Supporting Information

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1 Supporting Information Tunable Luminescent Lanthanide Supramolecular Assembly Based on Photoreaction of Anthracene Yan Zhou, a Heng-Yi Zhang, a,b Zhi-Yuan Zhang, a and Yu Liu* a,b a Department of Chemistry, State Key Laboratory of Elemento-rganic Chemistry, (Tianjin), ankai University, Tianjin , P. R. China b Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) ankai University, Tianjin (P. R. China) yuliu@nankai.edu.cn S1

2 Table of Contents 1. Synthesis and characterization of compounds. 2. Job plot for host molecular 1 and Eu(Tf) The TEM image of compound 1 with Ln 3+. S3-S17 S17 S18 4. H MR spectra of 1 and Eu(Tf) 3. S18 5. The optical properties of 2 with Ln 3+ and the TEM image of compound 2 with Ln 3+. S18-S20 6. Fluorescence spectra of compound 3 after adding Eu 3+ and Tb 3+. S21-S H MR spectra monitoring the reversible photo-oxygenation of host molecular 1. S23 8. Absorption spectra, fluorescence spectra of compound 1 after irradiation with UV light at 365 nm. S23 9. MALDI-TF mass spectra of host molecular 1 after irradiation with UV light at 365 nm. S24-S The optical properties of 1 EP with Ln 3+ in PMMA and the TEM image of 1 EP with Ln The influence on luminescence of the Ln 3+ after adding the alkali and alkaline earth metal ions. S The thermal stability of 1 EP in solution was investigated by 1 H MR spectra and MALDI-TF mass spectra. S28 S26 S2

3 H H B H H B CH + 1) ah, EtH 2)H 4 H 6 CH 3 CH 2 H a 2 Cr 2 7 H 2 S 4 CH 3 CH Zn ah Br 2 CCl 4 Br Br BBr 3 H Br H Cs 2 C 3,DMF Br CH 2 Cl 2 H Br H Ts Ts 5 4 Br Br Br H H B Pd(PPh 3 ) 4,a 2 C 3 + CH 3 H,Toluene,reflux Br + Br CH ah,h 4 H EtH 10 BS, AIB CCl 4,reflux B H 8 K 2 C 3 CH 3 C,reflux 7 B B Br Br + Pd(PPh 3 ) 4,a 2 C 3 CH 3 H,Toluene,reflux 2 Compound12,Pd(PPh 3 ) 4,a 2 C 3 CH 3 H,Toluene,reflux Br 11 3 Scheme 1. Synthesis pathway of compounds 1, 2 and 3. S3

4 Experimental Section General Methods. All chemicals were commercially available unless noted otherwise. Compounds 6 1, 5 2, 9 3, 11 4 were prepared according to the literatures procedure. Compound 8 was purchased from TCI. MR spectra were recorded on a Varian Mercury VX400 instrument. The optical switch experiments were carried out using a photochemical reaction apparatus with a 500W Hg lamp. Fluorescence spectra were performed on an F-4500 spectrofluorometer (Hitachi, Tokyo, Japan) equipped with a plotter unit and a quartz cell (1 cm 1 cm). Quantum yield and fluorescence life times were recorded in a conventional quartz cell ( mm) at 25 C on a spectrometer employing the single photon counting technique. Photoluminescent measurements were taken at an excitation wavelength of 365 nm. The slit width was 10 and 10 nm for excitation and emission, respectively. The fluorescence quantum yield was measured with an Edinburgh Analytical Instruments FLS920 spectrometer (Edinburgh Instruments, Edinburgh, U.K.) employing the time correlated single photon counting technique. Preparation of 4: Cesium carbonate (5.22 g, 16 mmol) was placed in a 500 ml round-bottomed flask fitted with condenser and pressure-equalized dropping funnel. The system was flushed with 2, and anhydrous DMF (200 ml) was added to the flask. The suspension in the flask was heated to 110 C while stirring. The compound 5 (796 mg, 2.0 mmol) and ditosylate (5.96 g, 4.0 mmol) were dissolved in DMF (160 ml) and added to the dropping funnel. Then the solution was added dropwise over 24 h. This S4

5 mixture was stirred at 110 C, under an 2 atmosphere, for a further 3 d. Subsequently, the solvent was removed in vacuo. and the residue was partitioned between CH 2 Cl 2 (100 ml) and H 2 (100 ml) and the aqueous layer was extracted with CH 2 Cl 2 (3 50 ml). The organic phase was dried (MgS 4 ), and the solvents were removed in vacuo. The residue was subjected to column chromatography (Si 2 : gradient elution with CH 2 Cl 2 / CH 3 H, (50:1) to yield the desired compound 4 as a white solid (861 mg, 40%). 1 H MR (400 MHz, CDCl 3 ) δ 7.65 (s, 4H), 6.85 (s, 8H), (m, 48H). HRMS (MALDI) m/z (M+a + ) calcd for C 50 H abr + 2 : Found: Preparation of 1: A three neck flask was charged with 6 (393.6 mg, 1.11 mmol), 4 (300 mg, 0.28 mmol), a 2 C 3 (177.2 mg, 1.68 mmol), toluene (26 ml) and CH 3 H (37 ml), and the resulting solution was degassed via three freeze-pump-thaw cycles. Pd(PPh 3 ) 4 (32.2 mg, mmol) was then added under an argon atmosphere. The mixture was refluxed for about 48 h (monitored by TLC) resulting in a turbid solution. After removed the solvents under vacuum, CHCl 3 (50 ml) was added and washed with H 2, respectively. The organic layer was dried with anhydrous a 2 S 4 and filtered. After removal of CHCl 3 under vacuum, the residue was purified by column chromatography on alumina with CH 2 Cl 2 / CH 3 H (100:1) as eluent to give light yellow solid (257.7 mg, 60 %). 1 H MR (400 MHz, CDCl 3 ) δ 8.91 (s, 4H), 8.78 (s, 4H), 8.74 (d, J = 7.8 Hz, 4H), 8.13 (d, J = 7.4 Hz, 4H), 7.93 (t, J = 7.3 Hz, 4H), 7.61 (d, J = 7.4 Hz, 4H), 7.40 (s, 4H), 6.86 (s, 12H), 4.13 (s, 8H), 4.03 (s, 8H), 3.91 (s, 16H), 3.82 (s, 16H). 13 C S5

6 MR (100 MHz, CDCl 3 ) δ , , , , , , , , , , , , , , , , , , , 71.40, 71.30, 69.95, 69.44, HRMS (MALDI) m/z (M+H + ) calcd for C 92 H : Found: Preparation of 7: A two neck flask was charged with 9 (602 g, 2.74 mmol), 8 (1 g, 2.49 mmol), K 2 C 3 (755.8 mg, 5.47 mmol) and CH 3 C (30 ml). The system was flushed with 2, the mixture was refluxed for about 24 h. After removed the solvents under vacuum, CH 2 Cl 2 (50 ml) was added and washed with H 2, respectively. The organic layer was dried with anhydrous a 2 S 4 and filtered. After removal of CH 2 Cl 2 under vacuum, the residue was purified by column chromatography on alumina with CH 2 Cl 2 / CH 3 H (100:1) as eluent to give white solid (876.3 mg, 65 %). 1 H MR (400 MHz, d 6 -DMS) δ 8.76 (d, J = 3.9 Hz, 2H), 8.71 (s, 2H), 8.66 (d, J = 7.9 Hz, 2H), (m, 2H), 7.94 (d, J = 8.2 Hz, 2H), 7.64 (dd, J = 8.3, 2.5 Hz, 4H), (m, 2H), 7.06 (d, J = 8.5 Hz, 2H), 5.24 (s, 2H), 1.27 (s, 12H). HRMS (MALDI) m/z (M+H + ) calcd for C 34 H 33 B : Found: Preparation of 2: A three neck flask was charged with 4 (300 mg, 0.28 mmol), 7 (603.4 mg, 1.11 mmol), a 2 C 3 (177.2 mg, 1.68 mmol), toluene (26 ml) and CH 3 H (37 ml), and the resulting solution was degassed via three freeze-pump-thaw cycles. Pd(PPh 3 ) 4 (32.2 mg, mmol) was then added under an argon atmosphere. The mixture was refluxed for about 48 h (monitored by TLC) resulting in a turbid solution. After S6

7 removed the solvents under vacuum, CHCl 3 (50 ml) was added and washed with H 2, respectively. The organic layer was dried with anhydrous a 2 S 4 and filtered. After removal of CHCl 3 under vacuum, the residue was purified by column chromatography on alumina with CH 2 Cl 2 / CH 3 H (100:1) as eluent to give light yellow solid (205.3 mg, 42 %). 1 H MR (400 MHz, CDCl 3 ) δ 8.80 (s, 4H), 8.75 (d, J = 6.0 Hz, 4H), 8.70 (d, J = 8.0 Hz, 4H), 8.01 (d, J = 8.2 Hz, 4H), 7.90 (td, J = 7.7, 1.7 Hz, 4H), 7.72 (d, J = 8.2 Hz, 4H), 7.37 (dd, J = 7.0, 5.4 Hz, 8H), 7.23 (d, J = 8.6 Hz, 4H), (m, 12H), 5.29 (s, 4H), (m, 8H), 4.00 (s, 8H), 3.89 (s, 16H), 3.81 (d, J = 6.5 Hz, 16H). 13 C MR (100 MHz, CDCl 3 ) δ , , , , , , , , , , , , , , , , , , , , , , 71.31, 71.23, 69.93, 69.82, 69.43, HRMS (MALDI) m/z (M+a + ) calcd for C 106 H a + : Found: Preparation of 3: A three neck flask was charged with 11 (300 mg, 1.17 mmol), 6 (826.4 mg, 2.34 mmol), a 2 C 3 (744.0 mg, 7.02 mmol), toluene (26 ml) and CH 3 H (37 ml), and the resulting solution was degassed via three freeze-pump-thaw cycles. Pd(PPh 3 ) 4 (203.4 mg, mmol) was then added under an argon atmosphere. The mixture was refluxed for about 48 h (monitored by TLC) resulting in a turbid solution. After removed the solvents under vacuum, CHCl 3 (50 ml) was added and washed with H 2, respectively. The organic layer was dried with anhydrous a 2 S 4 and filtered. After removal of CHCl 3 under vacuum, the residue was purified by column chromatography S7

8 on alumina with CH 2 Cl 2 / CH 3 H (100:1) as eluent to give white solid (500 mg, 88 %). 1 H MR (400 MHz, CDCl 3 ) δ 8.89 (s, 2H), 8.73 (dd, J = 13.3, 6.1 Hz, 4H), 8.51 (s, 1H), 8.11 (d, J = 8.0 Hz, 2H), 8.05 (d, J = 8.5 Hz, 2H), 7.90 (t, J = 6.9 Hz, 2H), 7.71 (d, J = 8.7 Hz, 2H), 7.58 (d, J = 8.0 Hz, 2H), (m, 2H), 7.37 (dd, J = 13.0, 6.0 Hz, 4H). 13 C MR (100 MHz, CDCl 3 ) δ , , , , , , , , , , , , , , , , , , , HRMS (MALDI) m/z (M+H + ) calcd for C 35 H : Found: S8

9 Figure S1. 1 H MR spectra (400 MHz, 298 K) of the compound 10. Figure S2. MALDI-TF mass spectrum of compound 10. S9

10 Figure S3. 1 H MR spectrum of 4 (400 MHz, CDCl 3, 298 K). Figure S4. MALDI-TF mass spectrum of compound 4. S10

11 Figure S5. 1 H MR spectrum of 1 (400 MHz, CDCl 3, 298 K). Figure S6. 13 C MR spectrum of 1 (100 MHz, CDCl 3, 298 K). S11

12 Figure S7. MALDI-TF mass spectrum of compound 1. Figure S8. The 1 H- 1 H CSY spectrum of 1. S12

13 Figure S9. 1 H MR spectrum of 7 (400 MHz, d 6 -DMS, 298 K). Figure S10. MALDI-TF mass spectrum of compound 7. S13

14 Figure S11. 1 H MR spectrum of 2 (400 MHz, CDCl 3, 298 K). Figure S C MR spectrum of 2 (100 MHz, CDCl 3, 298 K). S14

15 Figure S13. MALDI-TF mass spectrum of compound 2. Figure S14. 1 H MR spectrum of 11 (400 MHz, CDCl 3, 298 K). S15

16 Figure S15. 1 H MR spectrum of 3 (400 MHz, CDCl 3, 298 K). Figure S C MR spectrum of 3 (100 MHz, CDCl 3, 298 K). S16

17 Figure S17. MALDI-TF mass spectrum of compound 3. Figure S18. Job plot for host molecular 1 and Eu(Tf) 3. Fluorescence changes recorded at 495 nm for 1. The sum of the total concentrations of hosts and guests is constant (0.01 mm) in CHCl 3 /CH 3 C (1:1, v/v) solution. S17

18 Figure S19. TEM images of 1 (a) free 1, (b) 1 + Eu 3+ and Tb 3+, inset: magnified TEM image (scale bar = 500 nm), (c) DLS results of 1/Eu 3+ system. Figure S20. Partial 1 H MR spectra (400 MHz, 1:1CDCl 3 -CD 3 C, 293 K) of (a) 1 and (b) addition of 1.2 equiv of Eu(Tf) 3 to 1 ([1] = 0.5 mm). We found that incremental addition of Eu(Tf) 3 and Tb(Tf) 3 to 2 (in CHCl 3 /CH 3 C, 1:1 v/v) up to a tpy:ln 3+ ratio of 2:1 can give rise to a red-emissive (Figure S21a) and green-emissive solution respectively (Figure S21b). Furthermore, the addition of the equimolar Eu 3+ :Tb 3+ led to a pale-yellow-emissive solution (Figure S21c). Interestingly, the emission of compound 2 at 460 nm, which could be considered as combined emission from ant and tpy, was not suppressed completely after the addition of Eu 3+ or Tb 3+ ions (Figure S21). This residual emission should be attributed to the central ant core, which probably did t involve in sensitization of Eu 3+ due to the large spatial distance between ant and the metal ion. As shown in Figure S22, the anthracene unit in reference compound 2 can undergo a photoreaction (Figure S22a), and the Eu 2 EP could also exhibit satisfactory luminescence (Figure S22b). However, because the reference compound 2 possesses a non-conjugated link between anthracene and terpyridine, the reference dyad lanthanide metal complex can exhibit excellent luminescence properties through the intramolecular energy transfer from the excited terpyridine unit to Ln 3+ without affected by anthracene unit. S18

19 Therefore, the reference metal complex can t be used as a smart device to switch on/off the luminescence of Ln 2 by a photoreaction from anthracene unit. In addition, we also explored the morphological information of the Ln 2 nanoarchitecture using TEM observations. The complex Eu 2 and Tb 2 revealed the nanorings and nanofibrous morphology, respectively (Figure S23). It was quite unexpected that the nanorings were observed based on the self-assembly of the Eu 2. which may be developed on deposits. To further investigate potential applications of the Ln 2 complexes as light-emitting materials, we embedded the Ln 2 complexes into poly(methyl methacrylate) (PMMA) and then the resultant mixtures were subjected to spin-coating. The spin-coated films were found to exhibit excellent and characteristic lanthanide luminescence in the solid state similar to that observed in solution (Figure S24 and Figure S25), indicative of utmost importance to their practical applications. The control experiments suggested that the properties of the terpyridine group vary drastically in the large aromatic conjugation system of 1, causing a mismatch between the lowest triplet state of ligand 1 and the first excited lanthanide state. Figure S21. (a) Eu 2, (b) Tb 2, and (c) EuTb 2 (λ ex = 290 nm) ([2] = 0.01 mm). Inset photo image of fluorescence changes of 2 upon addition of Eu 3+ or Tb 3+ in CH 3 C/CHCl 3 (1:1, v/v) solution. Figure S22. (a) Fluorescence changes of 2 ([2] = 0.01 mm) under UV light irradiation (365 nm), (b) Eu 2 EP. Inset pictures show the emission color change in CH 3 C/CHCl 3 (1:1, v/v) solution. S19

20 Figure S23. The TEM image of reference compound 2 with Ln 3+ : (a) 2 + Eu 3+, and (b) 2 + Tb 3+ (scale bar = 500 nm). Figure S24. The spin-coated films of compound 2 with Ln 3+ mixed with PMMA (5 wt %) irradiated under UV light: (a) free 2, (b) 2 + Eu 3+, (c) 2 + Tb 3+, and (d) 2 + Eu 3+ +Tb 3+. Figure S25. Emission spectra of (a) 2, (b) Eu 2, (c) Tb 2, (d) EuTb 2 (λ ex = 340 nm) in PMMA films. S20

21 Furthermore, control experiments using 3 were performed. We found that incremental addition of Eu 3+ to 3 (in CHCl 3 /CH 3 C, 1:1 v/v) up to a tpy:ln 3+ ratio of 2:1 can give rise to a new peak at 616 nm, which should be assigned to the emission of Eu 3 (Figure S26a). Similarly, After adding Tb 3+ into 3, the new peak at 545 nm appears, which should be assigned to the emission of Tb 3 (Figure S26b). These observations suggest that the Ln 3+ can be sensitized by the ligand 3 to some extent. but it is not a good sensitizer, especially for Tb 3+. ne reasonable explanation is that the aromatic conjugation system containing both anthracene and terpyridine group may cause the large energy difference between the ligand and the lanthanide ions. Figure S26. (a) Eu 3, (b) Tb 3 (λ ex = 300 nm) in CH 3 C/CHCl 3 (1:1, v/v) solution ([3] = 0.01 mm) (λ ex = 300 nm). Inset photo image of fluorescence changes of 3 upon addition of Eu 3+ or Tb 3+. In addition, we also investigated the photooxygenation process of anthracene of compound 3 by UV-vis absorption measurements, fluorescence spectrum. The absorption of the anthracene moiety in the range of nm vanishes gradually after irradiation by UV light at 365 nm for 5 min, implying that the anthracene chromophore could be destroyed (Figure S27a). Comparatively, the corresponding emission spectra of 3 (λ ex = 365 nm) show a decrease in intensity at 428 nm with the concomitant appearance of peak at 490 nm after 5 min of irradiation at 365 nm (Figure S27b). This observation indicates that the anthracene chromophore could undergo a photoreaction. Further investigation shows that incremental addition of Eu 3+ and Tb 3+ to 3 EP (in CHCl 3 /CH 3 C, 1:1 v/v) up to a tpy:ln 3+ ratio of 2:1 can give rise to a red-emissive for Eu 3+ (Figure S27c) and green-emissive for Tb 3+ (Figure S27d), respectively. The excellent luminescence properties should be benefited from intramolecular energy transfer (ET) from the excited terpyridine moiety to Ln 3+. S21

22 Figure S27. (a) Absorption spectra variation of 3 ([3] = 0.01 mm) upon irradiation by UV light (365 nm). (b) Fluorescence changes of 3 ([3] = 0.01 mm) under UV light irradiation (365 nm) (λ ex = 365 nm). Inset picture showed the fluorescence changes of 3 under UV light irradiation. Emission spectra of (c) Eu 3 EP, (d) Tb 3 EP. Inset photo image of fluorescence changes of 3 EP upon addition of Eu 3+ or Tb 3+ in CH 3 C/CHCl 3 (1:1, v/v) solution. (e) Reversible structural transformation of 3 by irradiation at 365 nm and heating. S22

23 Figure S28. 1 H MR spectra monitoring the reversible photo-oxygenation of host molecular 1 ([1] = 1 mm) in 2 atmosphere: (a) before irradiation with UV light, (b) after irradiation 100 s at 365 nm. Figure S29. (a) Absorption spectra variation of 1 ([1] = 0.01 mm) upon irradiation by UV light (365 nm). (b) Fluorescence changes of 1 ([1] = 0.01 mm) under UV light irradiation (365 nm). Inset picture showed the fluorescence changes of 1 under UV light irradiation. The compound 1 was excited at 365 nm resulting in strong emission with maxima at 500 nm which can be considered as emission from a large aromatic conjugation system comprised of ant and tpy, while the emission with maxima at 428 nm belonged to the emission from tpy merely. After UV light-induced ant-to-ep transition, large aromatic conjugation system was destroyed, with accompanying decrease of intensity at 500 nm and appearance of single emission of ant at 428 nm. S23

24 MALDI-TF-MS was performed to monitor the photooxygenation process. As shown in Figure S30a and Figure S30b, the peak m/z values at and assigned to the [M+H] + and [M+a] + of 1 were disappeared completely after UV irradiation at 365 nm. This results suggested that the anthracene unit in 1 had quantitatively been changed. The new peak m/z value at was formed, and it was assigned to the [M+H] + of 1 EP. The results indicated that the anthracene unit underwent a photooxygenation process and obtained the EP-form product. A very important aspect is that the photooxygenation of anthracene unit is reversible, as the EP-form products react back to the parent anthracenes under thermolysis. 5 When the 1 EP was heated at 50 C for 30 h or even longer time, the peak m/z value of [M+H] + of 1 was reappeared. However, the reverse process was not fully recover, there had a little of residual EP product (Figure S30c). The MALDI-TF-MS results also demonstrated that the anthracene core within the host molecule 1 could undergo reversible photooxygenation, which was basically consistent with the 1 H MR spectroscopy investigation results. S24

25 Figure S30. MALDI-TF mass spectra of host molecular 1: (a) before irradiation, (b) after irradiation at 365 nm for 100 s, and (c) after irradiation at 365 nm for 100 s and heating at 50 C for 30 h. S25

26 Figure S31. The TEM image of 1 EP with Ln 3+ : (a) 1 EP + Eu 3+, and (b) 1 EP + Tb 3+, and (c) 1 EP + Eu 3+ + Tb 3+ (scale bar = 500 nm). Figure S32. The spin-coated films of 1 EP with Ln 3+ mixed with PMMA (5 wt %) irradiated under UV light: (a) Eu 1 EP, (b) Tb 1 EP, and (c) EuTb 1 EP. Figure S33. Emission spectra of (a) Eu 1 EP, (b) Tb 1 EP, (c) EuTb 1 EP (λ ex = 340 nm) in PMMA films. Because the crown ether ring could form stoichiometric complexes with some metal ions, the existence of crown ether ring in this system can effectively prevent the influence of alkali and alkaline earth metal ions on the luminescence of Ln 1 EP. According to the literature procedure, 6 the logk values for the interaction of alkali and alkaline earth metal ions with dibenzo-24-crown-8 (DB24C8) are logk = 2.25 for a +, 3.45 for K +, 3.86 for Rb +, 3.85 for Cs +, and 4.04 for Ba 2+, respectively. Therein, S26

27 DB24C8 shows the highest binding ability for Ba 2+, the similar binding ability for K +, Rb +, Cs +, and the lowest binding ability for a +. The control experiment using a reference compound 4'-(p-tolyl)-2,2':6',2''-terpyridine (10) lacking the DB24C8 moiety was performed. As shown in Figure S34, the fluorescence intensity of Eu 10 complex at 617 nm was quenched greatly when the alkali and alkaline earth metal ions were added. However, the fluorescence intensity of Eu 1 EP at 617 nm increased firstly after adding the alkali and alkaline earth metal ions, and then decreased while more metal ions were added. The results suggest that the existence of crown ether ring in this system can bind with the alkali and alkaline earth metal ions, which may lead to the structure immobilization of the supramolecular assembly, accompanied by an increase of the rigidity of the assembly, which jointly cause an increase of the fluorescence intensity of Eu 1 EP. Furthermore, the addition of more alkali and alkaline earth metal ions will also quench the fluorescence of Eu 1 EP. This results convincingly demonstrated that the existence of crown ether ring in this system can effectively block out the influence of alkali and alkaline earth metal ions on luminescence of Ln 1 EP. Figure S34. Emission spectra of the Eu 10 and Eu 1 EP (0.01 mm) and (upper inset) emission intensity changes at 619 nm after adding metal ions in 1:1 CH 3 C/CHCl 3. (a) Eu 10 + a +, (b) Eu 10 + K +, (c) Eu 10 + Ba 2+, (d) Eu 1 EP + a +, (e) Eu 1 EP + K +, and (f) Eu 1 EP + Ba 2+. S27

28 We monitored the stability of 1 EP by 1 H MR spectra and HRMS. As shown in Figure S35b, the standing of a solution of 1 EP at 25 C for 3 days afforded the reconversion of 50% parent species. In addition, the HRMS result suggested that the main species was still EPs after standing at 25 C for 3 days (Figure S36). These results indicated that the reconversion of 1 EP was relatively slow. Figure S35. 1 H MR spectra monitoring the stability of 1 EP ([1 EP] = 1 mm): (a) 1 EP, (b) after 3 d standing at 25 C, and (c) the structural transformation of 1 EP by heating. Figure S36. MALDI-TF mass spectrum of 1 EP after 3 d standing at 25 C. S28

29 References: 1. Wu, D.; Shao, T.; Men, J.; Chen, X.; Gao, G. Dalton Trans. 2014, 43, Han, Y.; Guo, J. -B.; Chen, C. -F. Chinese. J. Chem. 2014, 32, Liu, X.; Xu, J.; Lv, Y.; Wu, W.; Liu, W.; Tang, Y. Dalton Trans. 2013, 42, Samanta. R. C.; Yamamoto. H. Chem. Eur. J. 2015, 21, Kaur, I.; Jia, W.; Kopreski, R. P.; Selvarasah; Dokmeci, M. R.; Pramanik, C.; McGruer,. E.; Miller, G. P. J. Am. Chem. Soc. 2008, 130, (a) Izatt, R. M.; Clark, G. A.; Lamb, J. D.; King, J. E.; Christensen, J. J. Thermochim. Acta 1986, 97, (b) Takeda, Y. Bull. Chem. Soc. Jpn. 1979, 52, S29