SUPPORTING INFORMATION Polyimide and Imide Compound Exhibiting Bright Red Fluorescence with Very Large Stokes Shifts via Excited-State Intramolecular Proton Transfer II. Ultrafast Proton Transfer Dynamics in the Excited-State Kenta Kanosue 1, Ramūnas Augulis 2, Domantas Peckus 2,3, Renata Karpicz 2, Tomas Tamulevičius 3, Sigitas Tamulevičius 3, Vidmantas Gulbinas 2 *, and Shinji Ando 1 * 1 Department of Chemistry and Materials Science, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan 2 Center for Physical Sciences and Technology, Savanorių Ave. 231, Vilnius LT-02300, Lithuania 3 Institute of Materials Science, Kaunas University of Technology, K. Baršausko g. 59, Kaunas LT- 51423, Lithuania *Corresponding authors: E-mail: sando@polymer.titech.ac.jp; vidgulb@ktl.mii.lt tel.: +81-3-5734-2137; fax: +81-3-5734-2889 S1
Materials Bromodurene (1), purchased from Aldrich, was used as received. Cyclohexylamine, purchased from Kanto Chemical Co., Inc., was purified by distillation under reduced pressure. 4,4 - Diaminocyclohexylmethane (DCHM), purchased from Tokyo Kasei Kogyo Co., Ltd., was purified by recrystallization from n-hexane and subsequent sublimation under reduced pressure. N,O- Bis(trimethylsilyl)trifluoroacetamide (BSTFA, 99%) and N,N-dimethylacetamide (DMAc, anhydrous), purchased from Aldrich, were used as received. Synthesis of Model Compound 3-Bromopyromellitic Acid (2) 1,2 The synthetic scheme of 3H-MC is shown in Scheme S1. Compound 1 (6.60 g, 31.0 mmol) was dissolved in pyridine (50 ml). A hot solution of potassium permanganate (65 g, 411 mmol) in water (300 ml) was added to the pyridine solution and refluxed at 115 C under a N 2 flow. Every 10 h, 10 g of potassium permanganate was added, and this was repeated four times. After the fourth addition, the solution was refluxed for an additional 10 h, cooled to room temperature, and filtered to remove deposited manganese dioxide. The filtrate was concentrated with a rotary evaporator and acidified with concentrated HCl to ph 1, and then the precipitate was filtered, washed with dilute HCl, and dried at 85 C for 6 h under vacuum. The white powder was purified by recrystallization from dilute HCl, and compound 2 was obtained (4.25 g, 12.7 mmol, 41% yield). Mp: 210 220 C (sublimated). 1 H NMR (400 MHz, DMSO-d 6, ppm): = 8.43 (s, 1H). 13 C NMR (100 MHz, DMSO-d 6, ppm): = 117.0, 129.3, 130.6, 142.2, 164.5, 167.1. S2
13 C NMR spectrum of compound 2. 3-Hydroxypyromellitic Acid (3) 3-5 Compound 2 (3.50 g, 10.5 mmol), sodium hydrate (1.12 g, 28.0 mmol), and sodium acetate (1.82 g, 22.1 mmol) were dissolved in water (100 ml), and 10 mg of Cu powder was added. The mixture was refluxed at 100 C for 35 h under a N 2 flow. The reaction solution was cooled to room temperature, filtered, concentrated with a rotary evaporator, and acidified with concentrated HCl. The faint yellow precipitate was filtered and dried at 85 C for 6 h under vacuum. The powder was purified by recrystallization from dilute HCl, and compound 3 was obtained (2.10 g, 7.8 mmol, 74% yield). Mp: 160 170 C (sublimated). 1 H NMR (400 MHz, DMSO-d 6, ppm): = 7.58 (s, 1H). 13 C NMR (100 MHz, DMSO-d 6, ppm): = 120.2, 125.9, 132.1, 153.7, 166.5, 167.7. S3
13 C NMR spectrum of compound 3. 3-Hydroxypyromellitic Dianhydride (PHDA, 4) Compound 3 (2.00 g, 7.4 mmol) was heated at 180 C for 8 h under reduced pressure, yielding PHDA (1.47 g, 6.3 mmol, 85% yield). Mp: 200 210 C (sublimated). 1 H NMR (400 MHz, acetone-d 6, ppm): = 8.11 (s, 1H). Elemental analysis (%) calcd for C 10 H 2 O 7 : C 51.30, H 0.86, O 47.84; found: C 49.61, H 1.40, O 48.99. HRMS (EI) m/z [M] + calcd for C 10 H 2 O 7 233.9801; found 233.9796. The 13 C NMR spectrum of PHDA could not be measured due to its poor solubility. Imide Model Compound (3H-MC) A precursor of 3H-MC, amic acid silyl ester, was prepared through the in situ silylation method. 6,7 Cyclohexylamine (840 mg, 8.5 mmol) and BSTFA (1,044 mg, 4.0 mmol) were stirred for 30 min in DMAc (12 ml) (solution I). PHDA (1,000 mg, 4.3 mmol) was stirred for 30 min in DMAc (12 ml) (solution II). Solutions I and II were mixed and then stirred overnight in an ice bath. After distillation of DMAc under reduced pressure, propionic acid (30 ml) was added and the mixture was refluxed at 140 C for 6 h under a N 2 flow. After cooling to room temperature, the yellow solid reprecipitated by excess water was filtered and dried at 120 C under vacuum. Yellow crystals of 3H-MC were obtained by S4
recrystallization from o-dichlorobenzene (955 mg, 2.4 mmol, 56% yield). Mp: 210 220 C (sublimated). 1 H NMR (400 MHz, CDCl 3 -d, ppm) = 1.2 1.4 (m, 6H), 1.6 1.9 (m, 10H), 2.1 2.3 (m, 4H), 4.10 (m, 2H), 7.75 (s, 1H). Elemental analysis (%) calcd for C 22 H 24 N 2 O 5 : C 66.65, H 6.10, N 7.07, O 20.18; found: C 65.37, H 5.80, N 6.60, O 22.23. HRMS (EI) m/z [M] + calcd for C 22 H 24 N 2 O 5 396.1685; found 396.1682. The 13 C NMR spectrum of 3H-MC could not be measured due to its poor solubility. Scheme S1. Synthetic scheme of 3H-MC. Preparation of 3H-PI Film The synthetic scheme of 3H-PI is shown in Scheme S2. The precursor of PI, poly(amic acid) silyl ester, was also prepared using the in situ silylation method. DCHM (500 mg, 2.3 mmol) and BSTFA (642 mg, 2.5 mmol) were stirred in DMAc (7 ml) for 30 min. PHDA (538 mg, 2.3 mmol) was added to the solution and then stirred overnight. The resulting viscous yellow solution was spin-coated onto a fused silica (amorphous SiO 2 ) substrate, followed by soft-baking at 70 C for 1 h and subsequent thermal imidization via a one-step imidization procedure; the final curing conditions were 220 C for 1.5 h under a N 2 flow. The heating rate from 70 C to 220 C was 4.6 C/min. The film thickness of 3H- PI was estimated to be 4.2 m. S5
Scheme S2. Synthetic scheme of 3H-PI. S6
Figure S1. Excitation/emission spectra of 3H-MC dissolved in CHCl 3. Spectra were measured by monitoring ex of 367 nm and em of 592 nm, respectively. S7
Figure S2. Calculated molecular orbitals of 3H-MC enol and keto forms (TD-DFT method at B97X- D/6-311++G(d,p) level). HOMO m and LUMO +m denote the (m + 1)th highest occupied orbital and the (m + 1)th lowest unoccupied orbital, respectively. S8
Figure S3. Concentration-dependent UV-vis spectra of 3H-MC dissolved in CHCl 3. Spectra were normalized to the absorbance of the enol LE( *) absorption band. Figure S4. TGA curve of 3H-PI film measured with heating rate of 5 C/min. S9
Figure S5. Steady-state emission spectra of 3H-PI film at lower temperatures when excited at 365 nm. S10
Figure S6. TA spectra and temporal behaviors of 3H-PI film when excited at 455 nm. (a) Spectrum at each delay time and (b) temporal behavior at each wavelength. S11
REFERENCES (1) Giesa, R.; Keller, U.; Eiselt, P.; Schmidt, H. W. J. Polym. Sci. Part A: Polym. Chem. 1993, 31, 141-151. (2) Holy, P.; Sehnal, P.; Tichy, M.; Zavada, J.; Cisarova, I. Tetrahedron: Asymmetry 2004, 15, 3805-3810. (3) Field, L.; Engelhardt, P. R. J. Org. Chem. 1970, 35, 3647-3655. (4) Miura, Y.; Torres, E.; Panetta, C. A. J. Org. Chem. 1988, 53, 439-440. (5) Zhao, Y.; Wu, H.; Emge, T. J.; Gong, Q.; Nijem, N.; Chabal, Y. J.; Kong, L.; Langreth, D. C.; Liu, H.; Zeng, H.; Li, J. Chem Eur. J. 2011, 17, 5101-5109. (6) Oishi, Y.; Ogasawara, K.; Hirahara, H.; Mori, K. J. Photopolym. Sci. Technol. 2001, 14, 37-40. (7) Oishi, Y.; Kikuchi, N.; Mori, K.; Ando, S.; Maeda, K. J. Photopolym. Sci. Technol. 2002, 15, 213-214. S12