Supporting Information for. Diffusion-Controlled Luminescence Quenching in Metal-Organic Frameworks. Cheng Wang and Wenbin Lin*

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1 Supporting Information for Diffusion-Controlled Luminescence Quenching in Metal-Organic Frameworks Cheng Wang and Wenbin Lin* Department of Chemistry, CB#3290, University of North Carolina, Chapel Hill, NC 27599, TABLE OF CONENTS 1. General Experimental 2. Procedures for ligand synthesis 3. Synthesis and characterization of 1 4. Single Crystal X-ray structure determination 5. Procedures for N 2 adsorption measurements 6. Procedures for quenching measurement 7. Quencher release experiment 8. Procedures and raw data for GC analysis 9. PXRD patterns of 1 after being soaked in amine solutions 10. Derivation of diffusivity equations and related approximations 11. Fitting of the experimental data 12. Stern-Volmer plot of amines in homogeneous system 13. Geometry optimization of DIPEA and 4-MeOPhNPh 2 1. General Experimental All starting materials were purchased from Aldrich and Fisher, unless otherwise noted. 1 H-NMR spectra were recorded on a Bruker NMR 400 DRX Spectrometer at 400 MHz and referenced to the proton resonance resulting from incomplete deuteration of deuterated chloroform (δ 7.26). Single Crystal and Powder X-ray diffraction analyses were carried out on a Bruker SMART APEX II Diffractometer system S1

2 equipped with Cu-target X-ray tube and operated at 1600 watts. For single crystal diffraction, the frames were integrated with the Bruker SAINT build in APEX II software package using a narrow-frame integration algorithm, which also corrects for the Lorentz and polarization effects. Absorption corrections were applied using SADABS. The PXRD patterns were processed with the APEX II package using PILOT plug-in. UV-Vis absorption spectra were obtained using a Shimadzu UV-2401 PC UV-Vis Spectrophotometer. Thermogravimetric analysis (TGA) was performed using a Shimadzu TGA-50 equipped with a platinum pan, and all samples were heated at a rate of 5 C per minute under air. Nitrogen adsorption experiments were performed with a Quantachrome Autosorb-1C. Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) was performed on a Varian 820-MS machine. Quenching experiments were performed using a Shimadzu RF-5301 PC Spectrofluorophotometer. GC analysis was performed on a Shimadzu GC-2010 equipped with FID detector. Supelco β DEX 120 column was used for all the analyses. 2. Procedures for ligand synthesis. Synthesis of [bis(2,2 -bipyridine,n 1,N 1 )( 5,5 -dicarboxy -2,2 -bipyridine-) Ruthenium(II)] dichloride (H 2 L) H 2 L was synthesized by following the published procedure. [1] The compound cis-[ru(bpy) 2 Cl 2 ] (160mg, 0.33 mmol) was mixed with 2,2 -bipyridine 5,5 -dicarboxylated acid (101mg, 0.42 mmol) in 20 ml of EtOH/H 2 O, refluxed for 12 hours under Ar protection and then concentrated. The solid was recrystallized from a MeOH/diethyl ether mixture. 1 H NMR (DMSO): 8.99(d, 2H), 8.89(m, 4H), 8.53(d, 2H), 8.20(m, 4H), 7.99(s, 2H), 7.84(d, 2H), 7.78(d, 2H), 7.59(t, 2H), 7.49(t, 2H). 3. Synthesis and characterization of 1 Mixtures of H 2 L and H 2 bpdc (4,4 -biphenyldicarboxylic acid) were reacted with Zn(NO 3 ) 2 6H 2 O in DMF (N,N -dimethylformamide) under solvothermal conditions. The molar ratio of Zn(NO 3 ) 2 : H 2 L: S2

3 H 2 bpdc : DMF was 17:1: 33 : The resulting mixtures were placed in an oven at 100 o C for 12 hours. Yellow-red crystals with thin plate or feather-like shapes were obtained after filtration. The framework content of Ru-complex L in 1 was determined by both quantitative UV-Vis and ICP-MS. The UV-Vis analysis was done by dissolving a known amount of 1 in 3 ml basic water/ethanol mixture and taking quantitative UV-Vis measurements of the solution at nm. The L contents per mass could be read from the standardized curve, and the molar doping levels [mol L/(mol bpdc+ mol L)] were then calculated to be (21.2±1.0) %. In the ICP-MS measurement, the amounts of Zn and Ru in 1 were determined, and the doping level, [mol of L / (mol of bpdc+ mol of L)], was calculated from the Zn/Ru ratio to be 19.6%. Solvent contents of 1 were established by a combination of gravimetric analysis (TGA) and 1 H NMR. The complete formula of 1 was established to be [Zn 2 (BPDC) 2 L 0.5 (DMF) 9 (H 2 O) 9 ] (Solvent content calculated from proposed formula: DMF 37.6%, H 2 O 9.3% ; determined by 1 H NMR/TGA: DMF, 37.7%, H 2 O 9.3% ) Figure S HNMR spectroscopic determination of solvent content in [Zn 2 (BPDC) 2 L 0.5 ] (DMF) 9 (H 2 O) 9 (1). Mesitylene was added as an internal standard. S3

4 Figure S3.2. Thermogravimetric analysis (TGA) curve for [Zn 2 (BPDC) 2 L 0.5 ] (DMF) 9 (H 2 O) 9 (1). The sample was heated to 600 ºC at a heating rate of 5 ºC/min. 4. X-ray Structure Determination The crystallographic measurement was made on a Bruker SMART Apex II CCD-based X-ray diffractometer system operated at 1600 watts (Cu-target X-ray tube). The crystals were mounted inside a capillary tube (0.5 mm ID) with small amount of mother liquid to prevent solvent loss from the crystal frameworks. The frames were integrated with the Bruker SAINT build in APEX II software package using a narrow-frame integration algorithm, which also corrects for the Lorentz and polarization effects. Absorption corrections were applied using SADABS. Structures were solved by direct methods and refined to convergence by least squares method on F2 using the SHELXTL software suite [3]. SQUEEZE subroutine of the PLATON software suite [4] was applied to remove the scattering from the highly disordered guest molecules. The resulting new HKL4 files were used to further refine the structures. Due to the relatively weak diffraction and low resolution (>1.5 Å), which is not uncommon for this kind of framework with very large solvent accessible void space, restraints (SIMU and DELU) on displacement parameters, and DFIX for bond lengths were applied, and all the phenyl rings were constrained to ideal six-membered rings. Non-hydrogen atoms were refined isotropically. In the structure, there are three crystallographically distinct dicarboxylate ligand positions, among which two are in the equatorial positions with respect to the Zn 2 secondary building unit and one of them is S4

5 in the axial position. Except for one of the equatorial dicarboxylate ligand positions, which is exclusively occupied by BPDCs, the other two positions are occupied by BPDC/L mixed ligands. The L ligands in the equatorial positions can further disorder over two orientations resulting from an 180 o rotation along the C-C bond between the carboxylate groups and the aromatic rings. The single crystal structure was refined against the X-ray data by fixing the overall L / BPDC ratio to be 1/2 in the mixed ligand positions, based on the results from spectroscopic analysis (UV-Vis and ICP-MS). The distribution of L ligand over the two possible positions was modeled as occupancy disorder, refined by introducing a second FVAR parameter. Table S1. Crystal data and structure refinements for 1. Compound 1 Framework formula C 44 H 27 N 3 O 10 Ru 0.5 Zn 2 Formula weight Temperature (K) 296 Wavelength (Å) Crystal system Orthorhombic Space group C222 1 a = (14) b = (2) Unit cell dimensions c = (3) α = 90 β = 90 γ = 90 Volume (Å 3 ) 20751(3) Z 8 Density (calcd. g/cm 3 ) Absorption coeff. (mm -1 ) F(000) 3608 Crystal size (mm) Crystal color & shape red rectangle θ range data collection < h < 13 Limiting indices - 20 <k < < k < 30 Reflections collected 7706 Independent reflections 4641 [R int = ] Data/restraints/parameters 7706 / 171 / 294 Goodness-of-fit on F Final R indices [I>2σ(I)] a,b R1 = wr2 = R indices (all data) S5 R1 = wr2 =

6 Figure S4.1. The bnn net of 1 in ball stick model, viewed long [001] direction. Figure S4.2. The bnn net of 1 in depth view, along [001] direction. S6

7 Figure S4.3. Space-filling model of idealized 1 (without disorder) viewed long [001] direction. Figure S4.4. Space-filling model of idealized 1 (without disorder) viewed long [010] direction. S7

8 Figure S4.5. Space-filling model of idealized 1 (without disorder) viewed long [100] direction. 5. Procedures for N 2 adsorption measurements After decanting all the mother liquid, freshly prepared crystals of 1 were washed with CH 2 Cl 2 three times over a 12 hours period. The resulting crystals were washed with benzene several times and then soaked in benzene overnight before loading into a BET sample cell. About 1 ml of benzene was left in the sample cell, and the sample cell was then frozen at 0 o C. After three freeze-thaw cycles, the sample cell was placed in an ice/h 2 O bath and evacuated under a dynamic vacuum for 24 h. The ice/h 2 O bath was removed and the sample was kept under vacuum at room temperature for another 12 h, and then heated under vacuum at 60 o C for 10 h. The resulting freeze-dried 1 was used to perform gas uptake measurements. The sample after BET measurement lost most of the crystallinity, presumably due to the framework distortion upon solvent removal, a phenomenon commonly observed for MOFs with large open channels. [5] S8

9 Figure S5.1. Powder X-ray diffraction patterns of 1. PXRD pattern of the as-synthesized sample (red), simulated from single-crystal structure of 1 (black), and sample after N 2 adsorption measurement (blue). Figure S5.2. N 2 adsorption isotherms (77K) of 1. S9

10 Figure S5.3. N 2 adsorption BET plot for 1. Figure S5.4. HK poresize distribution for Procedures for quenching measurement To perform the luminescence quenching study, the as-synthesized single crystals of 1 were washed with fresh DMF for several times before use. One piece of plate-like single crystal was then glued to the bottom of a quartz fluorescent cuvette for measurement, with its face perpendicular to the bottom of the cuvette. S10

11 The crystal in the cuvette was then washed by fresh CH 2 Cl 2, fresh cyclohexane and degassed cyclohexane several times subsequently in 36 hours to exchange out the original DMF/H 2 O solvent molecules and oxygen molecules inside the MOF channels. The cuvette was then filled with 2.5 ml of degassed cyclohexane and sealed with septum under N 2. In the emission measurement, the cuvette was placed on a SHIMAZU RF-5301 PC spectrofluorophotometer with the face of the plate-like crystal set to be perpendicular to the incoming light. The height of the cuvette was carefully adjusted to immerse the whole crystal inside the light flux. The position of the cuvette was fastened before measurement. The 1 crystal was excited at a wavelength of 452 nm, and the emission spectra were recorded with a 543 nm low-pass filter in front of the detector to filter the scattering light. The quenching experiment was done by recording the intensity of the emission at the wavelength of 627 nm at different time points after adding a pre-calculated amount of amine quenchers. The TEA and 4-MeOPhNPh 2 amine quenchers were used as obtained without purification, while TPA, TBA and DIPEA were distilled before use to remove fluorescent impurities. The amines or solutions of amines were fully degassed before being added to the sealed cuvette under N 2 protection. Excitation light was blocked from impinging the crystal during the intervals between different measurements to avoid photodecomposition of the amine and other irreversible photochemical processes. A typical single measurement took about 2 to 3 seconds, during which time, the crystal and quenchers were exposed to light. The average value of the emission signal was recorded, and the random experimental error was estimated from the signal fluctuations within the 2 to 3 seconds for every single point. The final result was reported as normalized emission intensity. The random experimental error of u(t) for each point was estimated using the relationship. Spectra of the crystal were taken before and after the quenching study to make sure no substantial spectra change was present. S11

12 Figure S6.1. Time-dependent normalized emission intensity plots at the wavelength of 627 nm for 1 luminescence quenching by TEA. Results of three different runs are shown. The crystals were excited at a wavelength of 452 nm. Thickness of the crystal used in this study: run 1, 15 µm; run 2, 15 µm; run 3, 15 µm. Figure S6.2. Time-dependent normalized emission intensity plots at the wavelength of 627 nm for 1 luminescence quenching by TPA. Results of four different runs are shown. The crystals were excited at a wavelength of 452 nm. Thickness of the crystal used in this study: run 1, 15 µm; run 2, 15 µm; run 3, 20 µm; run 4, 20 µm. S12

13 Figure S6.3. Time-dependent normalized emission intensity plots at the wavelength of 627 nm for 1 luminescence quenching by TBA. Results of two different runs are shown. The crystals were excited at a wavelength of 452 nm. Thickness of the crystal used in this study: run1, 20 µm; run 2, 15 µm. Figure S6.4. Time-dependent normalized emission intensity plots at the wavelength of 627 nm for 1 luminescence quenching by DIPEA. Results of two different runs are shown. The crystals were excited at a wavelength of 452 nm. Thickness of the crystal used in this study: run 1, 10 µm; run 2, 15 µm. S13

14 Figure S6.5. Time-dependent normalized emission intensity plots at the wavelength of 627 nm for 1 luminescence quenching by 4-MeOPhNPh 2. Results of two different runs are shown. The crystals were excited at a wavelength of 452 nm. Thickness of the crystal used in this study: run 1, 15 µm; run 2, 15 µm. Figure S6.6. photos of the crystal affixed on the bottom of the cuvette. S14

15 Figure S6.7. Emission spectra for 1 before (black) and after the quenching experiments with TEA (red), TPA (blue), TBA (green), DIPEA (purple) and 4-MeOPhNPh 2 (yellow). The crystals were excited at a wavelength of 452 nm. The spectra were normalized and were shifted in the vertical direction. 7. Plots for quencher release experiment Figure S7.1. Quencher release experiment for 1 after being soaked in solutions of TPA (blue), DIPEA (green), 4-MeOPhNPh 2 (red) and as synthesized (black). The crystals were excited at a wavelength of 452 nm, and the emission signal is detected at the wavelength of 627 nm. S15

16 *due to the experimental difficulty of quickly changing solvents in the cuvette under N 2 protection without moving the cuvette cell, the quencher release experiment cannot be considered as quantitatively significant. However, the different behaviors among different amines strongly support the conclusion that TPA and 4-MeOPhNPh 2 can enter the MOF channels, while DIPEA cannot. 8. Procedures and raw data for GC analysis After soaking the MOFs in cyclohexane solutions of TPA, TBA, DIPEA and 4-MeOPhNPh 2 overnight, the MOFs were quickly washed with fresh cyclohexane three times to remove amine molecules adsorbed on the external surfaces of the crystals. The amine-treated MOFs were then digested with aqueous solutions of disodium ethylenediaminetetraacetic acid (Na 2 EDTA) and NaOH, followed by extraction of amines with CH 2 Cl 2. The amount of amine extracted was then quantified by GC, and the amount of MOFs used was obtained from ICP-MS measurement of the digesting aqueous solutions. The amount of TEA loaded in MOF channels were not quantified because of the ease for TEA to come out of the channel when washing away the molecules on the crystal surfaces, which lead to a much smaller detected number than expected. In the GC measurement, undecane was added as an internal standard. Standard solutions of TPA, TBA and DIPEA were prepared by adding 10µL of the amines to 1 ml CH 2 Cl 2. Standard solution of 4-MePhONPh 2 was made by dissolving 1.70 mg 4-MePhONPh 2 in 1mL CH 2 Cl 2. 10µL undecane was then added to each of the standard solutions. The MOF extractions were all diluted to 1mL. Then 5 µl of a stock solution of 10µL undecane /1mL CH 2 Cl 2 were added to each of the extractions. Standard sample and MOF extractions for the same amine were run on GC machine under exactly the same condition. The amount of amine in the extraction can then be calculated by comparing with the standard run: S16

17 Figure S8.1. GC data of TPA standard (upper) and TPA treated MOF extraction (lower). (Supelco β-dex 30 m 0.25 mm x 0.25 μm; injector: 240 C; Column: 120 C; Detector: 250 C; carrier gas: He (0.57 ml/min)). Amount of TPA extracted : 166 nmol. S17

18 Figure S8.2. GC data of TBA standard (upper) and TBA treated MOF extraction (lower). (Supelco β-dex 30 m 0.25 mm x 0.25 μm; injector: 240 C; Column: 140 C; Detector: 250 C; carrier gas: He (0.57 ml/min)) Amount of TBA extracted: 268 nmol. S18

19 Figure S8.3. GC data of DIPEA standard (upper) and DIPEA treated MOF extraction (lower). (Supelco β-dex 30 m 0.25 mm x 0.25 μm; injector: 240 C; Column: 120 C; Detector: 250 C; carrier gas: He (0.57 ml/min)). Amount of DIPEA extracted: 0 S19

20 Figure S8.4. GC data of 4-MeOPhNPh 2 standard (upper) and 4-MeOPhNPh 2 treated MOF extraction (lower). (Supelco β-dex 30 m 0.25 mm x 0.25 μm; injector: 240 C; Column: 140 C to 200 C; Detector: 250 C; carrier gas: He (1.5 ml/min)). Amount of 4-MeOPhNPh 2 extracted: 47 nmol. S20

21 Table S.2. Determination of the amount of amine in MOF channels Amine Symbol Amine Concentration in solution (M) Amount of amine detected by GC (nmol) Amount of Zn detected by ICP-MS (nmol) Number of absorbed amine molecules per unit-cell Effective concentration of amine inside MOF channels (M) TPA TBA DIPEA MeOPhNPh PXRD patterns of 1 after being soaked in amine solutions Figure S9.1. PXRD patters of 1 crystals as synthesized (green), and after being soaked in pure cyclohexane (red), in solutions of TEA (blue), TPA (green), TBA (purple), DIPEA (yellow), 4-MeOPhNPh 2 (dark blue). 10. Derivation of diffusivity equations and related approximations List of symbols used in this section S21

22 I 0 i 0 I(t) : emission of the crystal in the absence of quenchers : the excitation light density : detected emission as a function of time I( ) : equilibrium emission intensity after adding quenchers for a long time u(t) : normalized emission intensity D : diffusivity within the crystals, c 0 : the concentration of a diffusant in the bulk solution surrounding the crystal L : the thickness of the crystal β : activity coefficient correction for quencher concentration within the MOF channels : quantum yield of MOF in the absence of quencher : absorption parameter of MOF is the extinction coefficient, while n is the effective dye concentration in MOFs. : fraction of surface emission contribution to total emission of the crystal : tilting angle of the crystal with respect to the direction of excitation light γ : crystal geometry and position coefficient : Stern Volmer constant for the particular quencher in cyclohexane 10.1 Diffusion model We plan to construct a working model for TEA, TPA and TBA diffusion inside 1 in the frame of Fickian diffusion. The diffusion process for 4-MeOPhNPh 2 is more complicated than simple Fickian diffusion, and is not included in this analysis. For molecules to diffuse into plate-like MOF crystals, the problem is simplified to one-dimensional diffusion by ignoring contributions from the other two longer dimensions. As shown in scheme S.1, during the process of diffusion, the local concentration of a diffusant within the MOF crystal at a given time t is different for different position x in the crystal. We can then represent the diffusant concentration as a function of both time and position c(x,t). This one dimensional diffusion problem can then be described by Fick s Second Law of diffusion, combined with the boundary conditions and initial conditions as follows. c o 0 Scheme S.1 Crystal L x,, (eq.1) 0,, (eq.2), (eq.3) D is the diffusivity within the crystals, c 0 is the concentration of a diffusant in the bulk solution surrounding the crystal L is the thickness of the crystal A solution to this differential equation is S22

23 / sin, 1 (eq.4) This is the standard mathematical solution of the diffusion equation in a plane sheet with uniform initial distribution. [6] It is easy to see that,, which simply means that after waiting for infinite amount of time, the diffusant concentration all through the MOF crystal will be equal to the concentration in the bulk solution. In the above equation, we totally ignored the fact that interactions between the particular diffusant molecules and MOF channels may cause the equilibrium to favor or disfavor molecules entering MOFs, leading to different effective equilibrium diffusant concentration within MOFs from that in the outside solution. As a first order correction to this error, we can introduce a diffusant dependent parameter β to represent the correction to equilibrium diffusant concentration in MOFs. (This correction is equivalent to using activity to replace concentration. The β parameter corresponds to activity coefficient.) We hereby reformulate c(x,t) as / sin, 1 (eq.5) 10.2 Model for the phosphorescence from a single crystal The first thing to notice is that the light is not evenly distributed through the whole crystal. The light intensity is attenuated when penetrating through the MOF crystal according to Lambert-Beer s Law. The simplest situation is that the incoming light is perpedicular to the surface of the crystal like in scheme S.2. Sectioning the plate-like crystal to several slices parallel to the plate surface and considering the emission from each slice with the width of dx, the emission from this slice in the absence of quencher Scheme S.2 should be proportional to the local light intensity. di (eq.6) i 0 is the incoming light density hv is the quantum yield of MOF in the absence of quencher The term accounts for Larmbert-Beer s Law is the extinction coefficient, while n is the effective dye concentration in MOFs. So the emission intensity without quenchers is: (eq.7) When quenchers inside the MOFs are considered, emission from each MOF slice is dynamically quenched according to Stern-Volmer equation 1, (eq.8) is Stern-Volmer constant for the particular quencher. 0 dx Crystal L x So,, (eq.9) S23

24 However, the crystal cannot be placed precisely in the perpendicular position to the incoming light, as shown in Scheme S3. To correct this effect, in the above expressions (eq.7 to eq.10) should be replaced by /. Another factor to take into account is that not all the emission light can be detected by the detector. The amount of detectable emission is sensitive to the exact position and geometry of the specific single crystal. Thus, a crystal dependent common coefficient γ should be formulated into the expressions. In addition, quenching of dye molecules near the surface of MOFs can account for a significant amount of detected emission, when considering the fact that the slices near the surface of the MOF crystal contribute (eq.10) more to the detected emission I 0 because incoming light will attenuate while penetrating deeper into the bulk crystal. Assuming that surface quenching occurs immediately after adding the quencher, and the surface emission accounts for fraction of total emission of the crystal. The intensities can then be expressed as the sum of two terms from the surface and the bulk crystals. With these considerations, the expressions for emission intensities are modified to: h 0 Scheme S.3 detector θ Crystal x x/cos θ L Light source 1 / (eq.11) /, (eq.12) 1 / (eq.13) Because of the possibility of slightly moving the cell when adding a quencher and unpredictable issues related to surface quenching, it is much more reliable to use intensity at infinite time ( ) to normalize the data than using intensity ratio of /. The I 0 value is still useful to evaluate the magnitude of the Stern-Volmer constant of the specific quencher in cyclohexane,times β, both of which are basically unknown. ~ 1 (eq.14) As shown below, from the experimental data, the value of is less than 0.1 for TEA, TPA and TBA diffusion. This piece of information is very useful to simplify the above equations. Define the observable as As a first-order approximation, /, /, (eq.15) (as / 0 S24

25 / / / / 1 / / sin / sin / / If we just use the first term in the summation series: / / (eq.16) (eq.17) / Here A is a term independent of time t; L is the thickness of the crystal which can be measured for each crystal. Then diffusivity can be obtained by a linear fitting of the plot of ln[u(t)] vs. t. However, the validity of this truncation is subject to further evaluation. The complete expression (eq.16) can be reformulated as 1 / (eq.18) / (eq.19) Only when 1 can we use eq.17 to replace eq.18. We know M(t) will be significant when t is small, but will decay very quickly when t gets large. We can thus minimize this truncation error by cutting off data points from the first 200s. To quantitatively evaluate the effect of this truncation, we need to know , which we measured experimentally on the homogeneous compound. If we let 1, we can estimate the value of m by S25 The fitting was performed in the time scale of t > 100 to 200 s, so we can use t lower limit to calculate the upper limit of this truncation error. As shown in Table S.1, the resultant upper limit of M(t) value for TEA, TPA and TBA diffusions are all less than 15%, which are quite acceptable when considering the presence of experimental errors that are much larger than this amount. To precisely evaluate the effect of residue M(t) on the diffusivity calculation, the M(t) contribution to the diffusivity can be calculated by ln 1. This is a monotone decreasing function and gets its maximum at the beginning point. %500 at a selected typical time t = 500 s is used as an estimation of the percent error introduced by the above mathematical truncation.

26 Table S.3. Fitting results of diffusion controlled quenching Quencher TEA TPA TBA run Diffusivity M(t) upper percent error ( m 2 t lower limit /s /s) limit %E(500) ± <0.01% ± <0.01% ± <0.01% ± % ± % ± % ± % ± % ± % 11. Fitting of the experimental data A plot of ln. was fitted linearly for different runs of TEA, TPA and TBA diffusions. The error bars in these plots were estimated using the relationship of ln ln. The error from crystal thickness measurement was not considered in these error bars. The linear fitting was performed in Origin 7.5 program with the error weighting strategy selected as instrumental. The estimated error on diffusivity of each fitting was directly copied from the Origin program. The average value of diffusivity based on multiple runs was calculated. When the estimated error within each fitting was smaller than the differences among different runs, the overall estimated error for reported diffusivity was derived from the differences among multiple runs. When the differences among different runs were small, the fitting error was also considered in the final reported value. The intercepts of these fittings, related to the pre-exponential A term in eq. 17, depend on specific crystal geometry, position (from δ term) and placing angle θ, and are thus different from run to run. S26

27 Figure S11.1. Linear fitting of different runs of TEA quenching data. Data range used for the fitting 100 s < t < 1000 s. D = (1.1±0.2) m 2 /s. Thickness of the crystal used in this study: run 1, 15 µm; run 2, 15 µm; run 3, 15 µm. Figure S11.2. Linear fitting of different runs of TPA quenching data. Data range used for the fitting 200 s < t < 2000 s. D = (4.8±1.2) m 2 /s. Thickness of the crystal used in this study: run 1, 15 µm; run 2, 15 µm; run 3, 20 µm; run 4, 20 µm. S27

28 Figure S11.3. Linear fitting of different runs of TBA quenching data. Data range used for the fitting 200 s < t < 2000 s. D = (4.0±0.4) m 2 /s. Thickness of the crystal used in this study: run 1, 20 µm; run 2, 15 µm. 12. Stern-Volmer plot of amines in homogeneous systems 1mg of H 2 L was dissolved in a mixture of 2.5 ml acetonitrile, 0.5 ml DMF and 10 µl 6M NaOH aqueous solutions. The solutions were well degassed and amine quenchers were added into the system to quench the emissions. The excitation wavelength was fixed at 452 nm and Emission maximum at 605 nm was recorded in the Stern-Volmer plot. Figure S12.1. Stern-Volmer plot of TEA quenching in the homogeneous system S28

29 Figure S12.2. Stern-Volmer plot of TPA quenching in the homogeneous system Figure S12.3. Stern-Volmer plot of TBA quenching in the homogeneous system S29

30 Figure S12.4. Stern-Volmer plot of DIPEA quenching in the homogeneous system Figure S12.5. Stern-Volmer plot of 4-MeOPhNPh 2 quenching in the homogeneous system 13. Geometry optimization of DIPEA and 4-MeOPhNPh 2 S30

31 Molecule models of DIPEA and 4-MeOPhNPh 2 were built in Materials Studio v 5.0 [2], and pre-optimized by force field based method using the Forcite module. Geometry optimizations were performed on Gaussian 03 software, [7] using DFT method. B3LYP functional was used in the calculation. The basis sets were set to be 6-31G* for C and H, and G* for O and N. Solvation in cyclohexane was also considered in the calculation using CPCM model. A comparison of the optimized structures of DIPEA and 4-MeOPhNPh 2 are shown in Figure S.13.1 in space-filling model Å 8.0 Å 4 MeOPhNPh 2 DIPEA Figure S 13.1 Comparison between the sizes of DIPEA and 4-MeOPhNPh 2 as computed by geometry optimization using DFT. References. 1. Xie, P. H.; Hou, Y. J.; Zhang, B. W.; Cao, Y.; Wu, F.; Tian, W. J.; Shen, J. C. J. Chem. Soc., Dalton Trans., 1999, Materials Studio v 5.0. Accelrys Software Inc., San Diego, CA 92121, USA 3. Bruker AXS SHELXTL version Structure Determination Package. Bruker AXS Madison, WI, USA. 4. A. L. Spek, (2008) PLATON, A Multipurpose Crystallographic Tool, Utrecht University, Utrecht, The Netherlands. 5. (a) Serre, C.; Millange, F.; Thouvenot, C.; Nogues, M.; Marsolier, G.; Louer, D.; Ferey, G. J. Am. Chem. Soc. 2002, 124, (b) Ghoufi, A.; Maurin, G. J. Phys. Chem. C. 2010, 114, (c) S31

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