Supporting Information for A Water-Soluble Switching on Fluorescent Chemosensor of Selectivity to Cd 2+ Weimin Liu, a Liwei Xu, a Ruilong Sheng, a Pengfei Wang,*,a Huaping Li*,b and Shikang Wu a a Laboratory of rganic ptoelectronic Functional Materials and Molecular Engineering, Technical Institute of Physics and Chemistry, the Chinese Academy of Sciences, Beijing, 100080, China; b Department of Chemistry & Biochemistry University of California, Santa Barbara, CA 93106 wangpf@mail.ipc.ac.cnhli@chem.ucsb.edu Content 1. Materials and Methods 2. Synthesis of compound 1 3. Figure S1. 4. Figure S2 5. Figure S3. 6. Figure S4. 7. Figure S5 8. Figure S6 1
1. Materials and Methods. Deleted: Cationic compounds such as NH 4 Cl 4, LiCl 4, NaCl 4, KCl 4, Mg(Cl 4 ) 2, Ca(Cl 4 ) 2, Pb(Cl 4 ) 2, Fe(Cl 4 ) 2, Cu(Cl 4 ) 2, Zn(Cl 4 ) 2, Cd(Cl 4 ) 2, Hg(Cl 4 ) 2 were purchased from Aldrich; MnS 4, CoCl 2 and NiCl 2 were from Beijing Chemical. All these cations were used as received. Fluorescein was analytical grade from Beijing Chemical and recrystallized once before use. HEPES (50 mm HEPES, 100 mm KCl buffer, ph = 7.0) was from Alfa Aesar. All other reagents are analytical grade from Beijing Chemical. UV-vis absorption and fluorescence spectra were recorded in Hitachi U-3010 absorption spectrometer and Hitachi F-4500 fluorescence spectrometer, respectively. NMR spectra were recorded on Bruker-400 (400 MHz). Mass spectroscopy was measured on Finnigan 4021C MS-spectrometer instrument and APEXII FT-ICR MS-spectrometer instrument, respectively. All measurements were measured in HEPES buffer solution except specific description. The stock solution of 1 was prepared in DMS (1.0 10 3 M), stored at -25 C and thawed in the dark before use. The cationic solutions were prepared in distilled water with a concentration of 1.0 10 2 M for fluorescence and UV-Vis spectra analysis. Each time a 2 ml of 1 was filled in a quartz cell of 1 cm of optical path length, and the stock solution of cations was added into the quartz cell dropwisely using a micro-syringe. The volume of cationic stock solution added was less than 100 µl to remain the concentration of 1 unchanged. All fluorescence spectra were recorded at 25 C with the excitation of 480 nm. Fluorescence quantum yields were determined by comparing the emission intensity of the sample with that of a fluorescence standard using the following equation: 2
= S R A F n A F n 2 R S S 2 S R R Formatted: Centered where A and F are the absorption and integrated fluorescence intensity respectively; n is the refractive index of the solvent; S and R represent the sample and reference, respectively. Fluorescence quantum yield used for the reference is the fluorescein in Deleted: u = r(a r F u n u 2 )/(A u F r n r 2 ) Deleted: u Deleted: r 0.1 M of NaH aqueous solution with a known quantum yield of 0.85. HK-2 cells (gifted from the center of cells, Peking Union Medical College) were Deleted: cultured in culture media (DMEM/F12 supplemented with 10% FBS, 50 unit/ml penicillin, and 50 ug/ml of streptomycin) at 37 C in a humidified incubator. HK-2 cells were seeded in a 6-well plate at a density of 104 cells per well in culture media. After 24 h, the cells were incubated with 10 µm of compound 1 in culture media for 20-30 min at 37 C. After carefully washing with PBS to remove free compound 1, compound 1 pretreated cells were then incubated with Cd(Cl 4 ) 2 in different concentrations in culture media for another 30 min at 37 C. These cells were imaged using confocal fluorescence microscopy (excitation light source: Green; lympus IX 71 S 8F-2). 3
2. Synthesis of compound 1 Compound 2. To fluorescein (2.5 g, 7.75 mmol) methanol solution (3 ml) in a 100 ml of three-neck round-bottom flask at 55 C, was carefully added 10 g of NaH solution (50%, weight percent), 2.42 ml of CHCl 3 (30 mmol), and 0.03 g of benzo-15-crown-5. The mixture solution was stirred at same temperature for 6 h. After cooling, the mixture solution was acidified with HCl (5 M) and the solid was Deleted: precipitated out. The obtained solid compound was chromatographed on a silica gel column using EtAc/DCM mixture solvent (1/10) as eluent. A light yellow solid (620 mg) was obtained in a yield of 31%. 1 H NMR (DMS-d 6, 300 MHz) (ppm): 6.60 (2H, s), 6.68-6.71 (1H, d, J = 9.0 Hz), 6.84 (1H, s), 6.93-6.96 (1H, d, J = 9.0 Hz), 7.29-7.32 (1H, d, J = 7.4 Hz), 7.72-7.78 (2H, m) 7.99-8.02 (1H, d, J = 7.5 Hz), 10.26 (1H, s), 10.62 (1H, s), 11.87 (1H, s). EI+ MS: m/z, 361. Compound 1. Compound 2 (90 mg, 0.25 mmol) and thiosemicarbazide (28 mg, 0.31 mmol) were dissolved in 50 ml of absolute ethanol, a salmon pink solution was obtained. After the mixture solution was refluxing for 4 hour, and the precipitate was filtrated, then washed with hot absolute ethanol three times. The pink solid 1 (60 mg, 0.14 mmol) was recrystallized from absolute C 2 H 5 H in a yield of 70%. 1 H NMR (DMS-d 6, 400 MHz) (ppm): 6.58-6.71 (5H, m), 7.31-7.33 (1H, d, J = 7.5 Hz), 7.71-7.52 (1H, t, J = 7.4 Hz), 7.79-7.83 (1H, t, J = 7.4 Hz), 8.01 (1H, d, J = 7.6 Hz), 8.10 (1H, s), 8.28 (1H, s), 8.95 (1H, s), 10.21 (1H, s), 10.29 (1H, s), 11.57 (1H, s). 13 C NMR (DMS-d 6, 100 MHz) (ppm): 82.6, 102.3, 106.3, 109.5, 110.1, 113.2, 113.3, 124.2, 124.9, 126.1, 129.2, 130.4, 130.5, 135.9, 140.8, 149.9, 151.3, 152.3, 158.1, 159.5, 168.8, 172.1. HRMS found (EI-H + ): m/z, 432.0660, Calcd. 433.0660. 4
3. Figure S1. 1 H NMR (top) and 13 C NMR (bottom) of compound 1 in DMS-d6. S H 2 N H NH N H Deleted: S H 2 N H NH N H Deleted: 5
4. Figure S2. Fluorescence response of 1 (5 µm) to Cd 2+ in the presence of various cations (NH + 4, Li +, Na +, K +, Mg 2+, Ca 2+, Mn 2+, Pb 2+, Fe 2+, Co 2+, Ni 2+, Cu 2+, Hg 2+, Zn 2+ ) in HEPES buffer solution (50 mm HEPES, 100 mm KCl, ph=7.0). White bars represent the fluorescence response of 1 (5 µm) upon addition of 20 equiv. of other cations. Black bars represent the fluorescence response of 1 (5 µm) to 20 equiv of Cd 2+ in the presence of 20 equiv of other cations ( ex = 480 nm). Deleted: 2 Deleted: Gray Deleted:. Deleted:. 2.5 2.0 F / F 0 1.5 1.0 0.5 NH 4 + Li + Na + K + Mg 2+ Ca 2+ Mn 2+ Pb 2+ Fe 2+ Co 2+ Ni 2+ Cu 2+ Hg 2+ Zn 2+ Cd 2+ 5. Figure S3. UV-Vis spectra of 1 (5 µm) in HEPES buffer solution before and after addition of 20 equiv of Cd 2+. Deleted:. Absorbance 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 Compound 1 Compound 1 + Cd 2+ 400 450 500 550 600 Wavelength(nm) 6
6. Figure S4. A nonlinear curve fitness based on 1:1 complex expression: F = + + + + + F0 2F0 2 C K C C K C C 1 2 2 Fmax 1 C 1 M CM 1 C M 1 1 1 4 L S L L S L L Formatted: Centered where F and F 0 are the fluorescence intensity of ligand 1 in the presence and absence of Cd 2+, C M and C L are the concentrations of Cd 2+ and ligand 1; K S is the stability constant. 2.6 2.4 2.2 2.0 F / F 0 1.8 1.6 1.4 1.2 1.0 0.8 Data: Data1_B Model: lwm1 Equation: y=1+(p1/116.78-0.5)*(1+x+100000/p2-sqrt((1+x+100000/p2)^2-4*x)) Weighting: y No weighting Chi^2/DoF = 0.00056 R^2 = 0.99797 P1 146.41027?.15464 P2 8139630.16312? 005429.31125 0.0 0.5 1.0 1.5 2.0 2.5 C M / C L 7
7. Figure S5. ESI Mass Spectroscopy of 1 + Cd 2+ complex. Deleted: 6 Deleted: 4 NH 2 S NH N Cd CH Deleted: 8
8. Figure S6. Confocal images of HK-2 cells incubated with compound 1 (10 µm) for 30 min at 37 C and then treated with (a) 0 µm, (b) 5 µm, (c) 10 µm, (d) 20 µm of Cd 2+ Deleted: 7 Deleted: 5 for 30 min 9