How to build and race a fast nanocar Synthesis Information Grant Simpson, Victor Garcia-Lopez, Phillip Petemeier, Leonhard Grill*, and James M. Tour*, Department of Physical Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria Departments of Chemistry and Materials Science and NanoEngineering, and the Smalley- Curl Institute and NanoCarbon Center, Rice University, Houston, Texas 77005, United States Scheme 1. Synthesis of Dipolar Racer (1). 1
Experimental General synthetic methods 1 H NMR and 13 C NMR spectra were recorded at 600 and 150 MHz, respectively. Chemical shifts (δ) are reported in ppm from tetramethylsilane (TMS). All glassware was oven-dried overnight prior to use. Reagent grade tetrahydrofuran (THF) was distilled from sodium benzophenoneketyl under N 2 atmosphere. Triethylamine (Et 3 N), and dichloromethane (CH 2 Cl 2 ) were distilled from calcium hydride (CaH 2 ) under N 2 atmosphere. THF and Et 3 N were degassed with a stream of argon for 15 min before being used in the Sonogashira coupling reactions. Palladium-catalyzed reactions were carried out under argon atmosphere. All other chemicals were purchased from commercial suppliers and used without further purification. Flash column chromatography was performed using 230-400 mesh silica gel from EM Science. Thin layer chromatography (TLC) was performed using glass plates precoated with silica gel 40 F 254 0.25 mm layer thickness purchased from EM Science. Reported procedures were followed for the synthesis of compounds 3-4 (ref. S1) and 5 (ref. S2). Dipolar Racer 1. To a solution of 7 (25 mg, 0.055 mmol) in THF (10 ml) was added sodium borohydride powder (NaBH4, 29 mg, 0.77 mmol) and the mixture was cooled to -5 C. Then a mixture of formaldehyde (CH2O, 0.5 ml) and sulfuric acid (H2SO4, 2.0 ml) were added dropwise maintaining the same temperature. After the addition was complete, the mixture was stirred at room temperature for 20 min. The reaction was quenched with 15 ml of an ethanol/water (1:1 v/v) mixture and the organic phase was extracted with diethyl ether (Et2O, 3 X 20 ml). The organic extract was dried over anhydrous magnesium sulfate (MgSO4) and the solvent was removed in vacuo. The residue was purified by column chromatography (silica 2
gel, 3% EtOAc in hexanes) to provide 1 as pale yellow solid (22 mg, 85%). 1 H NMR (600 MHz, CDCl3) δ 8.08 (s, 1H), 6.75 (s, 1H), 3.10 (s, 6H), 2.00 (br s, 12H), 1.96-1.94 (m, 6H), 1.75-1.70 (m, 12 H). 13 C NMR (150 MHz, CDCl3) δ 156.26, 140.42. 132.45, 120.47, 120.07, 112.08, 106.56, 105.59, 77.79, 76.70, 42.69, 42.63, 42.47, 36.50, 36.48, 30.82, 30.66, 28.06, 28.05. HRMS (ESI) m/z calcd. for [M+H] + C32H38N2O2 483.3006, found 483.2998. Compound 6. An oven dried 10 ml screw-cap tube equipped with a stir bar was charged under argon flow with compound 4 (300 mg, 0.89 mmol), ethynyladamantane 5 (356 mg, 2.22 mmol), Pd2(dba)3 CHCl3 (92 mg, 0.089 mmol), PPh3 (117 mg, 0.45 mmol), and CuI (34 mg, 0.178 mmol). Freshly distilled and degassed THF (3.75 ml) and NEt 3 (1.25mL) were added, the screw-cap tube was sealed, and the reaction mixture was stirred at 70 C for 12 h. After cooling to rt, the reaction was quenched with saturated NH4Cl(aq) (20 ml) and extracted with CH2Cl2 (2 X 30 ml). The organic phase was washed with water (30 ml), dried over anhydrous MgSO4, filtered, and the filtrate was concentrated under vacuum. The crude product was purified by column chromatography (silica gel, 5-10% EtOAc in hexanes) to provide 6 as a yellow solid (331 mg, 85%). 1 H NMR (600 MHz, CDCl3) δ 8.60 (s, 1H), 8.04 (br s, 1H), 8.03 (s, 1H), 2.25 (s, 3H), 2.06-2.03 (m, 3H), 2.0-1.97 (m, 15 H), 1.77-1.74 (m, 6H), 1.73-1.71 (m, 6H). 13 C NMR (150 MHz, CDCl3) δ 168.27, 144.50, 141.91, 127.79, 123.26, 120.50, 111.73, 109.13, 108.46, 75.91, 73.14, 42.80, 42.30, 36.45, 36.26, 30.84, 30.79, 28.00, 27.90, 25.12. HRMS (ESI) m/z calcd. for [M+H] + C32H36N2O3 calc. 497.2799, found 497.2790. Compound 7. In a 50 ml round-bottom flask, precursor 6 (200 mg, 0.40 mmol) was dissolved in CH2Cl2 (10 ml). Methanol (10 ml) and K2CO3 (553 mg, 4.0 mmol) were added and the mixture was stirred at room temperature for 4 h. The solvents were evaporated under vacuum and the product was purified by column chromatography (silica gel, 3% EtOAc in hexanes) to 3
provide 7 as a yellow solid (173 mg, 95%). 1 H NMR (600 MHz CDCl3) δ 8.06 (s, 1H), 6.73 (s, 1H), 4.66 (br s, 2H), 2.01-1.95 (m, 18H), 1.73-1.71 (m, 12H). 13 C NMR (150 MHz, CDCl3) δ 150.90, 140.03, 129.77, 120.91, 117.88, 107.77, 106.72, 106.69, 76.41, 73.81, 42.98, 42.46, 36.48, 36.39, 30.79, 30.67, 28.05, 28.03 HRMS (ESI) m/z calcd. for [M+H] + C30H34N2O2 [M+H] + 455.2693, found 455.2687. Supplementary References S1. Tour, J. M., Rawlett, A. M., Kozaki, M., Yao, Y., Jagessar, R. C., Dirk, S. M., Price, D. W., Reed, M. A., Zhou, C.-W., Chen, J., Wang, W., Campbell, I. Synthesis and preliminary testing of molecular wires and devices. Chem. Eur. J. 7, 5118 5134 (2001). S2. Chu, P.-L., Wang, L.-Y., Khatua, S., Kolomeisky, A. B., Link, S., Tour, J. M. Synthesis and single-molecule imaging of highly mobile adamantane-wheeled nanocars. ACS Nano 7, 35-41 (2013). NMR Spectra of New Compounds: Supplementary Figure 1. 1 H NMR of 1. 4
Supplementary Figure 2. 13 C NMR of 1. Supplementary Figure 3. 1 H NMR of 6. 5
Supplementary Figure 4. 13 C NMR of 6. Supplementary Figure 5. 1 H NMR of 7. 6
Supplementary Figure 6. 13 C NMR of 7. 7