Supporting Information
Supporting Information A Photo-Driven Polyoxometalate Complex Shuttle and Its Homogeneous Catalysis and Heterogeneous Separation Yang Yang, Bin Zhang, Yizhan Wang, Liang Yue, Wen Li,* and Lixin Wu* State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China Corresponding Author: [email protected], [email protected]
Materials.
Na12[WZn3(H2O)2(ZnW9O34)2]
(Zn5W19O68),
(NH4)72{(Mo)Mo5O21(H2O)6}12{Mo2O4(SO4)}30 (Mo132) and K12.5Na1.5[NaP5W30O110] (P5W30) were freshly prepared according to the literature.1-3 Phenothiazine was purchased from Sinopharm Chemical Reagent Co. Ltd. Cumyl hydroperoxide was the product of Aladdin Chemistry Co. Ltd. All the compounds were used without further purification, and all the used solvents were analytical grade. Doubly distilled water was used in the experiments. Silica gel (100-200 mesh) was applied for column chromatography. The quaternary ammonium bearing azobenzene (Azo) groups at the end of tails, Azo-ended surfactant (AzoC6)2N, and 1-(4-(6-bromohexy)phenyl)-2-phenyldiazene (1) was synthesized according to the literature.4 The surfactant (AzoC6)(C4)N was synthesized and the detailed synthetic procedures are described in Scheme S1. The chemical structure of surfactant (AzoC6)(C4)N was confirmed by 1H NMR.
Scheme S1. Synthetic route of surfactant (AzoC6)(C4)N. S1
(AzoC6)(C4)N: A mixture of (1) (2.0 g, 5.5 mmol), 1-butanamine (2.8 g, 38.3 mmol) in ethanol (50 mL) was refluxed for 24 h. After the solvent was evaporated, the reaction mixture was purified by recrystallization in anhydrous diethyl ether, giving a yellow solid. (yield: 2.1 g, 87.5%). 1H NMR (CDCl3, TMS): δ = 0.951 (t, J = 7.5 Hz, 3H), 1.485 (m, 6H), 1.904 (m, 6H), 2.955 (m, 4H), 4.019 (t, J = 6.5 Hz, 2H), 6.972 (d, J = 8.5 Hz, 2H), 7.429 (t, J = 8 Hz, 2H), 7.494 (t, J = 8 Hz, 2H), 7.874 (d, J = 8 Hz, 2H), 7.891 (d, J = 8.5 Hz, 2H).
Characterization of POM complexes. The chemical composition of the Azo-SEP with Azo groups on the periphery was confirmed by
1
H NMR, FT-IR, elemental analysis, and
1
thermogravimetric (TG) measurements. H NMR (CDCl3, TMS): δ = 1.312 (m, 16H), 3.296 (s, 6H), 3.536 (s, 4H), 3.936 (s, 4H), 6.990 (d, J = 7.5 Hz, 4H), 7.373 (t, J = 7.0 Hz, 2H), 7.435 (t, J = 7.5 Hz, 4H), 7.831 (m, 8H). 1H NMR (DMF-d7/D2O (1:1 in volume ratio), TMS): δ = 1.590 (m, 16H), 3.324 (s, 6H), 3.537 (s, 4H), 4.104 (s, 4H), 7.018 (m, 12H), 7.388 (s, 2H), 7.524 (s, 4H). FT-IR (KBr): ν = 3431, 2941, 2866, 1600, 1581, 1501, 1472, 1389, 1300, 1254, 1142, 920, 874, 839, 768, 723 cm–1. Anal. Calcd for Azo-SEP (C342H436N45O88W19Zn5Na3, 10474.25): C 39.22, H 4.20, N 6.02. Found: C 39.65, H 4.25, N 6.04, corresponding to the chemical formula: [(AzoC6)2N]9Na3[WZn3(H2O)2(ZnW9O34)2] (10474.25). The TG measurement suggests a 53.5% (in w/w) of mass loss at the temperature between 40 and 700 °C. The MALDI-TOF result around 10475 proves the proposed chemical formula. The chemical compositions of (Mo132) and (P5W30) complexes were charaterized by elemental analysis. Anal. Calcd for (Mo132) complex (C1254H2080N204O728S30Mo132, 45288.93): C 33.26, H 4.63, N 6.31. Found: C 33.35, H 4.55, N 6.12, corresponding
to
the
chemical
formula:
[(AzoC6)2N]33(NH4)39(H2O)48Mo132O372(H2O)72(SO4)30(H2O)50 (45288.93). Anal. Calcd for (P5W30) complexes (C286H416N39O123W30P5Na2 or C286H416N39O123W30P5NaK, 12084.60 or 12100.71): C 28.43 or 28.39, H 3.47 or 3.47, N 4.52 or 4.51. Found: C 28.71, H 3.45, N 4.48, corresponding to the chemical formula: [(AzoC6)(C4)N]13Na[NaP5W30O110] (12084.60) or [(AzoC6)(C4)N]13K [NaP5W30O110] (12100.71).
Catalytic Procedure: Azo-SEP (1.0×10–4 mmol), 80-85% CHP (0.1 mmol) and PH (1.0×10–2 mmol) were dissolved in toluene (2 mL) in a 10 mL flask and stirred (1000 r min–1) at 30 °C for a certain period time. The reaction progress was monitored by TLC and UV-Vis. After the reaction, H2O/DMF mixed solvents (2 mL) was added, and the solution was irradiated by UV light to trigger the phase transfer of Azo-SEP to H2O/DMF phase. After phase separation, the Azo-SEP catalyst was recovered upon visible light irradiation, which induced the phase transfer of the catalyst back to toluene phase. S2
Photo-irradiation. For UV irradiation of the Azo-SEP solution (3.0 mL) sealed in a quartz cell, WHF 203 UV lamp (365 nm) was used. For visible light irradiation, 200-W incandescent light bulb (>440 nm) was applied. The irradiation time is limited in 10 min and distance between the light source and sample is kept at 10 cm.
Measurements. 1H NMR spectra were recorded on a Bruker Avance 500 instrument using TMS as internal reference. Fourier transform infrared (FT-IR) spectral measurement on pressed KBr pellets was performed on a Bruker IFS66v FT-IR spectrometer equipped with a DGTS detector (32 scans) with a resolution of 4 cm–1. Organic elemental analysis (C, H, N) was carried out on a Flash EA1112 analyzer from ThermoQuest Italia S.P.A., while inorganic elemental analysis (W) was performed on a POEMS inductively coupled plasma atomic emission spectrometer (ICP-AES) (TJA, USA). Thermogravimetric (TG) thermograms were conducted on a Perkin-Elmer Diamond TG/DTA instrument with a heating rate of 10 °C min–1 under flowing air. Matrix-assisted laser desorption/ionization time-of-flight mass spectrum (MALDI-TOF) mass spectrum was recorded on an autoflex TOF/TOF (Bruker, Germany) mass spectrometer, equipped with a nitrogen laser (337 nm, 3 ns pulse), and operated in the positive ion reflector mode with a detector potential of -4.75 kV. The matrix DCTB was employed. The mass range for data acquisition is from m/z 2000 to 14000 Da. X-ray photoelectron spectroscopy (XPS) was performed on an ESCALAB 250 spectrometer with a monochromic X-ray source (AlKa line, 1486.6 eV) and the charging shift was corrected by the binding energy of C(1s) at 284.6 eV. UV-Vis spectra were performed on a Shimadzu UV-3600 Spectrophotometer. Transmission electron microscopy (TEM) images were obtained with a Hitachi H8100 electron microscope with accelerating voltage of 200 KV without staining. Scanning electron microscopic (SEM) measurement was performed on a JEOL JSM–6700F field emission scanning electron microscope. Dynamic light scattering (DLS) measurements were done using a Zetasizer NanoZS (Malvern Instruments). The HPLC analysis was performed on SHIMADZU LC-20A with an Aglient ZORBAX SB-C18 column (d = 5 μm, l = 250 mm) at 40 °C. The eluent was methanol/H2O (70:30) at a flow rate of 1 mL min–1.
S3
Supplement Data.
Figure S1. 1H NMR spectrum of (AzoC6)(C4)N in CDCl3. The letters without prime correspond to the tans- form, and the letters with prime ascribe to the cis- form.
Figure S2. TG curve of Azo-SEP, which was carried out in air with a heating rate of 10 °C –1
min .
S4
Figure S3. 1H NMR spectra of (AzoC6)2N and Azo-SEP in CDCl3.
Figure S4. 1H NMR spectra of cis-(AzoC6)2N and cis-Azo-SEP in D2O/DMF-d7 (1:1 in volume ratio).
S5
Figure S5. FT-IR spectra of pure Zn5W19O68, (AzoC6)2N, and Azo-SEP in KBr pellets. Table S1. The Assignments for Characteristic Vibrations of (AzoC6)2N, POM, and Azo-SEP in FT-IR Spectra. (AzoC6)2N (cm–1)
Azo-SEP (cm–1)
Zn5W19O68 (cm–1)
3422
3431
3398
O–H asym. str.
2947
2941
-
CH3 asym. str.
2870
2866
-
CH2 sym. str.
-
-
1622
1605 1582 1502
1600 1581 1501
-
C=C framework str.
1474
1472
-
CH2N scissoring
1394
1389
-
CH3 scissoring
1302
1300
-
CH2 wagging
1256
1254
-
=C–O–C asym. str.
1146
1142
-
C–N str.
1057
-
-
=C–O–C asym. str.
-
920
926
W–Od asym. str.
-
874
881
W–Ob–W asym. str.
835
839
-
-
768
770
723
723
-
Assignments[a]
O–H scissoring
C–H str. W–Oc–W asym. str. CH2 rocking
[a] Asym. str., antisymmetrical stretching; sym. str., symmetrical stretching. S6
Figure S6. MALDI-TOF mass spectrum of Azo-SEP. The
central
peak
around
10475
corresponds
to
the
chemical
formula
of
[(AzoC6)2N]9Na3[Zn5W19O68], while the peak at 9892 is in agreement with the formula of [(AzoC6)2N]8Na4[Zn5W19O68], and the peak at 11082 is coincident to the formula of [(AzoC6)2N]10Na2[Zn5W19O68]·Na+. The datum reveals that the obtained complex has an average chemical formula of [(AzoC6)2N]9Na3[Zn5W19O68] (10474.25).
Figure S7. W(4f) XPS spectra of Azo-SEP before (black) and after 5 cycles of UV and visible light irradiations (red).
S7
Figure S8. DLS diagrams of Azo-SEP in a) toluene solution, and b) H2O/DMF mixed solution. Insets: corresponding photographs of Azo-SEP solutions upon UV and visible light irradiations.
Figure S9. a) TEM image of Azo-SEP in toluene solution before UV irradiation, b) SEM image after UV irradiation, and c) TEM image after a subsequent UV and visible light irradiation cycle; and d) SEM image of Azo-SEP in H2O/DMF mixed solution before UV irradiation, e) TEM image after UV irradiation, and f) SEM image after a subsequent UV and visible light irradiation cycle.
S8
Figure S10. UV-Vis spectra of Azo-SEP in a) toluene and b) H2O/DMF mixed solvents encountering alternate UV and visible light irradiations. (Black line: initial state, red line: encountering one cycle, blue dash: encountering ten cycles of UV and visible light irradiations)
Figure S11. UV-Vis spectra of Azo-SEP in toluene upon a) UV and b) visible light irradiation, and in H2O/DMF upon c) UV and d) visible light irradiation.
S9
Figure S12. Plots of absorbance of Azo-SEP in a) toluene at 349 nm, and in b) H2O/DMF at 348 nm upon UV and visible light irradiation, summarized from UV-Vis spectra versus the time.
Figure S13. 1H NMR spectra of Azo-SEP in DMF-d7 before (Black), after UV irradiation (red), and after a subsequent UV and visible light irradiation cycle (blue).
Figure S14. UV-Vis spectra of Azo-SEP before and after phase transfer in a) toluene and b) H2O/DMF (1:1 in volume ratio) mixed solution upon UV and visible light irradiations. (red line: encountering one cycle, blue dash: encountering ten cycles of UV and visible light irradiations). According to the UV-Vis spectra (Figure S14), the phase transfer efficiency of Azo-SEP is about 96−98%.
S10
Figure S15. 1H NMR spectrum of toluene phase separated from H2O/DMF (1:1 in volume ratio) in CDCl3. From the calculation of integral values belonging to DMF and toluene, about 4.7% of DMF can be confirmed to exist in toluene phase.
Figure S16. 1H NMR spectrum of toluene phase separated from H2O/DMF (3:2 in volume ratio) in CDCl3. From the calculation of integral values belonging to DMF and toluene, about 2.9% of DMF can be confirmed to exist in toluene phase.
S11
Figure S17. 1H NMR spectrum of toluene phase separated from H2O/DMF (2:1 in volume ratio) in CDCl3. From the calculation of integral values belonging to DMF and toluene, about 1.9% of DMF can be confirmed to exist in toluene phase.
Figure S18. 1H NMR spectrum of H2O/DMF (1:1 in volume ratio) phase in DMSO-d6 after the oxidation reaction. From the calculation of integral values belonging to DMF and toluene, about 2.5% of toluene exists in H2O/DMF phase, while the oxidized product was not found in H2O/DMF phase.
S12
Figure S19. 1H NMR spectrum of H2O/DMF (3:2 in volume ratio) phase in DMSO-d6. From the calculation of integral values belonging to DMF and toluene, about 1.3% of toluene exists in H2O/DMF phase.
Figure S20. 1H NMR spectrum of H2O/DMF (2:1 in volume ratio) phase in DMSO-d6. From the calculation of integral values belonging to DMF and toluene, about 1.0% of toluene exists in H2O/DMF phase.
S13
Figure S21. Plots of the absorbance at 306 nm of PH in toluene solution under the condition of catalysis oxidition reaction of Azo-SEP summarized from UV-Vis spectra versus the time.
Figure S22. 1H NMR spectra of the substrate and product after 4 h reaction in DMSO-d6.
S14
Figure S23. UV-Vis spectrum of H2O/DMF phase after subsequent UV and visible light induced phase transfer.
Figure S24. FT-IR spectra of Azo-SEP in KBr pellets before and after five cycles of oxidation reaction.
S15
Figure S25. 1H NMR spectra of Azo-SEP in DMF-d7 before and after five cycles of oxidation reaction.
Figure S26. UV-Vis spectra of Azo-SEP in toluene in the initail state (blue) and upon five recycles (red) with the same H2O/DMF (2:1 in volume ratio) extraction solvent. According to the UV-Vis spectra (Figure S26), the recovered Azo-SEP is about 92.7% of its initial state.
S16
Figure S27. 1H NMR spectra of the products under the concentrations of 1.0×10–4 (black), 5.0×10–5 (red), 1.0×10–5 mmol (blue) of catalyst in DMSO-d6 after 4 h of reaction, and 1.0×10–4 mmol (green) of catalyst upon five recycles with new H2O/DMF (1:1 in volume ratio) extraction solvents after 4 h of reaction. The NMR spectra in Figure S27 show that after 4 h of reaction the mole ratios of sulfoxide to sulfone (SO:SO2, %) are 1:99, 30:70 and 40:60 for 1.0×10–4, 5.0×10–5 and 1.0×10–5 mmol of catalyst, respectively. The product selectivity for sulfone becomes poorer as the amount of POM catalyst decreases. For 1.0×10–4 mmol of catalyst, upon five recycles, the conversion still maintains 100% while the selectivity for sulfone becomes 12:88.
Figure S28. Digital photographs of reversible phase transfer of (Mo132) complex upon a) visible and b) UV light irradiations, and (P5W30) complex upon c) visible and d) UV light irradiations between toluene and H2O/DMF (1:1 in volume ratio) mixed solution.
S17
Figure S29. UV-Vis spectra of PH oxidition reaction in toluene solution under the catalysis of P5W30 complex. The reaction solution has been diluted 40 folds of reaction solution.
REFERENCES (1) Tourné, C. M.; Tourné, G. F.; Zonnevijlle, F. J. Chem. Soc., Dalton Trans. 1991, 143. (2) Creaser, I.; Heckel, M. C.; Neitz, R. J.; Pope, M. T. Inorg. Chem.1993, 32, 1573. (3) Mller, A.; Krickemeyer, E.; Bgge, H.; Schmidtmann, M.; Peter, F. Angew. Chem. Int. Ed. 1998, 37, 3360. (4) Yang, Y.; Yue, L.; Li, H.; Maher, E.; Li, Y.; Wang, Y.; Wu, L.; Yam, V. W.-W. Small 2012, 8, 3105.
S18
Materials.
Na12[WZn3(H2O)2(ZnW9O34)2]
(Zn5W19O68),
(NH4)72{(Mo)Mo5O21(H2O)6}12{Mo2O4(SO4)}30 (Mo132) and K12.5Na1.5[NaP5W30O110] (P5W30) were freshly prepared according to the literature.1-3 Phenothiazine was purchased from Sinopharm Chemical Reagent Co. Ltd. Cumyl hydroperoxide was the product of Aladdin Chemistry Co. Ltd. All the compounds were used without further purification, and all the used solvents were analytical grade. Doubly distilled water was used in the experiments. Silica gel (100-200 mesh) was applied for column chromatography. The quaternary ammonium bearing azobenzene (Azo) groups at the end of tails, Azo-ended surfactant (AzoC6)2N, and 1-(4-(6-bromohexy)phenyl)-2-phenyldiazene (1) was synthesized according to the literature.4 The surfactant (AzoC6)(C4)N was synthesized and the detailed synthetic procedures are described in Scheme S1. The chemical structure of surfactant (AzoC6)(C4)N was confirmed by 1H NMR.
Scheme S1. Synthetic route of surfactant (AzoC6)(C4)N. S1
(AzoC6)(C4)N: A mixture of (1) (2.0 g, 5.5 mmol), 1-butanamine (2.8 g, 38.3 mmol) in ethanol (50 mL) was refluxed for 24 h. After the solvent was evaporated, the reaction mixture was purified by recrystallization in anhydrous diethyl ether, giving a yellow solid. (yield: 2.1 g, 87.5%). 1H NMR (CDCl3, TMS): δ = 0.951 (t, J = 7.5 Hz, 3H), 1.485 (m, 6H), 1.904 (m, 6H), 2.955 (m, 4H), 4.019 (t, J = 6.5 Hz, 2H), 6.972 (d, J = 8.5 Hz, 2H), 7.429 (t, J = 8 Hz, 2H), 7.494 (t, J = 8 Hz, 2H), 7.874 (d, J = 8 Hz, 2H), 7.891 (d, J = 8.5 Hz, 2H).
Characterization of POM complexes. The chemical composition of the Azo-SEP with Azo groups on the periphery was confirmed by
1
H NMR, FT-IR, elemental analysis, and
1
thermogravimetric (TG) measurements. H NMR (CDCl3, TMS): δ = 1.312 (m, 16H), 3.296 (s, 6H), 3.536 (s, 4H), 3.936 (s, 4H), 6.990 (d, J = 7.5 Hz, 4H), 7.373 (t, J = 7.0 Hz, 2H), 7.435 (t, J = 7.5 Hz, 4H), 7.831 (m, 8H). 1H NMR (DMF-d7/D2O (1:1 in volume ratio), TMS): δ = 1.590 (m, 16H), 3.324 (s, 6H), 3.537 (s, 4H), 4.104 (s, 4H), 7.018 (m, 12H), 7.388 (s, 2H), 7.524 (s, 4H). FT-IR (KBr): ν = 3431, 2941, 2866, 1600, 1581, 1501, 1472, 1389, 1300, 1254, 1142, 920, 874, 839, 768, 723 cm–1. Anal. Calcd for Azo-SEP (C342H436N45O88W19Zn5Na3, 10474.25): C 39.22, H 4.20, N 6.02. Found: C 39.65, H 4.25, N 6.04, corresponding to the chemical formula: [(AzoC6)2N]9Na3[WZn3(H2O)2(ZnW9O34)2] (10474.25). The TG measurement suggests a 53.5% (in w/w) of mass loss at the temperature between 40 and 700 °C. The MALDI-TOF result around 10475 proves the proposed chemical formula. The chemical compositions of (Mo132) and (P5W30) complexes were charaterized by elemental analysis. Anal. Calcd for (Mo132) complex (C1254H2080N204O728S30Mo132, 45288.93): C 33.26, H 4.63, N 6.31. Found: C 33.35, H 4.55, N 6.12, corresponding
to
the
chemical
formula:
[(AzoC6)2N]33(NH4)39(H2O)48Mo132O372(H2O)72(SO4)30(H2O)50 (45288.93). Anal. Calcd for (P5W30) complexes (C286H416N39O123W30P5Na2 or C286H416N39O123W30P5NaK, 12084.60 or 12100.71): C 28.43 or 28.39, H 3.47 or 3.47, N 4.52 or 4.51. Found: C 28.71, H 3.45, N 4.48, corresponding to the chemical formula: [(AzoC6)(C4)N]13Na[NaP5W30O110] (12084.60) or [(AzoC6)(C4)N]13K [NaP5W30O110] (12100.71).
Catalytic Procedure: Azo-SEP (1.0×10–4 mmol), 80-85% CHP (0.1 mmol) and PH (1.0×10–2 mmol) were dissolved in toluene (2 mL) in a 10 mL flask and stirred (1000 r min–1) at 30 °C for a certain period time. The reaction progress was monitored by TLC and UV-Vis. After the reaction, H2O/DMF mixed solvents (2 mL) was added, and the solution was irradiated by UV light to trigger the phase transfer of Azo-SEP to H2O/DMF phase. After phase separation, the Azo-SEP catalyst was recovered upon visible light irradiation, which induced the phase transfer of the catalyst back to toluene phase. S2
Photo-irradiation. For UV irradiation of the Azo-SEP solution (3.0 mL) sealed in a quartz cell, WHF 203 UV lamp (365 nm) was used. For visible light irradiation, 200-W incandescent light bulb (>440 nm) was applied. The irradiation time is limited in 10 min and distance between the light source and sample is kept at 10 cm.
Measurements. 1H NMR spectra were recorded on a Bruker Avance 500 instrument using TMS as internal reference. Fourier transform infrared (FT-IR) spectral measurement on pressed KBr pellets was performed on a Bruker IFS66v FT-IR spectrometer equipped with a DGTS detector (32 scans) with a resolution of 4 cm–1. Organic elemental analysis (C, H, N) was carried out on a Flash EA1112 analyzer from ThermoQuest Italia S.P.A., while inorganic elemental analysis (W) was performed on a POEMS inductively coupled plasma atomic emission spectrometer (ICP-AES) (TJA, USA). Thermogravimetric (TG) thermograms were conducted on a Perkin-Elmer Diamond TG/DTA instrument with a heating rate of 10 °C min–1 under flowing air. Matrix-assisted laser desorption/ionization time-of-flight mass spectrum (MALDI-TOF) mass spectrum was recorded on an autoflex TOF/TOF (Bruker, Germany) mass spectrometer, equipped with a nitrogen laser (337 nm, 3 ns pulse), and operated in the positive ion reflector mode with a detector potential of -4.75 kV. The matrix DCTB was employed. The mass range for data acquisition is from m/z 2000 to 14000 Da. X-ray photoelectron spectroscopy (XPS) was performed on an ESCALAB 250 spectrometer with a monochromic X-ray source (AlKa line, 1486.6 eV) and the charging shift was corrected by the binding energy of C(1s) at 284.6 eV. UV-Vis spectra were performed on a Shimadzu UV-3600 Spectrophotometer. Transmission electron microscopy (TEM) images were obtained with a Hitachi H8100 electron microscope with accelerating voltage of 200 KV without staining. Scanning electron microscopic (SEM) measurement was performed on a JEOL JSM–6700F field emission scanning electron microscope. Dynamic light scattering (DLS) measurements were done using a Zetasizer NanoZS (Malvern Instruments). The HPLC analysis was performed on SHIMADZU LC-20A with an Aglient ZORBAX SB-C18 column (d = 5 μm, l = 250 mm) at 40 °C. The eluent was methanol/H2O (70:30) at a flow rate of 1 mL min–1.
S3
Supplement Data.
Figure S1. 1H NMR spectrum of (AzoC6)(C4)N in CDCl3. The letters without prime correspond to the tans- form, and the letters with prime ascribe to the cis- form.
Figure S2. TG curve of Azo-SEP, which was carried out in air with a heating rate of 10 °C –1
min .
S4
Figure S3. 1H NMR spectra of (AzoC6)2N and Azo-SEP in CDCl3.
Figure S4. 1H NMR spectra of cis-(AzoC6)2N and cis-Azo-SEP in D2O/DMF-d7 (1:1 in volume ratio).
S5
Figure S5. FT-IR spectra of pure Zn5W19O68, (AzoC6)2N, and Azo-SEP in KBr pellets. Table S1. The Assignments for Characteristic Vibrations of (AzoC6)2N, POM, and Azo-SEP in FT-IR Spectra. (AzoC6)2N (cm–1)
Azo-SEP (cm–1)
Zn5W19O68 (cm–1)
3422
3431
3398
O–H asym. str.
2947
2941
-
CH3 asym. str.
2870
2866
-
CH2 sym. str.
-
-
1622
1605 1582 1502
1600 1581 1501
-
C=C framework str.
1474
1472
-
CH2N scissoring
1394
1389
-
CH3 scissoring
1302
1300
-
CH2 wagging
1256
1254
-
=C–O–C asym. str.
1146
1142
-
C–N str.
1057
-
-
=C–O–C asym. str.
-
920
926
W–Od asym. str.
-
874
881
W–Ob–W asym. str.
835
839
-
-
768
770
723
723
-
Assignments[a]
O–H scissoring
C–H str. W–Oc–W asym. str. CH2 rocking
[a] Asym. str., antisymmetrical stretching; sym. str., symmetrical stretching. S6
Figure S6. MALDI-TOF mass spectrum of Azo-SEP. The
central
peak
around
10475
corresponds
to
the
chemical
formula
of
[(AzoC6)2N]9Na3[Zn5W19O68], while the peak at 9892 is in agreement with the formula of [(AzoC6)2N]8Na4[Zn5W19O68], and the peak at 11082 is coincident to the formula of [(AzoC6)2N]10Na2[Zn5W19O68]·Na+. The datum reveals that the obtained complex has an average chemical formula of [(AzoC6)2N]9Na3[Zn5W19O68] (10474.25).
Figure S7. W(4f) XPS spectra of Azo-SEP before (black) and after 5 cycles of UV and visible light irradiations (red).
S7
Figure S8. DLS diagrams of Azo-SEP in a) toluene solution, and b) H2O/DMF mixed solution. Insets: corresponding photographs of Azo-SEP solutions upon UV and visible light irradiations.
Figure S9. a) TEM image of Azo-SEP in toluene solution before UV irradiation, b) SEM image after UV irradiation, and c) TEM image after a subsequent UV and visible light irradiation cycle; and d) SEM image of Azo-SEP in H2O/DMF mixed solution before UV irradiation, e) TEM image after UV irradiation, and f) SEM image after a subsequent UV and visible light irradiation cycle.
S8
Figure S10. UV-Vis spectra of Azo-SEP in a) toluene and b) H2O/DMF mixed solvents encountering alternate UV and visible light irradiations. (Black line: initial state, red line: encountering one cycle, blue dash: encountering ten cycles of UV and visible light irradiations)
Figure S11. UV-Vis spectra of Azo-SEP in toluene upon a) UV and b) visible light irradiation, and in H2O/DMF upon c) UV and d) visible light irradiation.
S9
Figure S12. Plots of absorbance of Azo-SEP in a) toluene at 349 nm, and in b) H2O/DMF at 348 nm upon UV and visible light irradiation, summarized from UV-Vis spectra versus the time.
Figure S13. 1H NMR spectra of Azo-SEP in DMF-d7 before (Black), after UV irradiation (red), and after a subsequent UV and visible light irradiation cycle (blue).
Figure S14. UV-Vis spectra of Azo-SEP before and after phase transfer in a) toluene and b) H2O/DMF (1:1 in volume ratio) mixed solution upon UV and visible light irradiations. (red line: encountering one cycle, blue dash: encountering ten cycles of UV and visible light irradiations). According to the UV-Vis spectra (Figure S14), the phase transfer efficiency of Azo-SEP is about 96−98%.
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Figure S15. 1H NMR spectrum of toluene phase separated from H2O/DMF (1:1 in volume ratio) in CDCl3. From the calculation of integral values belonging to DMF and toluene, about 4.7% of DMF can be confirmed to exist in toluene phase.
Figure S16. 1H NMR spectrum of toluene phase separated from H2O/DMF (3:2 in volume ratio) in CDCl3. From the calculation of integral values belonging to DMF and toluene, about 2.9% of DMF can be confirmed to exist in toluene phase.
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Figure S17. 1H NMR spectrum of toluene phase separated from H2O/DMF (2:1 in volume ratio) in CDCl3. From the calculation of integral values belonging to DMF and toluene, about 1.9% of DMF can be confirmed to exist in toluene phase.
Figure S18. 1H NMR spectrum of H2O/DMF (1:1 in volume ratio) phase in DMSO-d6 after the oxidation reaction. From the calculation of integral values belonging to DMF and toluene, about 2.5% of toluene exists in H2O/DMF phase, while the oxidized product was not found in H2O/DMF phase.
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Figure S19. 1H NMR spectrum of H2O/DMF (3:2 in volume ratio) phase in DMSO-d6. From the calculation of integral values belonging to DMF and toluene, about 1.3% of toluene exists in H2O/DMF phase.
Figure S20. 1H NMR spectrum of H2O/DMF (2:1 in volume ratio) phase in DMSO-d6. From the calculation of integral values belonging to DMF and toluene, about 1.0% of toluene exists in H2O/DMF phase.
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Figure S21. Plots of the absorbance at 306 nm of PH in toluene solution under the condition of catalysis oxidition reaction of Azo-SEP summarized from UV-Vis spectra versus the time.
Figure S22. 1H NMR spectra of the substrate and product after 4 h reaction in DMSO-d6.
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Figure S23. UV-Vis spectrum of H2O/DMF phase after subsequent UV and visible light induced phase transfer.
Figure S24. FT-IR spectra of Azo-SEP in KBr pellets before and after five cycles of oxidation reaction.
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Figure S25. 1H NMR spectra of Azo-SEP in DMF-d7 before and after five cycles of oxidation reaction.
Figure S26. UV-Vis spectra of Azo-SEP in toluene in the initail state (blue) and upon five recycles (red) with the same H2O/DMF (2:1 in volume ratio) extraction solvent. According to the UV-Vis spectra (Figure S26), the recovered Azo-SEP is about 92.7% of its initial state.
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Figure S27. 1H NMR spectra of the products under the concentrations of 1.0×10–4 (black), 5.0×10–5 (red), 1.0×10–5 mmol (blue) of catalyst in DMSO-d6 after 4 h of reaction, and 1.0×10–4 mmol (green) of catalyst upon five recycles with new H2O/DMF (1:1 in volume ratio) extraction solvents after 4 h of reaction. The NMR spectra in Figure S27 show that after 4 h of reaction the mole ratios of sulfoxide to sulfone (SO:SO2, %) are 1:99, 30:70 and 40:60 for 1.0×10–4, 5.0×10–5 and 1.0×10–5 mmol of catalyst, respectively. The product selectivity for sulfone becomes poorer as the amount of POM catalyst decreases. For 1.0×10–4 mmol of catalyst, upon five recycles, the conversion still maintains 100% while the selectivity for sulfone becomes 12:88.
Figure S28. Digital photographs of reversible phase transfer of (Mo132) complex upon a) visible and b) UV light irradiations, and (P5W30) complex upon c) visible and d) UV light irradiations between toluene and H2O/DMF (1:1 in volume ratio) mixed solution.
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Figure S29. UV-Vis spectra of PH oxidition reaction in toluene solution under the catalysis of P5W30 complex. The reaction solution has been diluted 40 folds of reaction solution.
REFERENCES (1) Tourné, C. M.; Tourné, G. F.; Zonnevijlle, F. J. Chem. Soc., Dalton Trans. 1991, 143. (2) Creaser, I.; Heckel, M. C.; Neitz, R. J.; Pope, M. T. Inorg. Chem.1993, 32, 1573. (3) Mller, A.; Krickemeyer, E.; Bgge, H.; Schmidtmann, M.; Peter, F. Angew. Chem. Int. Ed. 1998, 37, 3360. (4) Yang, Y.; Yue, L.; Li, H.; Maher, E.; Li, Y.; Wang, Y.; Wu, L.; Yam, V. W.-W. Small 2012, 8, 3105.
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