ACCEPTED MANUSCRIPT
Synthesis of 1-tert-butyl-3-[phenyl(pyridin-2-yl)methyl]-1H-imidazolium chloride, 4c
Brown solid, 8.24 g, 54.0 %. 1H NMR (300 MHz, CDCl3): δ = 1.70 (s, 9 H, CCH3), 7.27-7.37 (m, 5 H, arom.),
7.50-7.55 (m, 2H, arom.), 7.69-7.75 (m, 1 H, arom.), 7.81-7.83 (m, 1 H, arom.), 8.14 (s, 1 H, arom.), 8.59 (ddd,
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1 H, JH,H = 0.9 Hz, JH,H = 1.8 Hz, JH,H = 4.8 Hz) and 11.19 (s, 1 H, carbenic proton) ppm. C NMR (75 MHz,
CDCl3): δ = 30.05 (CCH3), 60.13 (NCCH3), 65.26 (NCPh), 117.97, 122.50, 123.60, 124.87, 128.91, 129.07,
136.53 and 136.96, 137.55, 149.30 and 155.44 ppm. MS (ESI) m/z: [M-Cl]+ calcd. for C19H22N3 292.1814,
found 292.3259.
Synthesis of pyridine functionalized Pt NHC complexes (±)-5
To a solution of pyridine-functionalized NHC precursors 4a, 4b, 4c (1 mol equiv.) in 30 mL of CH2Cl2, Ag2O
(0.5 mol equiv.) was added in the dark. The reaction mixture was stirred at room temperature for 12 hours and
was filtered through a short plug of celite. The Pt(cod)Cl2 (1 mol equiv.) was added to the orange filtrate in the
dark. The reaction mixture was then allowed to stir at room temperature for two weeks and was filtered through
celite. The filtrate was then reduced in vacuo to yield the racemic Pt NHC complexes (±)-5.
Synthesis of racemic Pt NHC complex (±)-5a
Off white solid 0.760 g, 35.0 %. M.p. = 236 – 238 °C (decomposed). 1H NMR (300 MHz, DMSO-d6): δ = 3.90
(s, 3 H, CH3), 7.05 (s, 1 H, arom.), 7.26-7.45 (m, 6 H, arom.), 7.54-7.60 (m, 1 H, arom.), 7.75 (d, 1 H, JH,H = 2.1
Hz, arom.), 7.97-7.99 (m, 1 H, arom.), 8.20-8.26 (m, 1 H, arom.) and 9.31 (dd, 1 H, JH,H = 1.5 Hz, JH,H = 6.0 Hz,
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arom.) ppm. C NMR (75 MHz, DMSO-d6): δ = 37.60 (CH3), 66.95 (NCPh), 122.09, 123.90, 126.32, 127.22,
128.49, 129.07, 129.48, 138.15, 139.84, 140.29, 154.57, 155.57 ppm. MS (ESI) m/z: [M]+ calcd. for
C16H15Cl2N3Pt 514.0291, found 514.0169. Light yellow crystals were obtained from slow diffusion of diethyl
ether into a methanol/DMSO solution of (±)-5a.
Synthesis of racemic Pt NHC complex (±)-5b
Orange solid 1.37 g, 44.5 %. M.p. = 241 – 243 °C (decomposed). 1H NMR (300 MHz, DMSO-d6): δ = 7.42 (s, 1
H. arom.), 7.47-7.51 (m, 4 H, arom.), 7.55-7.61 (m, 4 H, arom.), 7.72-7.74 (m, 1 H, arom.), 7.86-7.92 (m, 3 H,
arom.), 8.14-8.19 (m, 2 H, arom.), 8.30-8.31 (m, 1 H, arom), 9.41 (dd, 1 H, JH,H = 1.2 Hz, 5.7 Hz, arom.) ppm.
13C NMR (75 MHz, DMSO-d6): δ = 67.53 (NCPh), 121.83, 125.37, 127.03, 127.45, 128.89, 129.12, 129.49,
129.82, 130.32, 139.04, 139.37, 140.76, 155.07 and 155.58 ppm. MS (ESI) m/z: [MH-Cl]+ calcd. for
C21H18ClN3Pt 542.0837, found 542.0283.
Synthesis of racemic Pt NHC complex (±)-5c
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Brown solid, 1.71g, 51.0%. M.p. = 227 – 228 °C (decomposed). H NMR (300 MHz, DMSO-d6): δ = 1.61 (s, 9
H, CCH3), 7.21 (s, 1 H, arom.), 7.34-7.48 (m, 6 H, arom.), 7.77-7.90 (m, 2 H, arom.), 7.94-7.96 (m, 1 H, arom.),
8.07 (t, 1 H, JH,H = 2.1 Hz, arom.) and 8.64-8.66 (m, 1 H, arom.) ppm. 13C NMR (75 MHz, DMSO-d6): δ =
30.88 (CCH3), 60.38 (NCCH3), 66.45 (NCPh), 120.90, 123.02, 123.89, 124.34, 128.37, 128.96, 129.56, 135.42,