Spin Orbit Charge Transfer Intersystem Crossing in the. Perylenemonoimide Phenothiazine Compact. Electron Donor Acceptor Dyads

Transcription

1 Electronic upplementary Material (EI) for Chemical Communications. This journal is The Royal ociety of Chemistry 2018 Electronic upplementary Information for: pin rbit Charge Transfer Intersystem Crossing in the Perylenemonoimide Phenothiazine Compact Electron Donor Acceptor Dyads Yingjie Zhao, a Ruomeng Duan, b Jianzhang Zhao* a and Chen Li* b a tate Key Laboratory of Fine Chemicals, chool of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling-Gong Road, Dalian , P. R. China zhaojzh@dlut.edu.cn b chool of Environment and Civil Engineering, Dongguan University of Technology, o.1, Daxue Rd., ongshan Lake, Dongguan, Guangdong Province, P. R. China lichen@mpip-mainz.mpg.de 1

2 Contents 1. General Information yntheses of the Compounds Molecular tructure Characterization Data UV Vis Absorption pectra Fluorescence pectra inglet xygen Quantum Yield anosecond Time-resolved Transient Absorption pectra Delayed Fluorescence pectra Discussion on the Decay of the Charge eparated tates (C) of the Dyads DFT ptimized Ground tate Geometry Fluorescence Excitation pectra x,y,z Coordinates of the ptimized Ground tate Geometry of the Compounds References

3 1. General Information All the chemicals used in synthesis are analytically pure and were used as received. olvents were dried and distilled prior to use. 1 H and 13 C MR spectra were recorded on the Bruker Avance spectrometers (400 MHz or 500 MHz). 1 H and 13 C chemical shifts are reported in parts per million (ppm) relative to TM, with the residual solvent peak used as an internal reference. The mass spectra were measured by HRM (MALDI-TF) and HRM (EI). The fluorescence spectra of compounds were recorded on a RF-5301PC spectrofluorometer (himadzu, Japan) at room temperature. In the comparison of the fluorescence intensity of different solutions, optically matched solution of compounds were sued, i.e. the absorbance of compounds at the excitation wavelength were adjusted to be the same, in order to eliminate the effect of fluorescence intensity caused by the difference in the absorbance of compounds. The fluorescence quantum yields were measured with the relative method, i.e. BDP-1 was used as standard (molecular structure was shown in cheme 1. F = 4.4% in toluene). In some cases BDP was used as standard for the fluorescence quantum yield measurement ( F = 72% in THF). Luminescence lifetimes were measured on an B920 luminescence lifetime instrument (Edinburgh Instruments, U.K.), equipped with EPL picosecond pulsed laser and TCPC detection modules. The radiative rate constant (kr) and non-radiative rate constant (knr) of compounds were calculated using the following equation 1 and 2, based on the fluorescence of the charge transfer state (CT emission): k F r (1) k 1 (2) nr - F In the above equations, F is the fluorescence quantum yield and is the fluorescence lifetime of the compound. inglet oxygen quantum yields ( ) of compounds were measured with 1,3- diphenylisobenzofuran (DPBF) as singlet oxygen scavenger. By following the absorption (λmax = 414 nm) of DPBF, the 1 2 production was monitored. For calculation of singlet oxygen quantum yield (Φ ), the following equation 3 was used: Astd sam sam sam std A sam std std In the above equation, std and sam stands for standard and sample. η, A, Φ and m stands for refractive index of the solvent, absorbance at excitation wavelength, singlet oxygen quantum yield and slope of the absorbance of DPBF changing with time, respectively. For measurement, m m 2 (3) 3

4 optically matched solutions of sample and standard were used. DiiodoBodipy was used as standard ( = 85% in toluene) for the measurement of the singlet oxygen quantum yield. The nanosecond transient absorption spectra were measured on an LP980 laser flash photolysis spectrometer (Edinburgh Instruments, UK). The samples were excited with a nanosecond pulsed laser (polette 355II+UV nanosecond pulsed laser, the wavelength is tunable in the range of nm, PTEK, UA) and the signal was digitized with a Tektronix TD 3012B oscilloscope. Each sample was purged with 2 in 15min before measurement. 2. yntheses of the Compounds cheme 1. ynthesis of PMI Derivatives a H a Br H b Br B c B F F BDP BPEA PMI--PTZ d e f Br PMI-Br PMI-C-PTZ PBI G5 B F F BDP-1 PMI-DPA a Key: (a) B, THF, ice bath, 1 h, under 2, yield: 20%; (b) n-c4h9br, KH, dry DMF, RT, overnight, under 2, yield: 88%; (c) bis(pinacolato)diboron, AcK, Pd(dppf)Cl2.CH2Cl2, 1,4-dioxane, 80 C, 18 h, yield: 45%; (d) phenothiazine, tri-tert-butylphosphine, sodium tert-butoxide, Pd2(dba)3, dry toluene, 80 C, 8 h, under 2, yield: 61%; (e) compound 3, K2C3, Pd(PPh3)4, DMF/H2, 80 C, 3 h, under 2, yield: 42%; (f) diphenylamine, similar to step (d), yield: 55%. 4

5 Compound PMI--PTZ. Compound PMI-Br (100 mg, 0.18 mmol), phenothiazine (42.6 mg, 0.21 mmol) and sodium tert-butoxide (51.3 mg, 0.53 mmol) were mixed together with dry toluene (5 ml) in a 25 ml two-necked round bottom flask under 2 atmosphere. Then Pd2(dba)3 (8.1 mg, 0.01 mmol) and tri-tert-butyl phosphine (4.4 mg, 0.02 mmol) were added and the reaction mixture was stirred at 80 C under 2 for 9 h. Water (5 ml) and CH2Cl2 (25 ml) were added after the reaction mixture was cooled down to room temperature. The organic layer was washed with saturated acl solution (3 30 ml) and dried over anhydrous a24. After the solvent was removed under reduced pressure, the crude product was purified with column chromatography (silica gel, petroleum ether/ch2cl2 = 2:3, v/v) to give a dark brown solid (74.2 mg, yield: 61%). Mp: > 250 C. 1 H MR (CDCl3, 400 MHz): 8.74 (t, 3H, J = 8.0 Hz), 8.58 (m, 3H), 8.27 (d, 1H, J = 8.0 Hz), 7.85 (d, 1H, J = 8.0 Hz), 7.67 (t, 1H, J = 8.0 Hz), 7.51 (t, 1H, J = 8.0 Hz), 7.35 (d, 2H, J = 4.0 Hz), 7.09 (d, 2H, J = 8.0 Hz), 6.83 (t, 4H, J = 8.0 Hz), 6.20 (d, 2H, J = 4.0 Hz), (m, 2H), 1.20 (d, 12H, J = 4.0 Hz). 13 C MR (CDCl3, 126 MHz): , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , 31.59, 29.17, 24.04, 22.66, HRM (MALDI-TF): Calcd ([C46H3422] ), m/z = ; found, m/z = Compound PMI-C-PTZ. Compound PMI-Br (100 mg, 0.18 mmol), 10-butyl-3-(4,4,5-trimethyl- 1,3,2-dioxaborolan-2-yl)-10H-phenothiazine (81.5 mg, 0.22 mmol), K2C3 (89.0 mg, 0.64 mmol), DMF (5 ml) and water (0.5 ml) were mixed together in a 25 ml two-necked round bottom flask under 2 atmosphere. After bubbling, the Pd(PPh3)4 (10.3 mg, 0.01 mmol) was added and the reaction mixture was stirred at 80 C under 2 for 3 h. Water (30 ml) was added after the reaction mixture was cooled down to room temperature. The aqueous layer was extracted with CH2Cl2 (3 50 ml). The organic layers were combined and dried over anhydrous a24. After the solvent was removed under reduced pressure, the crude product was purified with column chromatography (silica gel, petroleum ether/ch2cl2 = 1:10, v/v) to give a dark red solid (55.1 mg, yield: 42%). Mp: C. 1 H MR (CDCl3, 400 MHz):

6 (d, 2H, J = 8.0 Hz), (m, 4H), 8.07 (d, 1H, J = 4.0 Hz), 7.61 (t, 1H, J = 8.0 Hz), 7.55 (d, 1H, J = 4.0 Hz), 7.49 (t, 1H, J = 4.0 Hz), (m, 4H), 7.19 (d, 2H, J = 4.0 Hz), 6.99 (d, 3H, J = 32.0 Hz), 4.08 (s, 2H), (m, 2H), 1.87 (s, 2H), (m, 2H), 1.20 (d, 12H, J = 8.0 Hz), 1.02 (t, 3H, J = 4.0 Hz). 13 C MR (CDCl3, 126 MHz): , , , , , , , , , , , , , , , , , , , , 29.76, 29.14, 24.03, 20.27, HRM (MALDI-TF): Calcd ([C50H4222] ), m/z = ; found, m/z = Compound PMI-DPA. Compound PMI-Br (100 mg, 0.18 mmol), diphenylamine (36.2 mg, 0.21 mmol) and sodium tert-butoxide (51.3 mg, 0.53 mmol) were mixed together with dry toluene (5 ml) in a 25 ml two-necked round bottom flask under 2 atmosphere. Then Pd2(dba)3 (8.1 mg, 0.01 mmol) and tri-tert-butyl phosphine (4.4 mg, 0.02 mmol) was added and the reaction mixture was stirred at 80 C under 2 for 9 h. Water (4 ml) and CH2Cl2 (25 ml) were added after the reaction mixture was cooled down to room temperature. The organic layer was washed with saturated acl solution (3 30 ml) and dried over anhydrous a24. After the solvent was removed under reduced pressure, the crude product was purified with column chromatography (silica gel, petroleum ether/ch2cl2 = 1:3) to give a dark purple solid (64.0 mg, yield: 55%). Mp: > 250 C. 1 H MR (CD2Cl2, 400 MHz): 8.66 (s, 2H), 8.55 (d, 4H, J = 8.0 Hz), 8.13 (d, 1H, J = 8.0 Hz), (m, 2H), 7.47 (s, 1H), 7.40 (d, 2H, J = 8.0 Hz), 7.33 (t, 4H, J = 8.0 Hz), (m, 6H), (m, 2H), 1.19 (d, 12H, J = 8.0 Hz). 13 C MR (CDCl3, 126 MHz): , , , , , , , , , , , , , , , , , , , , , , , , , , , 31.59, 29.12, 24.03, 22.65, HRM (MALDI-TF): Calcd ([C46H3622] ), m/z = ; found, m/z = Compound 1. Under 2 atmosphere, the phenothiazine (2.0 g, 10.0 mmol) was dissolved in dry THF (20 ml) in a double-necked round-bottomed flask. Then B (1.8 g, 10.0 mmol) was also dissolved in dry THF (20 ml) and added dropwise over 1 h with an additional funnel. The reaction mixture was stirred 6

7 under the ice bath and quenched by water (40 ml) after the addition of B was completed. The aqueous layer was extracted by DCM (3 50 ml). The organic layer was combined and dried over anhydrous a24 and the solvent was removed under reduced pressure. The residue was purified by column chromatography (silica gel, n-hexane/ethyl acetate = 8:1) to give a light green solid (555 mg, yield 19.9%). 1 H MR (DM-d6, 400 MHz): s, 1H m, 2H m, 1H d, 1H, J = 8.0 Hz m, 1H d, 1H, J = 8.0 Hz d, 1H, J = 8.0 Hz HRM (EI): Calcd ([C12H8Br H] ), m/z = ; found, m/z = Compound 2. Under 2 atmosphere, the mixture of 1 (1.0 g, 3.6 mmol), anhydrous potassium hydroxide (303 mg, 5.4 mmol) and dry DMF (5 ml) were added and stirred at 0 C for 10 min. Then 1- bromobutane (0.47 ml, 4.3 mmol) was added dropwise to the reaction mixture and stirred at room temperature for 13 h. After the reaction was finished (monitored via TLC), the mixture was poured to the ice water (30 ml) and extracted with DCM (3 30 ml). rganic layer was dried over anhydrous a24 and the solvent was removed under reduced pressure. The residue was purified with column chromatography (silica gel, petroleum ether) to give a yellow oil (1.06 g, yield 88%). 1 H MR (CDCl3, 400 MHz): m, 2H m, 2H t, 1H, J = 8.0 Hz d, 1H, J = 8.0 Hz d, 1H, J = 8.0 Hz s, 2H m, 2H m, 2H t, 3H, J = 8.0 Hz HRM (EI): Calcd ([C16H16Br] + ), m/z = ; found, m/z = Compound 3. Under 2 atmosphere, the mixture of 2 (333 mg, 1 mmol), bis(pinacolato)diboron (381 mg, 1.5 mmol), potassium acetate (245 mg, 2.5 mmol), Pd(dppf)Cl2.CH2Cl2 (24.5 mg, 0.03 mmol) and dry 1,4-dioxane (10 ml) were added and stirred at 80 C for 18 h. Then the reaction mixture was cooled to the room temperature, poured to the ice water (20 ml) and extracted with DCM (3 30 ml). rganic layer was washed with water (2 100 ml) and dried over anhydrous a24 and the solvent was removed under reduced pressure. The residue was purified with column chromatography (silica gel, petroleum ether: DCM = 3:2) to give a yellow oil (170 mg, yield 45%). 1 H MR (DM-d6, 400 MHz): m, 1H d, 1H, J = 4.0 Hz m, 1H m, 1H t, 2H, J = 8.0 7

8 Hz t, 1H, J = 8.0 Hz t, 2H, J = 8.0 Hz m, 2H m, 2H s, 12H t, 3H, J = 8.0 Hz HRM (EI): Calcd ([C22H28B2] + ), m/z = ; found, m/z =

9 3. Molecular tructure Characterization Data TM H Br Water Chemical hift (ppm) Figure 1. 1 H MR spectrum of compound 1 (DM-d6, 400 MHz) zyj-m279-neg #5-6 RT: AV: 2 B: L: 7.24E6 T: FTM - p EI Full ms [ ] [M H] H Br Relative Abundance m/z Figure 2. EI-HRM spectrum of compound 1. 9

10 Br Chemical hift (ppm) Figure 3. 1 H MR spectrum of compound 2 (CDCl3, 400 MHz). Br M + Figure 4. TF-HRM spectrum of compound 2. 10

11 DM Water B Chemical hift (ppm) Figure 5. 1 H MR spectrum of compound 3. (DM-d6, 400 MHz). B M + Figure 6. TF-HRM spectrum of compound 3. 11

12 Chemical hift (ppm) Figure 7. 1 H MR spectrum of compound PMI--PTZ (CDCl3, 400 MHz) Chemical hift (ppm) Figure C MR spectrum of PMI--PTZ (CDCl3, 126 MHz). 12

13 ZYJ-3(CHCA) (0.832) TF LD M e % m/z Figure 9. MALDI-HRM spectrum of PMI--PTZ Chemical hift (ppm) Figure H MR spectrum of PMI-C-PTZ (CDCl3, 400 MHz). 13

14 Figure C MR spectrum of PMI-C-PTZ (CDCl3, 126 MHz). ZYJ (0.766) TF LD e M % Chemical hift (ppm) m/z Figure 12. MALDI-HRM spectrum of PMI-C-PTZ. 14

15 TM Chemical hift (ppm) Figure H MR spectrum of PMI-DPA (CD2Cl2, 400 MHz) Chemical hift (ppm) Figure C MR spectrum of PMI-DPA (CDCl3, 126 MHz). 15

16 ZYJ (0.897) TF LD M e % m/z Figure 15. MALDI-HRM spectrum of PMI-DPA Br Chemical hift (ppm) Figure H MR spectrum of PMI-Br (CDCl3, 400 MHz). 16

17 4. UV Vis Absorption pectra Absorbance 0.4 a n-hex TL DCM 0.3 THF MeC Absorbance 0.4 b n-hex TL DCM 0.3 THF MeC Absorbance 0.4 c n-hex TL DCM THF MeC 0.1 Absorbance d n-hex TL DCM THF MeC Figure 17. UV Vis absorption spectra of (a) PMI--PTZ; (b) PMI-C-PTZ; (c) PMI-DPA and (d) PMI-Br in different solvents. c = M, 20 C. 17

18 5. Fluorescence pectra Intensity / a.u a HEX TL DCM THF MeC Intensity / a.u b HEX TL DCM THF MeC Intensity / a.u c HEX TL DCM THF MeC Intensity / a.u d HEX TL DCM THF MeC Figure 18. Fluorescence emission spectra of (a) PMI--PTZ (λex = 465 nm, A = 0.302); (b) PMI-C- PTZ (λex = 450 nm, A = 0.104); (c) PMI-DPA (λex = 460 nm, A = 0.101) and (d) PMI-Br (λex = 440 nm, A = 0.160) in different solvents. ptically matched solutions were used (the concentration is varied slightly for the compounds). 20 C. 18

19 Counts nm = 10.4 ns a 507 nm = 4.4 ns Counts nm = 4.8 ns b 505 nm = 5.4 ns Counts nm = 5.3 ns c 504 nm = 4.6 ns Time / ns Time / ns Time / ns Figure 19. The fluorescence decays of (a) PMI--PTZ; (b) PMI-C-PTZ; (c) PMI-DPA. ex = 445 nm. c = M for PMI--PTZ and PMI-C-PTZ, and c = M for PMI-DPA in deaerated n- hexane. 20 C. 6. inglet xygen Quantum Yield Table 1. inglet xygen Quantum Yields of PMI Derivatives in Different olvents a n-hexane Toluene DCM THF MeC PMI--PTZ b b b PMI-C-PTZ b PMI-DPA b b 1.2 PMI-Br a In percentage, ex = 500 nm. DiiodoBodipy was used as standard compound, = 85% in toluene. b ot observed. 19

20 7. anosecond Time-resolved Transient Absorption pectra.d ns 10 s 50 s 100 s 200 s a b.d c d.d e 5 ns 5 s 10 s 20 s 50 s f.d nm = 123 s.d D nm = 37 s nm = 44 s Time / s Time / s Time / s Figure 20. anosecond transient absorption spectra of (a) PMI-C-PTZ ( ex = 532 nm, c = M in deaerated toluene) and (b) the related decay trace at 590 nm; (c) PMI-DPA ( ex = 532 nm, c = M in deaerated n-hexane) and (d) the related decay trace at 480 nm. (e) PMI-Br ( ex = 532 nm, c = M in deaerated acetonitrile) and (f) the related decay trace at 550 nm. 20 C. 20

21 0.10 a 0.03 b.d nm = 120 ns.d nm = 151 ns Time / ns Time / ns Figure 21. The decay trace of triplet state of (a) PMI--PTZ ( ex = 500 nm, c = M in aerated n-hexane); (b) PMI-C-PTZ ( ex = 532 nm, c = M in aerated toluene). 20 C. 21

22 8. Delayed Fluorescence pectra a c e C.p.s C.p.s 400 C.p.s b d f Counts nm = 3.41 ns Counts nm = 4.36 ns Counts nm = 4.15 ns Time / ns Time / ns Time / ns Figure 22. The fluorescence emission spectra of (a) BPEA and (b) the related decay at 476 nm; (c) PBI and (d) the related decay trace at 519 nm; (e) G5 and (f) the related decay trace at 500 nm. c = M in n-hexane. 20 C. 22

23 Intensity / a.u a 0 μs 20 μs 260 μs 280 μs Intensity / a.u c 0 μs 8 μs 104 μs 112 μs Intensity / a.u = 8.7 s b In 2 In air 2 = 44.1 s Intensity / a.u = 4.7 s d In 2 In air 2 = 21.2 s Time / s Time / s Figure 23. Delayed fluorescence spectra of the mixture of PMI--PTZ with (a) PBI (c = M) and (b) the related decay trace at 520 nm; (c) G5 (c = M) and (d) the related decay trace at 510 nm. PMI--PTZ was used as photosensitizer (c = M, ex = 500 nm). The spike in the delayed fluorescence traces is the scattered laser. 20 C. 23

24 9. Discussion on the Decay of the Charge eparated tates (C) of the Dyads The decay of the C of the dyads include a few processes (please refer to the cheme 2 in the main text), i. e. the IC process giving the localized triplet state; the radiative decay to the ground state (0), and the non-radiative to the ground state. All these processes for the decay of the C of the dyads are actually charge recombination, i.e. the electron transfer. The Marcus theory for the electron transfer kinetics predicts that there is no simple exponential relationship between the energy gap of the states (herein it is the energy gap between the C and the ground state). Moreover, it is inappropriate to compare the non-radiative decay rate constants of the different compounds, based on the different energy gaps. The reason is that other factors, such as the reorganization energy ( ) and the electronic coupling between the electron donor and acceptors (VDA). These parameters all contribute to the electron transfer rate constants (related to the non-radiative decay of the dyads in this manuscript), and these parameters are different for the dyads. The relationship between the energy gap (can be approximated as the Gibbs free energy changes of the electron transfer) and the electron transfer rate constant is described by the Marcus equation 4: [1] k et 2 V exp - h k T 1 2 B 2 G / 4 kbt (4) G is the Gibbs free energy change between the equilibrium reactant and the product state; is the total reorganization energy; V is the electronic coupling matrix element. T is the temperature and the kb is the Boltzmann constant. 24

25 10. DFT ptimized Ground tate Geometry. (a) (b) (c) Figure 24. ptimized ground state conformations and the dihedral angles of (a) PMI--PTZ; (b) PMI- C-PTZ and (c) PMI-DPA calculated with DFT theory at B3LYP/6-31G (d) level with Gaussian 09W. 11. Fluorescence Excitation pectra. ormalized intensity / a.u a Absorption Excitation ormalized intensity / a.u b Absorption Excitation ormalized intensity / a.u c Absorption Excitation Figure 25. ormalized fluorescence excitation spectra and UV Vis absorption spectra. (a) PMI--PTZ ( em = 750 nm); (b) PMI-C-PTZ ( em = 730 nm) and (c) PMI-DPA ( em = 750 nm) in n-hexane. c = M, 20 C. 25

26 12. x,y,z Coordinates of the ptimized Ground tate Geometry of the Compounds PMI--PTZ Charge = 0; Multiplicity = 1 ymbolic Z-Matrix: C C C PMI--PTZ C C C C C H H H C C C C C C C C H H C C

27 C C H H C H C C C C C C H H H C H C H C H H H C H H H C H

28 H H C H H H C H C C C C C C C C C H C C H H H H H H C H

29 Calculation Type = FREQ Calculation Method = RB3LYP Basis et = 6 31G(d) Charge = 0 pin = inglet E(RB3LYP) = a.u. RM Gradient orm = a.u. Imaginary Freq = 0 Dipole Moment = Debye Point Group = C1 PMI-C-PTZ Charge = 0; Multiplicity = 1 ymbolic Z-Matrix: C C C C C C PMI-C-PTZ C C H H H C C

30 C C C C C C H H C C C C H H C H C C C C C C H H H

31 C H C H C H H H C H H H C H H H C H H H C H C C C C C C

32 C C C H C C C H H H H H H C H H C H H C H H C H H H

33 Calculation Type = FREQ Calculation Method = RB3LYP Basis et = 6 31G(d) Charge = 0 pin = inglet E(RB3LYP) = a.u. RM Gradient orm = a.u. Imaginary Freq = 0 Dipole Moment = Debye Point Group = C1 PMI-DPA Charge = 0; Multiplicity = 1 ymbolic Z-Matrix: C C C C C PMI-DPA C C C H H H C

34 C C C C C C C H H C C C C H H C C C H C H C H H

35 C C C C H C H C H H H C H C C C C C C H H H C H C H C H

36 H H C H H H C H H H C H H H C H C H Calculation Type = FREQ Calculation Method = RB3LYP Basis et = 6 31G(d) Charge = 0 pin = inglet E(RB3LYP) = a.u. RM Gradient orm = a.u. Imaginary Freq = 0 Dipole Moment = Debye Point Group = C1 36

37 13. Reference [1] J. W. Verhoeven, J. Photochem. Photobio C: Photochem Rev., 2006, 7,