Tunable Visible Light Emission of Self-Assembled Rhomboidal Metallacycles J. Bryant Pollock,* Gregory L. Schneider, Timothy R. Cook, Andrew S. Davies, Peter J. Stang* Department of Chemistry, University of Utah; 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112 Stang@chem.utah.edu Bryant@chem.utah.edu 1. Materials and Experimental Procedures S2 2. 1 H NMR Spectra of Ligands 1, 2, 4 and 5 S7 3. 1 H and 31 P{ 1 H} NMR and ESI-MS Spectra of 7 S11 4. 1 H and 31 P{ 1 H} NMR and ESI-MS Spectra of 8 S13 5. 1 H and 31 P{ 1 H} NMR and ESI-MS Spectra of 10 S15 6. 1 H and 31 P{ 1 H} NMR and ESI-MS Spectra of 11 S17 7. UV/Vis and Emission Spectra of 1-5 S19 8. UV/Vis Spectrum of 6 S20 9. UV/Vis and Emission Spectra of 9 in Various Solvents S20 10. References S21 S1
Experimental: Materials and Methods: 2,6-bis(pyrid-4ylethynyl) aniline (3), 1 2,9-bis[trans-Pt(PEt 3 ) 2 NO 3 ] phenanthrene (6), 2 and complex 9 1 were prepared using known procedures. All chemicals were purchased from Sigma- Aldrich, Oakwood Chemicals, Alfa Aesar and TCI America while deuterated solvents were purchased from Cambridge Isotope Laboratory (Andover, MA). 1 H and 31 P{ 1 H} NMR spectra were recorded on a Varian 300 spectrometer and the mass spectra were recorded on a Micromass LCT Premier XE ToF mass spectrometer using electrospray ionization and analyzed using the MassLynx software suite; high resolution mass spectrometry (HRMS) ESI-ToF with a mass accuracy within 0.003 m/z unit of the theoretical value was utilized to support the chemical formula for 1, 2, 4 and 5. The ESI-MS samples for 7, 8, 10 and 11 were dissolved in methylene chloride then diluted with acetone unless otherwise noted. All 31 P{ 1 H} NMR spectra were referenced using a 10% H 3 PO 4 aq solution. Elemental Analysis was performed by Atlantic Microlab, Inc. General Procedure for the Synthesis of 1, 2 and 4: To a Schlenk flask, 200 mg (0.76 mmol) of 2,6-dibromo-4-methylaniline, 200 mg (0.63 mmol) of 2,6-dibromo-4-trifluoromethylaniline, or 200 mg (0.51 mmol) of 2,6-diiodo-4-nitroaniline were weighed with 6 equivalents of 4-ethynylpyridine hydrochloride, 5 mol% of copper iodide, and 5 mol% of palladium tetrakis(triphenylphosphine). The Schlenk flask was then evacuated and put under inert N 2 atm. 20 ml of dimethylformamide (DMF) and 10 ml of triethylamine S2
(Et 3 N) that was sitting on a bed of potassium hydroxide (KOH) were sparged with N 2 for 30 min and syringed into the Schlenk flask. The reaction was heated to 80 C and allowed to stir for 48 h in the dark. The solution was then cooled to room temperature and poured into a separatory funnel containing sat. sodium bicarbonate (NaHCO 3 ), which was then extracted with ethyl acetate (EtOAc). The organic layer was then rotovaped and subjected to column chromatography using 5% methanol (MeOH) in dichloromethane (DCM) as the mobile phase. The product was obtained as a yellow solid and recrystallized using a MeOH/H 2 O mixture. 1: (15%). 1 H NMR (dmso-d 6 ; 300 MHz); 8.66-8.64 (d, 4H, Py α, J=6 Hz); 8.27 (s, 2H, ArH); 7.70-7.69 (d, 4H, Py β, J=3 Hz); 7.39 (bs, 2H, NH 2 ); HRMS (ESI-ToF) m/z: [M-H] - Calc d for C 20 H 11 N 4 O 2 [339.0882]; Found 339.0884 2: (27%). 1 H NMR (dmso-d 6 ; 300 MHz); 8.64-8.63 (d, 4H, Py α, J=3 Hz); 7.73 (s, 2H, ArH); 7.66-7.65 (d, 4H, Py β, J=3 Hz); 6.74 (bs, 2H, NH 2 ); HRMS (ESI-ToF) m/z: [M+H] + Calc d for C 21 H 13 F 3 N 3 [364.1062]; Found 364.1069 4: (28%). 1 H NMR (dmso-d 6 ; 300 MHz); 8.61-8.59 (d, 4H, Py α, J=6 Hz); 7.60-7.58 (d, 4H, Py β, J=6 Hz); 7.25 (s, 2H, ArH); 5.83 (bs, 2H, NH 2 ); 2.15 (s, 3H, ArCH 3 ); HRMS (ESI-ToF) m/z: [M+H] + Calc d for C 21 H 16 N 3 [310.1344]; Found 310.1354 2,6-bis(4-ethynylpyridine)-4-aminoaniline (5): 330 mg (0.97 mmol) of 1 was weighed into a 50 ml round bottom flask and suspended in 20 ml of DMF and 5 ml of ethanol (EtOH). 2.19 g (9.71 mmol) of stannous chloride dihydrate (SnCl 2 2H 2 O) was then added slowly. The mixture was heated to 90 C and allowed to stir for 24 h. Upon cooling, the mixture was filtered and poured into ~50 ml of EtOAc. The solution was S3
then extracted with ~50 ml of H 2 O multiple times. The organic layer was collected and rotovaped. The solid was purified via chromatography using a 5% MeOH/DCM mobile phase. The product was then recrystallized in a MeOH/H 2 O solution to afford the pure product as an orange solid. (54%). 1 H NMR (dmso-d 6 ; 300 MHz); 8.60-8.59 (d, 4H Py α, J=3 Hz); 7.57-7.55 (d, 4H Py α, J=6 Hz); 6.74 (s, 2H, ArH); 5.20 (bs, 2H NH 2 ); 4.64 (bs, 2H NH 2 ); HRMS (ESI-ToF) m/z: [M+H] + Calc d for C 20 H 15 N 4 [311.1297]; Found 311.1302 General Procedure for 7-8 and 10-11: To a 2 dram vial, 1.17 mg (3.45 µmol) of 1, 1.25 mg (3.45 µmol) of 2, 1.07 mg (3.45 µmol) of 4, or 1.07 mg (3.45 µmol) of 5 was weighed with 4.00 mg (3.45 µmol) of 6. ~1 ml of MeOH was then added and the vial was capped. The mixture was then heated to ~50 C and allowed to stir for 24 h. Upon cooling, the solution was dried overnight and then redissolved in methylene chloride-d 2 (CD 2 Cl 2 ) for characterization. For further purification, if needed, ethyl ether was added to precipitate the complex. Centrifugation and decanting the supernatant afforded the complex as a pure solid. (>95%) 7: 1 H NMR (CD 2 Cl 2 ; 300 MHz); 8.91-8.92 (d, 4H Py α, J=3 Hz); 8.71-8.73 (d, 4H Py α, J=6 Hz); 8.58 (s, 4H PhenH); 8.43 (s, 4H, ArH); 8.38-8.39 (d, 4H Py β, J=3 Hz); 7.77-7.79 (d, 4H, Py β, J=6 Hz); 7.65-7.66 (8H PhenH); 7.62 (s, 4H PhenH); 7.44 (bs, 4H NH 2 ); 1.37 (bs, 48H PCH 2 CH 3 ); 1.19 (m, 72H PCH 2 CH 3 ). 31 P{ 1 H} NMR (CD 2 Cl 2, 121.4 MHz) δ 12.70 (bs; 195 Pt satellites, J Pt-P, 2685 Hz); ESI-MS: C 116 H 160 N 3 O 16 P 8 Pt 4 ; [M 3 ONO 2 ] 3+ 939.96; Elemental Analysis: Calcd: [7] + CH 2 Cl 2 ; C, 45.45; H, 5.28; N, 5.44; Found: C, 45.57; H, 5.61; N, 5.28. 8: 1 H NMR (CD 2 Cl 2 ; 300 MHz); 8.88-8.90 (d, 4H Py α, J=6 Hz); 8.69-8.71 (d, 4H Py α, J=6 Hz); 8.43 (s, 4H PhenH); 8.34-8.37 (d, 4H Py β, J=9 Hz); 7.77 (m, 4H, Py β and 4H ArH); 7.65-7.66 (d, 8H PhenH, J=3 Hz); 7.62 (s, 4H PhenH); 6.85 (bs, 4H NH 2 ); 1.37 (bs, 48H PCH 2 CH 3 ); 1.19 (m, 72H PCH 2 CH 3 ). 31 P{ 1 H} NMR (CD 2 Cl 2, 121.4 MHz) δ 16.72 (bs; 195 Pt satellites, J Pt-P, 2678 Hz); ESI-MS: C 118 H 160 F 6 N 10 O 12 P 8 Pt 4 ; [M 3 ONO 2 ] 3+ 955.28; Elemental Analysis: Calcd: [8] + 2 CH 2 Cl 2 ; C, 44.72; H, 5.13; N, 4.35; Found: C, 45.00; H, 5.54; N, 4.36. 10: 1 H NMR (CD 2 Cl 2 ; 300 MHz); 8.90-8.92 (d, 4H Py α, J=6 Hz); 8.65-8.67 (d, 4H Py α, J=6 Hz); S4
8.62 (s, 4H PhenH); 8.22-8.24 (dd, 4H Py β, J=6 Hz); 7.72-7.74 (dd, 4H, Py β ); 7.64-7.66 (d, 12H PhenH, J=6 Hz); 7.61 (s, 4H ArH); 7.38 (bs, 4H NH 2 ); 2.29 (s, 6H CH 3 ); 1.37 (bs, 48H PCH 2 CH 3 ); 1.18 (m, 72H PCH 2 CH 3 ); 3.35 (q, diethyl ether). 31 P{ 1 H} NMR (CD 2 Cl 2, 121.4 MHz) δ 12.72 (bs; 195 Pt satellites, J Pt-P, 2682 Hz); ESI-MS: C 118 H 166 N 10 O 12 P 8 Pt 4 ; [M 3 ONO 2 ] 3+ 919.32; Elemental Analysis: Calcd: [10] + 2 CH 2 Cl 2 ; C, 46.27; H, 5.50; N, 4.50; Found: C, 46.00; H, 5.89; N, 4.53. 11: 1 H NMR (CD 2 Cl 2 ; 300 MHz); 8.96-8.98 (d, 4H Py α, J=6 Hz); 8.65 (m, 4H Py α and 4H PhenH); 8.16-8.18 (d, 4H Py β, J=6 Hz); 7.72-7.74 (d, 4H Py β ); 7.60-7.65 (d, 12H PhenH and 4H ArH, J=15 Hz); 7.00 (bs, 4H NH 2 ); 5.52 (bs, 4H NH 2 ); 1.37 (bs, 48H PCH 2 CH 3 ); 1.17 (m, 72H PCH 2 CH 3 ). 31 P{ 1 H} for NMR (CD 2 Cl 2, 121.4 MHz) δ 14.58 (bs; 195 Pt satellites, J Pt-P, 2688 Hz); ESI-MS: C 116 H 164 N 12 O 12 P 8 Pt 4 ; [M 3 ONO 2 ] 3+ 919.98; Elemental Analysis: Calcd: [11] + 2 CH 2 Cl 2 ; C, 45.47; H, 5.43; N, 5.39; Found: C, 45.15; H, 5.78; N, 5.55. Steady-State Absorption and Emission Spectroscopy and Quantum Yield Determination: Absorption and fluorescence spectra were recorded on a Hitachi U-4100 and Hitachi F-7000 Spectrophotometer, respectively, with aerated spectro-photometric grade methylene chloride, acetone, dimethylsulfoxide and methanol (Sigma Aldrich) at room temperature. The cells used in the experiments were 1 cm quartz cuvettes from Starna Cells, Inc. All samples were freshly prepared for each measurement. The molar absorption coefficients were determined by preparing four samples ranging in absorption from 0.01-1.0 in dimethylsulfoxide for ligands 1-5 and methylene chloride for 6-11. The molar absorption coefficients for each solution were then calculated using Beer s Law and the four were averaged. Subsequent samples were then prepared to confirm the molar absorption coefficients. Quantum yields were determined by, first, crosscalibrating the instrument with quinine sulfate in 0.1 M H 2 SO 4 and anthracene in ethanol. Quinine sulfate was then used to determine the experimental quantum yields at an excitation wavelength of 365 nm with Φ=0.55 for compounds 1-5 and 7-10; rhodamine 6G was used for 11 S5
at an excitation wavelength of 480 nm with Φ=0.95. The quantum yield measurements were performed in multiplicates with values that were within 10 % error being averaged. S6
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Figure S1: 1 H NMR spectra of 1. S8
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Figure S2: 1 H NMR spectra of 2. S10
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Figure S3: 1 H NMR spectra of 4. S12
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Figure S4: 1 H NMR spectra of 5. Figure S5: 1 H NMR Spectrum of 7. S14
Figure S6. 31 P{ 1 H} NMR Spectra of 7. Figure S7: ESI-MS Spectrum of [M 3 ONO 2 ] 3+ of 7. S15
Figure S8: ESI-MS Spectrum of 7. Figure S9: 1 H NMR Spectrum of 8. S16
Figure S10: 31 P{ 1 H} NMR Spectra of 8. S17
Figure S11: ESI-MS Spectrum of [M 3 ONO 2 ] 3+ of 8. Figure S12: ESI-MS Spectrum of 8. S18
Figure S13: 1 H NMR Spectra of 10. Figure S14: 31 P{ 1 H} NMR Spectra of 10. S19
Figure S15: ESI-MS Spectrum of [M 3 ONO 2 ] 3+ of 10. Figure S16: ESI-MS Spectrum of 10. S20
Figure S17: 1 H NMR Spectrum of 11. Figure S18: 31 P{ 1 H} NMR Spectrum of 11. S21
Figure S19: ESI-MS Spectrum of [M 3 ONO 2 ] 3+ of 11. Figure S20: ESI-MS Spectrum of 11. S22
Figure S21: UV/Vis (top) and emission (bottom) spectra for 1-5. 1 ( ), 2 ( ), 3 ( ), 4 ( ) and 5 ( ). S23
Figure S22: UV/Vis Spectrum of 6. Figure S22S23: UV/Vis and emission profiles for 9 in different solvents. MeOH ( ), Acetone ( ) and DMSO ( ). S24
References: (1) Pollock, J. B.; Cook, T. R.; Stang, P. J. J. Am. Chem. Soc. 2012, 134, 10607. (2) Kryschenko, Y. K.; Seidel, S. R.; Arif, A. M.; Stang, P. J. J. Am. Chem. Soc. 2003, 125, 5193. S25