Supporting Information. for

Supporting Information for A general synthetic route to [Cu(X)(NHC)] (NHC = N- heterocyclic carbene, X =Cl, Br, I) complexes Orlando Santoro, Alba Collado, Alexandra M. Z. Slawin, Steven P. Nolan and Catherine S. J. Cazin* EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK. cc111@st-andrews.ac.uk S1

Table of Contents General considerations... S3 Synthesis of the [Cu(X)(NHC)] complexes... S3 Screening of the reaction conditions... S3 General Procedure... S3 Small scale:... S3 Large scale... S4 Synthesis of [Cu(Cl)(IPr)] (2a)... S4 Synthesis of [Cu(Cl)(SIPr)] (2b)... S5 Synthesis of [Cu(Cl)(IMes)] (2c)... S5 Synthesis of [Cu(Cl)(SIMes)] (2d)... S6 Synthesis of [Cu(Cl)(IPr*)] (2e)... S6 Synthesis of [Cu(Cl)(I t Bu)] (2f)... S7 Synthesis of [Cu(Cl)(ICy)] (2g)... S7 Synthesis of [Cu(Cl)(SICy)] (2h)... S8 Synthesis of [Cu(Br)(IPr)] (2i)... S9 Synthesis of [Cu(I)(IPr)] (2j)... S9 Synthesis of the [(NHC)H][CuXY] salts (3a-3k)... S10 General Procedure... S10 Synthesis of [IPrH][CuCl 2 ] (3a)... S10 Synthesis of [SIPrH][CuCl 2 ] (3b)... S11 Synthesis of [IMesH][CuCl 2 ] (3c)... S12 Synthesis of [SIMesH][CuCl 2 ] (3d)... S12 Synthesis of [ICyH][CuCl 2 ] (3g)... S13 Synthesis of [IPrH][CuClBr] (3i)... S14 Synthesis of [IPrH][CuClI] (3j)... S14 Synthesis of [IPrH][CuBrI] (3k)... S15 1 H and 13 C-{1H} NMR spectra... S16 Crystal data and Structure refinement... S34 S2

General considerations All reactions were carried under air and technical grade solvent were used unless otherwise stated. K 2 CO 3 and KHCO 3 were used as received without further purification. 1 H, and 13 C- { 1 H} Nuclear Magnetic Resonance (NMR) spectra were recorded on a Bruker ADVANCE 300 MHz and Bruker ADVANCE 400 MHz spectrometer using the residual solvent peak as reference (CHCl 3 : δ H = 7.26 ppm, δ C = 77.16 ppm, CH 2 Cl 2 : δ H = 5.32 ppm, δ C = 53.84 ppm) at 298K. Elemental analyses were performed at London Metropolitan University 166-220, Holloway Road, London, N7 8DB. Synthesis of the [Cu(X)(NHC)] complexes Screening of the reaction conditions Entry Base (equiv.) Solvent T ( C) Time (h) Conversion (%) a 1 K 2 CO 3 (1.5) acetone rt 24 75 2 K 2 CO 3 (2.0) acetone rt 24 84 3 K 2 CO 3 (1.0) acetone 60 24 80 4 K 2 CO 3 (2.0) acetone 60 24 >99 5 K 2 CO 3 (10) acetone 60 1 >99 6 KHCO 3 (2.0) acetone 60 24 95 7 K 2 CO 3 (2.0) THF 60 24 80 a Conversion determined by 1 H NMR analysis. General Procedure Small scale: A vial was charged with NHC. HCl (1.0 equiv.), CuX (1.0 equiv.) and K 2 CO 3 (2.0 equiv.). The mixture was dissolved in acetone (1.0 ml) and stirred at 60 C for 24 hours. The solution was then filtered through silica which was washed with dichloromethane (3 x 1.0 ml). The solvent was concentrated under vacuum and pentane (3.0 ml) was added thereby precipitating the desired product that was washed with further portions of pentane (3 x 1.0 ml) and dried under vacuum. S3

Large scale: a round bottom flask equipped with a condenser was charged with IPr. HCl (1.0 equiv.), CuX (X = Cl, Br, I, 1.0 equiv.) and K 2 CO 3 (3.0 equiv.). The mixture was dissolved in acetone and stirred for 8-15 h at 60 C. The same work-up as the small scale procedure was carried out. Synthesis of [Cu(Cl)(IPr)] (2a) Reaction between IPr. HCl (1a) (100 mg, 0.23 mmol), CuCl (23 mg, 0.23 mmol) and K 2 CO 3 (66 mg, 0.46 mmol) led to the isolation of 2a as a white solid in 92% isolated yield (103 mg, 0.21 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 1.23 (d, 3 J H-H = 6.9 Hz, 12H, CH-CH 3 ), 1.30 (d, 3 J H- H = 6.9 Hz, 12H, CH-CH 3 ), 2.56 (sept, 3 J H-H = 6.9 Hz, 4H, CH-CH 3 ), 7.13 (s, 2H, H 4 and H 5 ), 7.29 (d, 3 J H-H = 7.8 Hz, 4H, CH phenyl), 7.49 (t, 3 J H-H = 7.8 Hz, 2H, CH phenyl). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 24.0 (s, CH-CH 3 ), 24.9 (s, CH-CH 3 ), 28.8 (s, CH-CH 3 ), 123.3 (s, C IV Ar), 124.3 (s, CH Ar), 130.7 (s, C 4 and C 5 ), 134.5 (s, C IV Ar), 145.7 (s, CH Ar), 180.6 (s, C 2 ). Elem. Anal. Calcd. for C 27 H 37 ClCuN 2 : C, 66.37; H, 7.63, N, 5.73. Found: C, 66.62, H, 7.31, N, 5.84 S4

Synthesis of [Cu(Cl)(SIPr)] (2b) Reaction between SIPr. HCl (1b) (100 mg, 0.23 mmol), CuCl (23 mg, 0.23 mmol) and K 2 CO 3 (66 mg, 0.46 mmol) led to the isolation of 2b as a white solid in 84% isolated yield (94 mg, 0.19 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 1.34 (d, 3 J H-H = 7.0 Hz, 12H, CH-CH 3 ), 1.36 (d, 3 J H- H = 7.0 Hz, 12H, CH-CH 3 ), 3.06 (sept, 3 J H-H = 6.9 Hz, 4H, CH-CH 3 ), 4.01 (s, 4H, H 4 and H 5 ), 7.24 (d, 3 J H-H = 7.8 Hz, 4H, CH phenyl), 7.39 (t, 3 J H-H = 7.8 Hz, 2H, CH phenyl). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 24.0 (s, CH-CH 3 ), 25.6 (s, CH-CH 3 ), 29.0 (s, CH-CH 3 ), 53.8 (s, C 4 and C 5 ), 124.6 (s, CH Ar), 130.0 (s, C IV CH Ar), 134.5 (s, C IV Ar), 146.7 (s, CH Ar), 203.1 (s, C 2 ). Synthesis of [Cu(Cl)(IMes)] (2c) Reaction between IMes. HCl (1c) (100 mg, 0.29 mmol), CuCl (29 mg, 0.29 mmol) and K 2 CO 3 (80 mg, 0.58 mmol) led to the isolation of 2c as a white solid in 76% isolated yield (89 mg, 0.22 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 2.10 (s, 12H, CH 3 ), 2.34 (s, 6H, CH 3 ), 6.99 (s, 4H, CH phenyl), 7.05 (s, 2H, H 4 and H 5 ). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 17.9 (s, CH 3 ), 21.2 (s, CH 3 ), 122.4 (s, C IV Ar), 129.6 (s, CH Ar), 134.7 (s, C 4 and C 5 ), 135.2 (s, C IV Ar), 139.6 (s, C IV Ar), 179.1 (s, C 2 ). S5

Synthesis of [Cu(Cl)(SIMes)] (2d) Reaction between SIMes. HCl (1d) (100 mg, 0.29 mmol), CuCl (29 mg, 0.29 mmol) and K 2 CO 3 (80 mg, 0.58 mmol) led to the isolation of 2d as a white solid in 94% isolated yield (110 mg, 0.27 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 2.29 (s, 6H, CH 3 ), 2.30 (s, 12H, CH 3 ), 3.93 (s, 2H, H 4 and H 5 ), 6.93 (s, 4H, CH phenyl). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 18.1 (s, CH 3 ), 21.1 (s, CH 3 ), 51.0 (s, C 4 and C 5 ), 129.8 (s, CH Ar), 135.1 (s, C IV Ar), 135.5 (s, C IV Ar), 138.6 (s, C IV Ar), 202.5 (s, C 2 ). Synthesis of [Cu(Cl)(IPr*)] (2e) Reaction between IPr*. HCl (1e) (100 mg, 0.10 mmol), CuCl (9.90 mg, 0.10 mmol) and K 2 CO 3 (27.6 mg, 0.20 mmol) led to the isolation of 2e as a white solid in 70% isolated yield (71 mg, 0.07 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 2.23 (s, 6H, CH 3 ), 5.21 (s, 4H, CHPh 2 ), 5.83 (s, 2H, H 4 and H 5 ), 6.86 (s, 4H, CH phenyl), 6.90-6.92 (m, 8H, CH phenyl), 7.03 (m, 8H, CH aryl), 7.15-7.21 (m, 24H, CH aryl). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 21.9 (s, CH 3 ), 51.3 (s, CHPh 2 ), 123.3 (s, C 4 and C 5 ), 126.7 (s, CH Ar), 126.8 (s, CH Ar), 128.5 (s, CH Ar), 128.7 (s, CH Ar), 129.5 (s, CH Ar), 129.7 (s, CH Ar), 130.3 (s, CH Ar), 134.3 (s, C IV Ar), 140.1 (s, C IV Ar), 141.0 (s, C IV Ar), 142.4 (s, C IV Ar), 143.2 (s, C IV Ar), 180.4 (s, C 2 ). S6

Synthesis of [Cu(Cl)(I t Bu)] (2f) Reaction (carried out under Ar atmosphere) between I t Bu. HCl (1f) (100 mg, 0.37 mmol), CuCl (36.6 mg, 0.37 mmol) and K 2 CO 3 (99.4 mg, 0.74 mmol) led to the isolation of 2f as a white solid in 55% isolated yield (47 mg, 0.21 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 1.75 (s, 18H, CH 3 ), 7.03 (s, 2H, H 4 and H 5 ). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 32.1 (s, CH 3 ), 116.7 (s, C 4 and C 5 ), 172.8 (s, C 2 ). Synthesis of [Cu(Cl)(ICy)] (2g) Reaction between ICy. HCl (1g) (100 mg, 0.37 mmol), CuCl (36.7 mg, 0.37 mmol) and K 2 CO 3 (99.4 mg, 0.74 mmol) led to the isolation of 2g as a white solid in 80% isolated yield (98 mg, 0.30 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 1.20 (m, 2H, CH 2 ), 1.40 (m, 4H, CH 2 ), 1.56-1.71 (m, 6H, CH 2 ), 1.84 (m, 4H, CH 2 ), 2.00 (m, 4H, CH 2 ), 4.24 (m, 2H, CH), 6.91 (s, 2H, H 4 and H 5 ). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 25.0 (s, CH 2 ), 25.4 (s, CH 2 ), 34.7 (s, CH 2 ), 61.1 (s, CH), 117.5 (s, C 4 and C 5 ), 173.3 (s, C 2 ). S7

Synthesis of [Cu(Cl)(SICy)] (2h) Under Ar, a vial was charged with SICy. HCl (1h) (100 mg, 0.37 mmol, 1.0 equiv.), CuCl (36.6 mg, 0.37 mmol, 1.0 equiv.) and K 2 CO 3 (99.4 mg, 0.74 mmol, 2.0 equiv.) The mixture was dissolved in dry dichloromethane (1.0 ml) and stirred at 60 C for 24 hours. The solution was then filtered through silica which was washed with dichloromethane (3 x 1 ml). Evaporation under reduced pressure of the volatiles led to the isolation of 2h as a white solid in 49% isolated yield (60 mg, 0.19 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 1.04 (m, 2H, CH 2 ), 1.29 (m, 4H, CH 2 ), 1.43 (m, 4H, CH 2 ), 1.61 (m, 2H, CH 2 ), 1.76 (m, 8H, CH 2 ), 3.45 (s, 3 J H-H = 12.0 Hz, 4H, H 4 and H 5 ), 3.77 (m, 2H, CH). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 25.2 (s, CH 2 ), 25.3 (s, CH 2 ), 31.9 (s, CH 2 ), 44.2 (s, C 4 and C 5 ), 59.6 (s, CH), 197.3 (s, C 2 ). S8

Synthesis of [Cu(Br)(IPr)] (2i) Reaction between IPr. HCl (1a) (100 mg, 0.23 mmol), CuBr (33 mg, 0.23 mmol) and K 2 CO 3 (66 mg, 0.46 mmol) led to the isolation of 2i as a white solid in 88% isolated yield (106 mg, 0.20 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 1.22 (d, 3 J H-H = 6.9 Hz, 12H, CH-CH 3 ), 1.30 (d, 3 J H- H = 6.9 Hz, 12H, CH-CH 3 ), 2.56 (sept, 3 J H-H = 6.9 Hz, 4H, CH-CH 3 ), 7.14 (s, 2H, H 4 and H 5 ), 7.29 (d, 3 J H-H = 7.8 Hz, 4H, CH phenyl), 7.48 (t, 3 J H-H = 7.8 Hz, 2H, CH phenyl). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 24.0 (s, CH-CH 3 ), 24.9 (s, CH-CH 3 ), 28.8 (s,ch-ch 3 ), 123.2 (s, C IV Ar), 124.3 (s, CH Ar), 130.6 (s, C 4 and C 5 ), 134.4 (s, C IV Ar), 145.6 (s, CH Ar), 181.2 (s, C 2 ). Synthesis of [Cu(I)(IPr)] (2j) Reaction between IPr. HCl (1a) (100 mg, 0.23 mmol), CuI (44 mg, 0.23 mmol) and K 2 CO 3 (66 mg, 0.46 mmol) led to the isolation of 2j as a white solid in 77% isolated yield (104 mg, 0.18 mmol). 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 1.23 (d, 3 J H-H = 6.9 Hz, 12H, CH-CH 3 ), 1.30 (d, 3 J H- H = 6.9 Hz, 12H, CH-CH 3 ), 2.57 (sept, 3 J H-H = 6.9 Hz, 4H, CH-CH 3 ), 7.14 (s, 2H, H 4 and H 5 ), 7.30 (d, 3 J H-H = 7.8 Hz, 4H, CH phenyl), 7.49 (t, 3 J H-H = 7.8 Hz, 2H, CH phenyl). S9

13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 24.0 (s, CH-CH 3 ), 25.0 (s, CH-CH 3 ), 28.8 (s, CH-CH 3 ), 123.2 (s, C IV Ar), 124.3 (s, CH Ar), 130.7 (s, C 4 and C 5 ), 134.3 (s, C IV Ar), 145.7 (s, CH Ar), 183.0 (s, C 2 ). Synthesis of the [(NHC)H][CuXY] salts (3a-3k) General Procedure NHC HX and CuY (X, Y = Cl, Br, I) were charged in a vial equipped with a magnetic stirring bar. The final solids mixture was dissolved in acetone (3.0 ml) and stirred for 10 minutes at room temperature. After this time the solvent was removed under reduced pressure affording the product. Synthesis of [IPrH][CuCl 2 ] (3a) Reaction between IPr HCl (1a) (300 mg, 0.70 mmol) and CuCl (69 mg, 0.70 mmol) led to the isolation of 3a as a white solid in 95% isolated yield (350 mg, 0.66 mmol). 1 H NMR (400 MHz, CD 2 Cl 2, 298 K): δ = 1.22 (d, 3 J H-H = 7.1 Hz, 12H, CH-CH 3 ), 1.28 (d, 3 J H-H = 7.1 Hz, 12H, CH-CH 3 ), 2.39 (sept, 3 J H-H = 7.1 Hz, 4H, CH-CH 3 ), 7.39 (d, 3 J H-H = 7.8 Hz, 4H, CH phenyl), 7.62 (t, 3 J H-H = 7.8 Hz, 2H, CH phenyl), 7.79 (s, 2H, H 4 and H 5 ) 10.00 (s, 1H, H 2 ). 13 C-{ 1 H} NMR (75 MHz, CD 2 Cl 2, 298 K): δ = 23.8 (s, CH-CH 3 ), 24.7 (s, CH-CH 3 ), 29.5 (s, CH-CH 3 ), 125.1 (s, CH Ar), 126.2 (s, CH Ar), 130.1 (s, C IV Ar), 136.5 (s, C 4 and C 5 ), 139.2 (s, C 2 ), 145.3 (s, C IV Ar). S10

Elem. Anal.: Calcd. for C 27 H 37 Cl 2 CuN 2 : C, 61.88; H, 7.12, N, 5.35. Found: C, 61.96, H, 7.15, N, 5.41 Synthesis of [SIPrH][CuCl 2 ] (3b) Reaction between SIPr. HCl (1b) (100 mg, 0.23 mmol), CuCl (23 mg, 0.23 mmol) led to the isolation of 3b as a white solid in 87% isolated yield (109 mg, 0.20 mmol). Crystals suitable for X-ray diffraction were grown by slow diffusion of pentane in a saturated solution of 3b in dichloromethane. 1 H NMR (400 MHz, CD 2 Cl 2, 298 K): δ = 1.26 (d, 3 J H-H = 6.9 Hz, 12H, CH-CH 3 ), 1.39 (d, 3 J H-H = 6.9 Hz, 12H, CH-CH 3 ), 3.00 (sept, 3 J H-H = 7.0 Hz, 4H, CH-CH 3 ), 4.59 (s, 4H, H 4 and H 5 ), 7.32 (d, 3 J H-H = 7.9 Hz, 4H, CH phenyl), 7.52 (t, 3 J H-H = 7.9 Hz, 2H, CH phenyl), 8.63 (s, 1H, H 2 ). 13 C-{ 1 H} NMR (75 MHz, CD 2 Cl 2, 298 K): δ = 24.1 (s, CH-CH 3 ), 25.5 (s, CH-CH 3 ), 29.6 (s, CH-CH 3 ), 54.6 (s, C 4 and C 5 ), 125.5 (s, CH Ar), 129.4 (s, C IV CH Ar), 132.1 (s, C IV Ar), 146.5 (s, CH Ar), 159.2 (s, C 2 ). Elem. Anal.: Calcd. for C 27 H 39 Cl 2 CuN 2 : C, 61.65; H, 7.47, N, 5.33. Found: C, 61.75, H, 7.57, N, 5.40 S11

Synthesis of [IMesH][CuCl 2 ] (3c) Reaction between IMes. HCl (1c) (100 mg, 0.29 mmol), CuCl (29 mg, 0.29 mmol) led to the isolation of 3c as a white solid in 95% isolated yield (112 mg, 0.28 mmol). Crystals suitable for X-ray diffraction were grown by slow diffusion of pentane in a saturated solution of 3c in dichloromethane. 1 H NMR (400 MHz, CD 2 Cl 2, 298 K): δ = 2.16 (s, 12H, CH 3 ), 2.39 (s, 6H, CH 3 ), 7.11 (s, 4H, CH phenyl), 7.65 (s, 2H, H 4 and H 5 ), 9.55 (s, 1H, H 2 ). 13 C-{ 1 H} NMR (75 MHz, CD2Cl2, 298 K): δ = 17.8 (s, CH 3 ), 21.3 (s, CH 3 ), 125.2 (s, C 4 and C 5 ), 130.3 (s, CH Ar), 130.7 (s, C IV Ar), 134.5 (s, C 2 ), 138.0 (s, C IV Ar), 142.2 (s, C IV Ar). Elem. Anal.: Calcd. for C 21 H 25 Cl 2 CuN 2 : C, 57.34; H, 5.73, N, 6.37. Found: C, 57.44, H, 5.82, N, 6.46 Synthesis of [SIMesH][CuCl 2 ] (3d) Reaction between SIMes. HCl (100 mg, 0.29 mmol), CuCl (29 mg, 0.29 mmol) led to the isolation of 3d as a white solid in 94% isolated yield (110 mg, 0.27 mmol). Crystals suitable for X-ray diffraction were grown by slow diffusion of pentane in a saturated solution of 3d in dichloromethane. 1 H NMR (400 MHz, CD 2 Cl 2, 298 K): δ = 2.33 (s, 6H, CH 3 ), 2.39 (s, 12H, CH 3 ), 4.53 (s, 4H, H 4 and H 5 ), 7.04 (s, 4H, CH phenyl), 8.47 (s, 1H, H 2 ). S12

13 C-{ 1 H} NMR (75 MHz, CD 2 Cl 2, 298 K): δ = 18.3 (s, CH 3 ), 21.2 (s, CH 3 ), 52.0 (s, C 4 and C 5 ), 130.2 (s, C IV Ar), 130.5 (s, CH Ar), 135.3 (s, C IV Ar), 141.5 (s, C IV Ar), 159.4 (s, C 2 ). Elem. Anal.: Calcd. for C 21 H 27 Cl 2 CuN 2 : C, 57.08; H, 6.16, N, 6.34. Found: C, 57.16, H, 6.08, N, 6.40 Synthesis of [ICyH][CuCl 2 ] (3g) Reaction between ICy. HCl (1g) (100 mg, 0.37 mmol), CuCl (36.7 mg, 0.37 mmol) led to the isolation of 3g as a white solid in 95% isolated yield (130 mg, 0.35 mmol). Crystals suitable for X-ray diffraction were grown by slow diffusion of pentane in a saturated solution of 3g in dichloromethane. 1 H NMR (400 MHz, CDCl 3, 298 K): δ = 1.29 (m, 2H, CH 2 ), 1.53 (m, 4H, CH 2 ), 1.69-1.76 (m, 8H, CH 2 ), 1.94 (m, 4H, CH 2 ), 2.27 (m, 4H, CH 2 ), 4.52 (m, 2H, CH), 7.30 (s, 2H, H 4 and H 5 ), 10.29 (s, 1H, H 2 ). 13 C-{ 1 H} NMR (75 MHz, CDCl 3, 298 K): δ = 24.6 (s, CH 2 ), 24.9 (s, CH 2 ), 33.6 (s, CH 2 ), 60.2 (s, CH), 120.3 (s, C 4 and C 5 ), 133.6 (s, C 2 ). Elem. Anal.: Calcd. for C 15 H 25 Cl 2 CuN 2: C, 48.98; H, 6.85, N, 7.62. Found: C, 48.97, H, 6.73, N, 7.67. S13

Synthesis of [IPrH][CuClBr] (3i) Reaction between IPr HCl (300 mg, 0.70 mmol) and CuBr (100 mg, 0.70 mmol) led to the isolation of 3i as a white solid in 93% isolated yield (339 mg, 0.65 mmol). 1 H NMR (400 MHz, CD 2 Cl 2, 298 K): δ = 1.24 (d, 3 J H-H = 7.1 Hz, 12H, CH-CH 3 ), 1.30 (d, 3 J H-H = 7.1 Hz, 12H, CH-CH 3 ), 2.40 (sept, 3 J H-H = 7.1 Hz, 4H, CH-CH 3 ), 7.41 (d, 3 J H-H = 7.8 Hz, 4H, CH phenyl), 7.65 (t, 3 J H-H = 7.8 Hz, 2H, CH phenyl), 7.80 (s, 2H, H 4 and H 5 ), 9.16 (s, 1H, H 2 ). 13 C-{ 1 H} NMR (75 MHz, CD 2 Cl 2, 298 K): δ = 24.0 (s, CH-CH 3 ), 24.8 (s, CH-CH 3 ), 29.5 (s, CH-CH 3 ), 125.3 (s, CH Ar), 126.5 (s, CH Ar), 129.7 (s, C IV Ar), 132.9 (s, C 4 and C 5 ), 138.0 (s, C 2 ),145.3 (s, C IV Ar). Elem. Anal.: Calcd. for C 27 H 37 BrClCuN 2: C, 57.04; H, 6.56, N, 4.93. Found: C, 56.91, H, 6.63, N, 5.01 Synthesis of [IPrH][CuClI] (3j) Reaction between IPr HCl (300 mg, 0.70 mmol) and CuI (130 mg, 0.70 mmol) led to the isolation of 3j as a white solid in 95% isolated yield (400 mg, 0.66 mmol). 1 H NMR (400 MHz, CD 2 Cl 2, 298 K): δ = 1.23 (d, 3 J H-H = 7.1 Hz, 12H, CH-CH 3 ), 1.30 (d, 3 J H-H = 7.1 Hz, 12H, CH-CH 3 ), 2.41 (sept, 3 J H-H = 7.1 Hz, 4H, CH-CH 3 isopropyl), 7.42 (d, 3 J H-H = 7.8 Hz, 4H, CH phenyl), 7.63 (t, 3 J H-H = 7.8 Hz, 2H, CH phenyl), 7.84 (d, 2H, H 4 and H 5 ), 9.10 (t, 1H, H 2 ). S14

13 C-{ 1 H} NMR (75 MHz, CD 2 Cl 2, 298 K): δ = 24.0 (s, CH-CH 3 ), 24.8 (s, CH-CH 3 ), 29.5 (s, CH-CH 3 ), 125.4 (s, CH Ar), 126.6 (s, CH Ar), 129.7 (s, C IV Ar), 132.9 (s, C 4 and C 5 ), 137.6 (s, C 2 ), 145.3 (s, C IV Ar). Elem. Anal.: Calcd. for C 27 H 37 ClCuIN 2: C, 52.69; H, 6.06, N, 4.55. Found: C, 52.78, H, 6.07, N, 4.61 Synthesis of [IPrH][CuBrI] (3k) Reaction between IPr HBr (300 mg, 0.70 mmol) and CuI (120 mg, 0.70 mmol) led to the isolation of 3k as a white solid in 94% isolated yield (410 mg, 0.66 mmol). 1 H NMR (400 MHz, CD 2 Cl 2, 298 K): δ = 1.24 (d, 3 J H-H = 7.1 Hz, 12H, CH-CH 3 ), 1.32 (d, 3 J H-H = 7.1 Hz, 12H, CH-CH 3 ), 2.41 (sept, 3 J H-H = 7.1 Hz, 4H, CH-CH 3 ), 7.44 (d, 3 J H-H = 7.8 Hz, 4H, CH phenyl), 7.67 (t, 3 J H-H = 7.8 Hz, 2H, CH phenyl), 7.83 (s, 2H, H 4 and H 5 ), 8.87 (s, 1H, H 2 ). 13 C-{ 1 H} NMR (75 MHz, CD 2 Cl 2, 298 K): δ = 24.0 (s, CH-CH 3 ), 24.8 (s, CH-CH 3 ), 29.5 (s, CH-CH 3 ), 125.3 (s, CH Ar), 126.7 (s, CH Ar), 129.7 (s, C IV Ar), 132.9 (s, C 4 and C 5 ), 137.4 (s, C 2,145.3 (s, C IV Ar). Elem. Anal.: Calcd. for C 27 H 37 BrCuIN 2: C, 49.14; H, 5.65, N, 4.24. Found: C, 49.04, H, 5.59, N, 4.27 S15

1 H and 13 C-{1H} NMR spectra [Cu(Cl)(IPr)] 2a, 1 H NMR, CDCl 3, 298K and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.51 7.49 7.47 7.30 7.28 7.26 7.13 2.58 2.56 2.55 1.31 1.30 1.23 1.21 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 ppm 180.6 145.7 134.5 130.7 124.3 123.9 123.3 77.2 28.8 24.9 24.0 2.00 3.99 1.93 4.11 12.00 11.98 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 ppm S16

[Cu(Cl)(SIPr)] 2b, 1 H NMR, CDCl 3, 298K and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.41 7.39 7.37 7.26 7.25 7.23 4.01 3.10 3.08 3.06 3.04 3.03 1.37 1.35 1.35 1.33 9 8 7 6 5 4 3 2 1 0 ppm 203.1 146.7 134.5 130.0 124.7 77.2 53.8 29.0 25.6 24.0 1.95 3.81 3.74 4.00 11.64 11.16 220 200 180 160 140 120 100 80 60 40 20 ppm S17

[Cu(Cl)(IMes)] 2c, 1 H NMR, CDCl 3, 298K and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.26 7.05 6.99 2.34 2.10 9 8 7 6 5 4 3 2 1 0 ppm 179.1 139.6 135.2 134.7 129.6 122.4 77.2 21.2 17.9 2.07 4.16 6.00 12.17 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 ppm S18

[Cu(Cl)(SIMes)] 2d, 1 H NMR, CDCl 3, 298K and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.26 6.93 3.93 2.30 2.29 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 ppm 202.5 138.6 135.5 135.1 129.8 77.2 51.0 21.1 18.1 4.01 4.00 7.82 10.46 220 200 180 160 140 120 100 80 60 40 20 0 ppm S19

[Cu(Cl)(IPr*)] 2e, 1 H NMR, CDCl 3, 298K and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.26 7.21 7.20 7.19 7.19 7.18 7.18 7.17 7.15 7.04 7.02 6.92 6.91 6.90 6.90 6.86 5.83 5.21 2.23 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 ppm 180.4 143.2 142.4 141.0 140.1 134.3 130.3 129.7 129.5 128.7 128.5 126.8 126.7 123.3 77.2 51.3 21.9 24.17 8.47 8.21 4.38 1.99 4.04 6.00 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 ppm S20

[Cu(Cl)(I t Bu)] 2f, 1 H NMR, CDCl 3, 298K and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.26 7.03 1.75 8 7 6 5 4 3 2 1 0 ppm 172.8 116.7 77.2 32.1 2.00 18.50 200 180 160 140 120 100 80 60 40 20 0 ppm S21

[Cu(Cl)(ICy)] 2g, 1 H NMR, CDCl 3, 298K and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.26 6.91 4.28 4.24 4.20 2.04 2.00 1.86 1.82 1.71 1.68 1.65 1.60 1.56 1.46 1.42 1.37 1.33 1.24 1.20 1.16 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 ppm 173.3 117.5 77.2 61.1 34.7 25.4 25.0 1.90 2.00 4.09 4.27 6.43 4.32 2.31 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 ppm S22

[Cu(Cl)(SICy)] 2h, 1 H NMR, CDCl 3, 298K and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.26 3.80 3.77 3.77 3.74 3.45 1.76 1.75 1.61 1.59 1.45 1.41 1.31 1.29 1.28 1.07 1.05 1.02 1.00 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 ppm 197.3 77.2 59.6 44.2 31.9 25.3 25.2 2.00 3.93 8.07 2.09 4.11 4.16 2.05 220 200 180 160 140 120 100 80 60 40 20 0 ppm S23

[Cu(Br)(IPr)] 2i, 1 H NMR, CDCl 3, 298K.and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.50 7.48 7.46 7.30 7.28 7.26 7.14 2.58 2.56 2.54 1.31 1.29 1.23 1.21 8 7 6 5 4 3 2 1 0 ppm 181.2 145.6 134.4 130.6 124.3 123.2 77.2 28.8 24.9 24.0 2.09 4.09 1.79 4.16 12.00 12.03 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 ppm S24

[Cu(I)(IPr)] 2j, 1 H NMR, CDCl 3, 298K.and 13 C-{ 1 H} NMR, CDCl 3, 298 K 7.51 7.49 7.47 7.31 7.29 7.26 7.14 2.58 2.57 2.55 1.31 1.30 1.24 1.22 9 8 7 6 5 4 3 2 1 0 ppm 183.0 145.7 134.3 130.7 124.3 123.2 77.2 28.8 25.0 24.0 1.92 3.83 1.89 3.98 12.00 11.85 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 ppm S25

[IPrH][CuCl 2 ] 3a, 1 H NMR, CD 2 Cl 2, 298K.and 13 C-{ 1 H} NMR, CD 2 Cl 2, 298 K 10.00 10.00 10.00 7.79 7.79 7.64 7.62 7.60 7.40 7.38 7.34 5.32 2.41 2.39 2.38 1.28 1.27 1.22 1.21 11 10 9 8 7 6 5 4 3 2 1 ppm 145.3 139.2 132.6 126.2 125.1 53.8 29.5 24.7 23.8 0.87 1.83 1.91 3.87 4.03 12.00 11.52 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 ppm S26

[SIPrH][CuCl 2 ] 3b, 1 H NMR, CD 2 Cl 2, 298K.and 13 C-{ 1 H} NMR, CD 2 Cl 2, 298 K 8.63 7.55 7.52 7.49 7.34 7.31 5.32 4.59 3.02 3.00 2.97 1.40 1.38 1.27 1.25 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 ppm 159.2 146.5 132.1 129.4 125.5 54.6 53.8 29.6 25.5 24.1 1.00 1.88 3.86 3.81 4.00 11.82 11.72 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 ppm S27

[IMesH][CuCl 2 ] 3c, 1 H NMR, CD 2 Cl 2, 298K.and 13 C-{ 1 H} NMR, CD 2 Cl 2, 298 K 9.55 7.65 7.11 5.32 2.39 2.16 10 9 8 7 6 5 4 3 2 ppm 142.2 138.0 134.5 130.7 130.3 125.2 53.8 21.3 17.8 0.91 1.93 4.07 6.00 11.76 150 140 130 120 110 100 90 80 70 60 50 40 30 20 ppm S28

[SIMesH][CuCl 2 ] 3d, 1 H NMR, CD 2 Cl 2, 298K.and 13 C-{ 1 H} NMR, CD 2 Cl 2, 298 K 8.47 7.04 5.32 4.53 2.39 2.33 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 ppm 159.4 141.5 135.3 130.5 130.2 53.8 52.0 21.2 18.3 0.98 4.12 4.00 6.30 12.03 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 ppm S29

[ICyH][CuCl 2 ] 3g, 1 H NMR, CDCl 3, 298K.and 13 C-{ 1 H} NMR, CDCl 3, 298 K 10.29 7.30 7.26 4.52 2.28 2.25 1.96 1.92 1.76 1.68 1.54 1.51 1.30 1.27 11 10 9 8 7 6 5 4 3 2 1 ppm 133.6 120.3 77.2 60.2 33.6 24.9 24.6 0.98 1.97 2.00 4.04 4.13 7.83 4.26 2.21 130 120 110 100 90 80 70 60 50 40 30 20 ppm S30

[IPrH][CuClBr] 3i, 1 H NMR, CD 2 Cl 2, 298K.and 13 C-{ 1 H} NMR, CD 2 Cl 2, 298 K 9.16 7.80 7.67 7.65 7.63 7.43 7.41 5.32 2.42 2.40 2.39 1.31 1.30 1.25 1.23 9 8 7 6 5 4 3 2 1 ppm 145.3 138.0 132.9 129.7 126.5 125.3 53.8 29.5 24.8 24.0 0.97 1.99 2.04 4.04 4.02 12.00 11.52 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 ppm S31

[IPrH][CuClI] 3j, 1 H NMR, CD 2 Cl 2, 298K.and 13 C-{ 1 H} NMR, CD 2 Cl 2, 298 K 9.10 9.10 9.10 7.84 7.84 7.67 7.65 7.63 5.32 2.46 2.44 2.43 2.39 2.37 2.36 1.31 1.29 1.24 9 8 7 6 5 4 3 2 ppm 145.3 137.6 132.9 129.7 126.6 125.4 53.8 29.5 24.8 24.0 0.97 1.73 1.97 3.73 4.14 12.00 11.65 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 ppm S32

[IPrH][CuBrI] 3k, 1 H NMR, CD 2 Cl 2, 298K.and 13 C-{ 1 H} NMR, CD 2 Cl 2, 298 K 8.88 8.87 7.83 7.83 7.69 7.67 7.65 7.45 7.43 5.32 2.43 2.41 2.39 1.33 1.31 1.25 1.23 9 8 7 6 5 4 3 2 1 0 ppm 145.3 137.4 132.9 129.7 126.7 125.3 53.8 29.5 24.8 24.0 0.94 1.96 1.97 3.97 4.10 12.00 12.04 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 ppm S33

Crystal data and Structure refinement [SIPrH][CuCl 2 ]/CCDC-940850 (3b) [IMesH][CuCl 2 ]/CCDC-940851 (3c) S34

[SIMes][CuCl 2 ]/CCDC-940852 (3d) [SIMes][CuCl 2 ]/CCDC-940853 (3g) S35

CCDC/940850 3b CCDC/940851 3c CCDC/940852 3d CCDC-940853 3g Empirical formula C 27 H 39 Cl 2 CuN 2 C 21 H 25 Cl 2 CuN 2 C 21 H 27 Cl 2 CuN 2 C 15 H 25 Cl 2 CuN 2 Formula weight 526.07 439.89 441.91 367.83 Temperature (K) 93 93 93 93 Wavelength (Å) 0.71075 0.71075 0.71075 0.71075 Crystal system orthorhombic monoclinic monoclinic monoclinic Space group Pca2 1 P2 1 /c P2 1 /c C2/c a (Å) b (Å) c (Å) 14.746(4) 19.910(4) 19.522(4) 8.572(4) 15.885 (7) 15.852 (6) 8.388(3) 16.503(5) 15.847(5) 23.087(12) 9.877(4) c 16.619(8) α, β, γ ( ) 90, 90, 90 90, 100.145(13), 90 90, 100.157(7), 90 90, 114.446(11), 90 Volume (Å) 3 5731(2) 2124.9(15) 2159.2(11) 3450(3) Z 8 4 4 8 Density calculated (g/cm 3 ) 1.219 1.375 1.359 1.416 Absorption coefficient (mm -1 ) 0.96 1.286 1.266 1.568 F(000) 2224.00 912.00 920.00 1536.00 Crystal size (mm 3 ) 0.20 x 0.20 x 0.08 0.10 0.10 0.05 0.12 0.12 0.12 0.12 0.12 0.12 Theta range for data collection ( ) 2.0 to 23.5 1.23 to 25.35 3.2 to 25.3 2.3 to 25.4 Index ranges Reflections collected Independent reflections Completeness to theta Max. and min. transmission Refinement method -13<h<17-22<k<23-23<l<18-10<h<10-19<k<13-19<l<19-10<h<8-19<k<12-19<l<18-27<h<27-9<k<11-19<l<19 35200 13435 13923 10720 9616 3856 3901 3101 99.9 99.2 99.8 98.5 0.926 and 0.800 0.938 and 0.762.859 and 0.663 1.000 and 0.776 full-matrix leastsquares refinement on F 2 full-matrix leastsquares refinement on F 2 full-matrix leastsquares refinement on F 2 full-matrix leastsquares refinement on F 2 Data/ restraints/ parameters 9616 / 1 / 577 3856 / 0 / 235 3901 / 0 / 235 3101 / 0 / 181 Goodness-of-fit on F2 0.726 1.077 0.874 0.974 R1 [I>2σ(I)] 0.0421 0.1122 0.0504 0.0428 R indices (all data) R = 0.0713 and R = 0.1809 and R = 0.0695 and R = 0.0621 and wr2 = 0.1400 wr2 = 0.3803 wr2 = 0.1546 wr2 = 0.1007 Largest diff. peak and hole (e.å -3 ) 0.41 and -0.38 0.60 and -1.19 0.57 and -0.57 0.31 and 0.48 Flack parameter none none none none S36