Electronic Supplementary Material (ESI) for ChemComm. This journal is © The Royal Society of Chemistry 2018 Supporting Information for Fusing Triphenylphosphine with Tetraphenylborate: Introducing the 9- Phosphatriptycene-10-Phenylborate (PTB) Anion Marcus W. Drover,† Koichi Nagata,† and Jonas C. Peters* †These authors contributed equally *E-mail: [email protected] *Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, 91125, United States 1. General Considerations S2 2. Synthetic Procedures S3 3. Electrochemistry S30 4. Crystallography Discussion and Tables S31 5. Density Functional Theory S36 6. References S37 S1 General Considerations: All experiments were carried out employing standard Schlenk techniques under an atmosphere of dry nitrogen or argon employing degassed, dried solvents in a solvent purification system supplied by SG Water, LLC. Non-halogenated solvents were tested with a standard purple solution of sodium benzophenone ketyl in THF in order to confirm 1 effective moisture removal. P(o-BrC6H4)3 , 5-azoniaspiro[4.4]nonane bromide 2 ([ASN]Br) , and W(CO)5THF were prepared according to a literature procedure. All other reagents were purchased from commercial vendors and used without further purification unless otherwise stated. Physical methods: Fourier transform infrared ATR (FT-IR ATR) spectra were collected on a Bruker Alpha Platinum ATR spectrometer using OPUS software. NMR data were collected on a Varian 300 or 400 MHz instrument with chemical shifts reported in ppm relative to deuterated solvent, using residual solvent resonances as internal standards. 31P chemical shifts are reported in ppm relative to 85% aqueous H3PO4. UV-Visible spectroscopy measurements were collected with a Cary 50 UV-Vis spectrophotometer using a 1 cm two-window quartz cell. • 57Fe Mössbauer: Mössbauer spectra were recorded on a spectrometer from SEE Co. (Edina, MN) operating in the constant acceleration mode in transmission geometry. The sample was kept in an SVT-400 cryostat form Janis (Wilmington, MA), using liquid N2 as a cryogen for 80 K measurements. The quoted isomer shifts are relative to the centroid of the spectrum of a metallic foil of α-Fe at room temperature. Solution samples were transferred to a sample cup and chilled to 77 K inside of the glovebox, and quickly removed from the glovebox and immersed in liquid N2 until mounted in the cryostat. Data analysis was performed using WMOSS version 4 (www.wmoss.org) and quadrupole doublets were fit to Lorentzian lineshapes.3 S2 Synthetic Procedures: Li(THF)4 nBuLi (3.0 equiv.), -78 oC, 2 h P Br Br o PhBCl2, -78 C, 1.5 h P o o -78 C to 0 C, 12 h B 0 oC to r.t., 12 h Br Ph 5:1 Et2O/THF [3][Li(THF)4] (64%) Tetrakis(tetrahydrofuran) lithium phosphatriptycene-10-phenylborate ([3][Li(THF)4]): A solution of nBuLi (1.6 M, 1.1 mL, 1.7 mmol) in hexane was added dropwise to a solution 1 of tris(2-bromophenyl)phosphine (288 mg, 578.0 µmol) in Et2O (80 mL) and THF (24 mL) at –78 °C. Following addition, the resulting mixture was stirred for an additional 2 h ° at -78 C and a solution of PhBCl2 (70.0 µL, 578 µmol) in Et2O (20 mL) was added drop wise to the mixture at –78 °C. Subsequently, the mixture was allowed to warm to 0 °C and then stirred for an additional 24 h. Next, all volatiles were removed in-vacuo and the ® residue was dissolved in C6H6 and filtered though a pad of Celite . The resulting pale yellow solid was dissolved in THF and again filtered through a pad of Celite®. Concentration of the filtrate and cooling at –35 ºC afforded [3][Li(THF)4] as a pale yellow solid (238 mg, 64%). 1 3 H NMR (CD3CN, 400 MHz, 298 K): δ = 8.10 (br, 2H; o-Ph), 7.65 (d, JH,H = 7.2 Hz, 3 3 3H), 7.47 (br, 2H), 7.45 (t, JH,H = 7.2 Hz, 3H; m-Ph), 7.26 (t, JH,H = 7.2 Hz, 1H; p-Ph), 3 3 6.91 (t, JH,H = 7.2 Hz, 3H), 6.83 (t, JH,H = 7.2 Hz, 3H), 3.71 (m, 16H, THF), 1.84 (m, 16H, THF). 7 1 Li{ H} NMR (CD3CN, 156 MHz, 298 K): δ = – 1.2. 31 1 3 P{ H} NMR (THF-d8, 162 MHz, 298 K): δ = – 43.7 (d, JP,B = 3.8 Hz). 11 1 3 B{ H} NMR (CD3CN, 128 MHz, 298 K): δ = – 8.75 (d, JP,B = 3.8 Hz). 13 C NMR (THF-d8, 100 MHz, 298 K): δ = 147.3, 137.4, 132.1, 131.6, 131.5, 126.5, 124.9, 122.7, 120.8, 120.7, 58.6, 46.0. - HR ESI(-)-MS: Calcd. 347.1838 for C24H17BP [3] . Found. 347.1814 S3 1 Figure S1. [3][Li(THF)4], H NMR, CD3CN, 400 MHz, 298 K Li(THF)4 P B Ph 7 1 Figure S2. [3][Li(THF)4], Li{ H} NMR, CD3CN, 156 MHz, 298 K Li(THF)4 P B Ph S4 31 1 Figure S3. [3][Li(THF)4], P{ H} NMR, THF-d8, 162 MHz, 298 K Li(THF)4 P B Ph 11 1 Figure S4. [3][Li(THF)4], B{ H} NMR, CD3CN, 128 MHz, 298 K Li(THF)4 P B Ph S5 13 1 Figure S5. [3][Li(THF)4], C{ H} NMR, THF-d8, 100 MHz, 298 K Li(THF)4 P B Ph S6 Li(THF)4 NEt4 P P [NEt4]Br B MeOH, r.t. B Ph Ph [3][NEt4] (97%) Route A: Tetraethylammonium 9-phosphatriptycene-10-phenylborate ([3][NEt4]): To a stirring MeOH (1 mL) solution of [3][Li(THF)4] (13 mg, 20.4 µmol) was added [NEt4]Br (4.3 mg, 20.4 µmol) in MeOH (1 mL) at room temperature. Within minutes, a white precipitate formed. After 30 min, the resulting white solid was collected by filtration and washed with MeOH (4 × 1 mL). The solids were dried in-vacuo providing [3][NEt4] (12 mg, 97%). The filtrate was concentrated and stored at –35 ºC to afford [3][NEt4] as colorless crystals. NEt4 tBuLi (5.5 equiv.), -78 oC, 2 h P Br Br o [NEt ]Br PhBCl2, -78 C, 1 h 4 P -78 oC to 0 oC, 12 h MeOH, r.t., 12 h B 0 oC to r.t., 12 h Br 5:1 Et2O/THF Ph [3][NEt4] (30%) Route B: Tetraethylammonium 9-phosphatriptycene-10-phenylborate ([3][NEt4]): An oven-dried 1000 mL three-neck flask was fitted with a flow control two-way-glass adapter, rubber septum, and a 100 mL liquid addition funnel capped with a rubber septum. Under an N2 atmosphere, the flask was charged with tris(2- 1 bromophenyl)phosphine (2.044 g, 4.096 mmol), a mixture of Et2O (600 mL):THF (200 mL), and a magnetic stir bar. The addition funnel was charged with 1.7 M tBuLi in pentane (1.7 M, 13.3 mL, 22.5 mmol) and the three-neck flask was cooled in a acetone/dry ice slush bath (~ –78 ºC) with vigorous stirring for ~ 10 min. Addition of tBuLi was commenced drop wise over 25 min. The addition funnel was washed with Et2O (10 mL) and subsequently added over 3 min, causing a color change to dark green. The reaction mixture was allowed to stir at – 78 ºC for 2 h. The addition funnel was subsequently charged with distilled PhBCl2 (0.5 mL, 4.1 mmol) diluted in Et2O (52 mL). This solution was added drop wise over 1.25 h to the vigorously stirred reaction mixture, causing a color change to orange. After the mixture was stirred for an additional 6 h, the mixture was allowed to warm gradually to 0 ºC overnight (~ 12 h). The next morning, the mixture was allowed to warm gradually to room temperature. After 12 S7 h, the solution was light yellow with ample white precipitate. Solvent was removed in- vacuo and the crude mixture of [3][Li(THF)4] was dissolved in MeOH (30 mL) and stirred for 2 min after which [NEt4]Br (857.0 mg, 4.096 mmol) was added at room temperature. After the addition was complete, the mixture was stirred for an additional 12 h. Solvent was removed in-vacuo and the residue was washed with MeOH and filtered to give ammonium salt [3][NEt4] (734 mg, 30%) as a white solid. 1 3 H NMR (CD3CN, 400 MHz, 298 K): δ = 8.03 (br, 2H; o-Ph), 7.58 (d, JH,H = 7.2 Hz, 3 3 3H), 7.38-7.42 (m, 5H), 7.21 (t, JH,H = 7.2 Hz, 1H; p-Ph), 6.86 (t, JH,H = 7.2 Hz, 3H), 3 3 3 6.77 (t, JH,H = 7.2 Hz, 3H), 3.06 (q, JH,H = 7.2 Hz, CH2(NEt4), 8H), 1.14 (t, JH,H = 7.2 Hz, CH3(NEt4), 12H). 31 1 3 P{ H} NMR (CD3CN, 162 MHz, 298 K): δ = –46.8 (d, JP,B = 4.0 Hz). 11 1 3 B{ H} NMR (CD3CN, 128 MHz, 298 K): δ= –8.2. (d, JP,B = 4.0 Hz). 13 C NMR (CD3CN, 100 MHz, 298 K): δ = 146.7, 137.2, 132.8, 132.3, 131.7, 127.5, 126.1, 123.9, 122.2, 122.1, 53.0, 7.6. - HR ESI(-)-MS: Calcd. 347.1838 for C24H17BP [3] . Found. 347.2051 S8 1 Figure S6. [3][NEt4], H NMR, CD3CN, 400 MHz, 298 K NEt4 P B Ph 31 1 Figure S7.