ppm different nitroaromatic explosives.
Fig. S17.The PXRD patterns of complex 1 immersing in different organic solvents for 72 h.
Fig. S18. Plot of the quenching efficiency of 1 dispersed in DMA at different concentrations of 1,3-dinitrobenzene. Inset: linear relation between the quenching efficiency and the concentrations of 1,3-dinitrobenzene in the range of 5-200 ppm.
Fig. S19.Plot of the quenching efficiency of 1 dispersed in DMA at different concentrations of 2,4-dinitrotoluene. Inset: linear relation between the quenching efficiency and the concentrations of 2,4-dinitrotoluene in the range of 5-200 ppm.
Table S1. Crystal data and structure refinement for complex 1.
Formula / C42 H18 N8 O22 Zn4Fw / 1248.12
T/K / 293(2)
λ/Å / 0.71073
Crystal system / Orthorhombic
Space group / Pna21
a/Å / 20.347(4)
b/Å / 11.739(2)
c/Å / 33.130(7)
α/° / 90
β/° / 90
γ/° / 90
V/Å3 / 7913(3)
Z / 4
Dc/Mg·cm-3 / 1.048
μ/mm-1 / 1.254
F(000) / 2488
unique reflns / 12896
Rint / 0.0776
R1a[I＞2σ(I)] / 0.0535
wR2b[I＞2σ(I)] / 0.1190
GOF on F2 / 0.943
aR1= FoFc / Fo; bwR2= [[w(Fo2Fc2)2] / w(Fo2)2]1/2.
Table S2. Bond lengths [Å]and angles [º] for complex 1.
Zn(1)-O(14)#1 / 1.957(5) / Zn(3)-O(15)#5 / 1.942(5)Zn(1)-O(1) / 1.958(4) / Zn(3)-O(12)#6 / 2.004(4)
Zn(1)-O(8)#2 / 1.962(4) / Zn(3)-N(2)#4 / 2.022(5)
Zn(1)-N6)#3 / 2.021(5) / Zn(3)-O(4) / 2.033(4)
Zn(2)-O(21) / 2.014(4) / Zn(3)-O(9)#4 / 2.311(5)
Zn(2)-O(3) / 2.030(4) / Zn(4)-O(5) / 1.987(5)
Zn(2)-N(1)#4 / 2.045(5) / Zn(4)-O(22) / 2.026(6)
Zn(2)-O(17)#3 / 2.111(5) / Zn(4)-N(5) / 2.054(5)
Zn(2)-O(10)#4 / 2.247(4) / Zn(4)-O(13)#7 / 2.087(5)
Zn(2)-O(18)#3 / 2.409(7) / Zn(4)-O(19) / 2.165(5)
O(14)#1-Zn(1)-O(1) / 103.6(2) / O(17)#3-Zn(2)-O(18)#3 / 58.1(2)
O(14)#1-Zn(1)-O(8)#2 / 105.5(2) / O(10)#4-Zn(2)-O(18)#3 / 95.20(2)
O(1)-Zn(1)-O(8)#2 / 106.22(2) / O(15)#5-Zn(3)-O(4) / 97.1(2)
O(14)#1-Zn(1)-N(6)#3 / 112.9(2) / O(12)#6-Zn(3)-O(4) / 99.06(2)
O(1)-Zn(1)-N(6)#3 / 119.11(2) / N(2)#4-Zn(3)-O(4) / 97.32(2)
O(8)#2-Zn(1)-N(6)#3 / 108.5(2) / O(15)#5-Zn(3)-O(9)#4 / 98.2(2)
O(21)-Zn(2)-O(3) / 92.50(2) / O(12)#6-Zn(3)-O(9)#4 / 80.24(2)
O(21)-Zn(2)-N(1)#4 / 105.7(2) / N(2)#4-Zn(3)-O(9)#4 / 73.54(2)
O(3)-Zn(2)-N(1)#4 / 104.72(2) / O(4)-Zn(3)-O(9)#4 / 163.88(2)
O(21)-Zn(2)-O(17)#3 / 152.7(2) / O(5)-Zn(4)-O(22) / 109.1(3)
O(3)-Zn(2)-O(17)#3 / 91.1(2) / O(5)-Zn(4)-N(5) / 125.4(2)
N(1)#4-Zn(2)-O(17)#3 / 99.5(2) / O(22)-Zn(4)-N(5) / 122.9(3)
O(21)-Zn(2)-O(10)#4 / 84.45(2) / O(5)-Zn(4)-O(13)#7 / 96.7(2)
O(3)-Zn(2)-O(10)#4 / 176.94(2) / O(22)-Zn(4)-O(13)#7 / 91.4(3)
N(1)#4-Zn(2)-O(10)#4 / 76.22(2) / N(5)-Zn(4)-O(13)#7 / 97.7(2)
O(17)#3-Zn(2)-O(10)#4 / 91.58(2) / O(5)-Zn(4)-O(19) / 87.6(2)
O(21)-Zn(2)-O(18)#3 / 95.3(2) / O(22)-Zn(4)-O(19) / 90.0(3)
O(3)-Zn(2)-O(18)#3 / 85.04(2) / N(5)-Zn(4)-O(19) / 77.4(2)
N(1)#4-Zn(2)-O(18)#3 / 156.2(2) / O(13)#7-Zn(4)-O(19) / 174.82(2)
Symmetry codes: #1 -x+1/2,y-1/2,z+1/2; #2 -x,-y-1,z+1/2; #3 -x,-y,z+1/2; #4 x,y-1,z; #5 -x+1/2,y-3/2,z+1/2; #6 x-1/2,-y-1/2,z; #7 x-1/2,-y+1/2,z;
References
(a)G. M. Sheldrick, SHELXL97, Program for Crystal Structure Refinement;University of Göttingen: Göttingen, Germany, 1997.
(b) G. M. Sheldrick, SHELXS97, Program for Crystal Structure Solution; University of Göttingen: Göttingen, Germany, 1997.
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