Bistable Polyaromatic Aminoboranes: Bright Solid State Emission and Mechanochromism

Transcription

1 Supporting Information Bistable Polyaromatic Aminoboranes: Bright Solid State Emission and Mechanochromism Neena K. Kalluvettukuzhy and Pakkirisamy Thilagar* Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore , India; S1

2 Table of Contents SI. No. Contents Page No. 1. Chemical structure and synthetic scheme of copounds 1-4 S3 2. NMR spectral characterization S4-S9 3. HRMS charcterization S10-S11 4. Optical properties S12-S19 5. Crystal structure characterization S20-S23 6. Aggregation induced emission (AIE) studies S24-S27 7. Mechanochromic properties S28-S29 8. References S29 S2

3 Chart S1. Chemical structure of aminoboranes 1, 2, 3 and 4. Scheme S1. Synthetic scheme of aminoboranes 1, 2, 3 and 4. S3

4 NMR Spectral Characterizations Figure S1. 1 H NMR spectrum of compound 1 Figure S2. 13 C NMR spectrum of compound 1 S4

5 Figure S3. 1 H NMR spectrum of compound 2 Figure S4. 13 C NMR spectrum of compound 2 S5

6 Figure S5. 1 H NMR spectrum of compound 3 Figure S6. 13 C NMR spectrum of compound 3 S6

7 Figure S7. 1 H NMR spectrum of compound 4 Figure S8. 13 C NMR spectrum of compound 4 S7

8 Figure S9. 1 H NMR spectrum of compound 3a Figure S C NMR spectrum of compound 3a S8

9 Figure S11. 1 H NMR spectrum of compound 4a Figure S C NMR spectrum of compound 4a S9

10 HRMS Characterization Figure S13. HRMS of compound 1 Figure S14. HRMS of compound 2 S10

11 Figure S15. HRMS of compound 3 Figure S16. HRMS of compound 4 S11

12 Optical Properties Figure S17. Absorption (left, inset shows the absorption spectra in the region of nm), and the normalized emission spectra of compounds 1, 2, 3 and 4 measured in THF solvent (conc. 10 M and λ ex = 350 nm). Figure S18. Simulated absorption spectra of compounds 1, 2, 3 and 4 from TD-DFT calculations. Table S1. Photophysical data of compounds 1, 2, 3 and 4 measured in THF solvent (Conc. 10 M and λ ex = 350 nm). λ abs (nm) (ε, M -1 cm -1 ) λ em (nm) ν (cm -1 ) a Φ F (103900), 300 (31300) (105000), 315 (62800) (36600), 244 (33600), (24000), 340 (48800) (181000), 250 (37100), (73600) a (Φ = Φ F (I/I R ) (A R /A) (η 2 /η 2 R ), where Φ = quantum yield, I = area under the curve of emission spectrum, A = absorbance, η = refractive index of solvent, quantum yield is calculated with reference to anthracene, Φ F = 0.27 in EtOH). S12

13 Figure S19. Absorption spectra of compounds 1 (top left), 2 (top right), 3 (bottom left) and 4 (bottom right) in different solvents (Conc. 10 M). Figure S20. Normalized emission spectra of compounds 1 (top left), 2 (top right), 3 (bottom left) and 4 (bottom right) in different solvents (Conc. 10 M, λ ex = 350 nm). S13

14 Table S2. PL data of compound 1, 2, 3 and 4 in different Solvents (Conc. 10 M and λ ex = 350 nm). Solvent λ abs (nm) (ε, M -1 cm -1 ) λ em (nm) ν (cm -1 ) a Φ F Hexane 300 (37300) DCM 302 (28000) CHCl (26100) No fluorescence observed 1 EtOAc 299 (29000) ACN 299 (29700) MeOH 300 (27800) No fluorescence observed Hexane 315 (43900) DCM 315 (38600) CHCl (45200) EtOAc 312 (44400) ACN 312 (40600) MeOH 312 (40700) Hexane 336 (31500) DCM 337 (29500) CHCl (24500) EtOAc 337 (24700) ACN 335 (29200) MeOH 336 (29900) Hexane 340 (68300) DCM 340 (61100) CHCl (62600) EtOAc 339 (57400) ACN 337 (61800) MeOH 338 (62300) a (Φ = Φ F (I/I R ) (A R /A) (η 2 /η 2 R ), where Φ = quantum yield, I = area under the curve of emission spectrum, A = absorbance, η = refractive index of solvent, quantum yield is calculated with reference to anthracene, Φ F = 0.27 in EtOH). S14

15 Figure S21. DFT optimized structures of 1 (top left), 2 (top right), 3 (bottom left) and 4 (bottom right). S15

16 Table S3. Important bond lengths, bond angles and torsion angles of 1, 2, 3 and 4 from DFToptimized ground state structures B1-N B1-C B1-C N1-C N1-C N2-C N3-C B2-C B3-C C1-B1-C N1-B1-C N1-B1-C C19-N1-C B1-N1-C B1-N1-C C1-B1-N1-C C7-B1-N1-C C1-B1-N1-C C7-B1-N1-C S16

17 Figure S22. Orientation of ground state dipole moment of compounds of 1, 2, 3 and 4. Table S4. Ground state and excited state dipole moment values of 1, 2, 3 and 4 Compound Dipole moment (Debye) No. Ground state ( g ) a Excited state ( e ) b = e - g a obtained from DFT calculations; b s = (2 2 /hca 3 0 ) f(x) + A, where Δμ is the electric dipole moment change upon electronic transition and h, c, a o, and A are the Planck s constant (h = x J s), speed of light (c = 2.99 x 10 8 m/s), Onsager radius of fluorophore and a constant. S17

18 Table S5. Summary of dominant electronic transitions of compounds 1, 2, 3 and 4 obtained from TD-DFT calculations. Compound Excited State E/eV E/nm f Dominant transitions (percent contribution) HOMO ->LUMO (96%) HOMO ->LUMO+1 (82%) HOMO ->LUMO+2 (82%) HOMO ->LUMO+3 (94%) HOMO ->LUMO+4 (84%) HOMO-1 ->LUMO (94%) HOMO ->LUMO (97%) HOMO-1 ->LUMO (58%) HOMO ->LUMO+1 (44%) HOMO-1 ->LUMO (39%) HOMO ->LUMO+3 (54%) HOMO ->LUMO+4 (44%) HOMO ->LUMO (91%) HOMO-1 ->LUMO (93%) HOMO-4 ->LUMO (72%) HOMO-5 ->LUMO (72%) HOMO-7 ->LUMO (91%) HOMO-3 ->LUMO (40%) HOMO ->LUMO (90%) HOMO ->LUMO+1 (90%) HOMO-1 ->LUMO (56%) HOMO-2 ->LUMO (58%) HOMO-5 ->LUMO (48%) S18

19 Table S6. Photophysical data of compounds 1, 2, 3 and 4 in solid state (λ ex = 350 nm for steady state luminescence measurements and 340 nano-led used for TRF measurements). λ em (nm) Φ F a τ b (ns) k r (*10 9 s -1 ) c k nr (*10 9 s -1 ) c a absolute luminescence quantum yield in solid state measured with a calibrated integrating sphere; b average excited state life time in solid state; c following equations have been used for the calculation of k r and k nr ; {ϕ F = k r /(k r +k nr )} and {τ = 1/(k r +k nr )}, 1 where ϕ F is the fluorescence quantum yield, τ is the average life time and k r and k nr are the radiative and nonradiative decay rate constants, respectievely. S19

20 Crystal Structure characterization Table S7. Crystallographic refinement data of compounds 1, 2, 3 and Empirical C 42 H 41 B 1 N 2 C 58 H 55 B 1 N 3 C 48 H 53 B 2 N C 66 H 74 B 3 N formula Formula weight Temperature(K) 293(2) 100(2) 293(2) 296(2) Wavelength (Å) Crystal system Monoclinic Triclinic Monoclinic Triclinic Space group P 21/c P -1 P 21/n P -1 a/ Å (2) (3) (3) (1) b/ Å 9.363(8) (3) (5) (1) c/ Å (3) (5) (5) (1) α/ (2) (6) β/ (1) 79.4(2) 90.7 (2) 95.0 (6) γ/ (3) (5) V/Å (6) (1) (1) (5) Crystal size (mm) 0.12 x0.09 x x 0.20 x x0.15 x x 0.20 x 0.15 Z Density (Mg m -3 ) Final R [I>2s(I)] [a], [b] R1 = , wr2 = R1 = , wr2 = R1 = , wr2 = R1 = , wr2 = R (all data) [a], [b] R1 = , wr2 = R1 = , wr2 = R1 = , wr2 = R1 = , wr2 = Collected reflns Unique reflns Theta range for 2.4 to to to to 25.0 data collection Absorption mm mm mm mm -1 coefficient Goodness-of-fit on F 2 CCDC No [a] R 1 = Σ F o F c / Σ F o. [b] wr 2 = [Σ{w(F o 2 F c2 ) 2 }/Σ{w(F o2 ) 2 }] 1/2 S20

21 Table S8. Important bond lengths, bond angles and torsion angles of 1, 2, 3 and 4 from molecular structures. (Molecular Structures of compounds 1 (top left), 2 (top right), 3 (bottom left) and 4 (bottom right) with atom nubering schems are shown at the bottom of the table) B1-N (5) 1.431(3) 1.435(2) 1.431(3) B1-C (1) 1.598(3) 1.584(2) 1.576(3) B1-C (1) 1.591(3) 1.591(2) 1.591(3) N1-C (4) 1.440(2) 1.438(2) 1.448(2) N1-C (4) 1.444(2) 1.441(2) 1.439(3) N2-C (4) 1.424(2) - - N3-C (2) - - B2-C (3) 1.573(3) B3-C (4) C1-B1-C (3) 124.6(2) 124.6(1) 123.0(2) N1-B1-C (3) 118.0(2) 120.1(1) 118.7(2) N1-B1-C (3) 117.3(2) 115.4(1) 118.3(2) C19-N1-C (3) 114.6(1) 115.4(1) 114.8(2) B1-N1-C (3) 122.6(2) 120.1(1) 121.9(2) B1-N1-C (3) 122.5(2) 124.5(1) 123.3(2) C1-B1-N1-C19-6.9(5) -11.7(3) (1) -12.8(3) C7-B1-N1-C (5) -6.5(3) (1) -12.7(3) C1-B1-N1-C (3) 175.3(2) 21.6(2) 167.2(2) C7-B1-N1-C (3) 166.5(2) 18.6(2) 167.3(3) S21

22 S22

23 Figure S23. Intermolecular interaction diagrams of compound 1 (top), 2 (top middle), 3 (bottom middle) and 4 (bottom). S23

24 Aggregation Induced Emission Studies Figure S24. PL spectra of 3 (left) and 4(right) in THF/water mixtures with different water fraction (f w (V%), (Conc. 100 M, λ ex = 350 nm and inset shows the PL spectra at lower water fractions, f w (V%) is 0 to 50 for 4) and the corresponding images of compounds in THF with increasing water fraction taken under UV light illumination (λ ex = 365 nm). Figure S25. Relative PL intensities of 1(top left), 2 (top right), 3 (bottom left) and 4 (bottom right) in THF/water mixtures with different water fraction (f w (V%), (Conc. 100 M, λ ex = 350 nm). S24

25 Figure S26. Absorption spectra of compounds 1(top left), 2(top right), 3 (bottom left) and 4 (bottom right) in THF and 1:9 THF-H 2 O mixture (Conc. 10 M). Figure S27. Transmission electron microscopy (TEM) images of molecular aggregates of 1 (top left), 2 (top right), 3 (bottom left) and 4 (bottom right) and inset shows the corresponding SAED pattern. S25

26 Figure S28. Time-resolved fluorescence decay profile of compounds 1 (top left), 2 (top right), 3 (bottom left) and 4 (bottom right) in THF with different water fractions (f w (V%)), (Conc. 100 M, λ ex = 340 nm). Table S9. TRF data of compounds 1, 2, 3 and 4 (Conc M, λ ex = 340 nano-led) in THF with different water fractions, f w (V%). f w (V%) τ 1 (ns) A1 τ 2 (ns) A2 τ (ns) a a average excited state life time at solid state S26

27 Figure S29. PL spectra of 1 (left) 2 (middle) and 3 (right) respectively in MeOH/Glycerol mixtures with different glycerol fraction, f G (V%) (Conc. 100 M, λ ex = 350 nm, and inset shows the PL spectra at lower glycerol fractions, note: Compound 4 is insoluble in MeOH, so viscosity measurements haven t been performed). Figure S30. PXRD traces of molecular aggregates of 2 formed with different water fractions (f w (V%) = 60 and 90). S27

28 Mechanochromic Properties Table S10. Mechnochromic luminescence data of compounds 1and 2 (λ ex = 350 nm for steady state luminescence measurements and 340 nano-led for TRF measurements). Compound λ em (nm) Φ F a τ b (ns) k r (*10 9 s -1 ) c k nr (*10 9 s -1 ) c 1 Pristine Crystal Ground Pristine Ground a absolute luminescence quantum yield at solid state measured with a calibrated integrating sphere; b average excited state life time at solid state; c following equations have been used for the calculation of k r and k nr ; { ϕ F = k r /(k r +k nr )} and {τ = 1/(k r +k nr )}, 1 where ϕ F is the fluorescence quantum yield, τ is the average life time and k r and k nr are the radiative non-radiative decay rate constants, respectievely. Figure S31. Reversible fluorescence responses of 1 (left) and 2 (right) over ten successive cycles of grinding and annealing/solvent vapor fuming processes. (λ ex = 350nm). S28

29 FigureS32. Luminescence spectra of compound 2 with differnet applied pressures (λ ex = 350 nm). References 1. Kupcewicz, B.; Małecka, M. Cryst. Growth Des. 2015, 15, S29