Photochemical Production of Ethane from an Iridium Methyl Complex

Transcription

1 Supporting Information for Photochemical Production of Ethane from an Iridium Methyl Complex Catherine L. Pitman and Alexander J. M. Miller* Department of Chemistry, University of North Carolina at Chapel Hill, NC , USA

2 Contents I. NMR Spectra of New Complexes S3 II. Photophysical Characterization S10 III. Reactions of [Cp*Ir(bpy)(CH3)] + ([2] + ) S14 IV. Crystallographic Details S28 V. Computational Details S37 VI. References S43 S2

3 I. NMR Spectra of New Complexes Figure S1. 1 H NMR spectrum of [Cp*Ir(bpy)(CH3)][I] ([2][I]) in CD3CN. S3

4 Figure S2. 13 C{ 1 H} NMR spectrum of [Cp*Ir(bpy)(CH3)][I] ([2][I]) in CD3CN. S4

5 Figure S3. 1 H NMR spectrum of [Cp*Ir(bpy)(CH3)][PF6] ([2][PF6]) in CD3CN. S5

6 Figure S4. 13 C{ 1 H} NMR spectrum of [Cp*Ir(bpy)(CH3)][PF6] ([2][PF6]) in CD3CN. S6

7 Figure S5. 1 H NMR spectrum of [Cp*Ir(bpy)(I)] + ([4] + ) in CD3CN. Figure S6. Absorptivity of [Cp*Ir(bpy)(I)] + in CH3CN. Sample prepared by addition of 3 equiv NaI to a solution of [Cp*Ir(bpy)(OH2)][OTf]2. Ir concentration determined by ICP-MS. S7

8 Figure S7. 1 H NMR spectrum of [Cp*Ir(bpy)((CH2)4CHCH2)][Br] ([5][Br]) in CD3CN. S8

9 Figure S8. 13 C{ 1 H} NMR spectrum of [Cp*Ir(bpy)((CH2)4CHCH2)][Br] ([5][Br]) in CD3CN. S9

10 II. Photophysical Characterization Fit of UV-Vis Absorbance The absorbance at 420 nm was fit to two Gaussian curves using the multi-peak fitting tool of Igor Pro 6.2. Fitting the entire spectrum (including the absorbances in the UV) with five Guassians gave the same fit for the MLCT features. Figure S9. Fit of the MLCT feature of [2][PF6] in CH3CN to two Guassian curves. Photoluminescence quantum yield Four samples of [Ru(bpy)3][Cl]2 and of [2][PF6] with absorbance less than 0.1 were prepared in CH3CN. Samples were thermostated at 298 K, excited with a 450 W Xe light source passed through a monochromator for 450 nm with a 5 nm band width, and detected from 515 to 950 nm with a 20 nm band width. A 300 nm long pass filter was used on the excitation side, and a 515 nm long pass filter (Newport 20CGA-515) was used on the emission side. The absolute quantum yield for [2][PF6] was determined by comparing the detected counts of [2][PF6] with [Ru(bpy)3][Cl]2 according to the equation S10

11 Φ Ir = Φ Ru ( I Ir ) ( A Ru ) ( η 2 Ir A Ir I Ru 2 η ) Ru where ΦM is the quantum yield of that species, IM/AM is the slope of integrated counts versus sample absorbance (Figure S10), and ηm is the refractive index of the solvent. 1 In this case, both reference and unknown were measured in CH3CN so the ηm term is unity. The quantum yield of [Ru(bpy)3][Cl]2 is known to be 9.4% under these conditions. 2 From this treatment, the absolute photoluminescence quantum yield of [2] + was determined to be 0.04%. Figure S10. Counts of the phosphorescence of [Ru(bpy)3][Cl]2 (red circles) and [2][PF6] (blue squares) for four separate concentrations integrated from 515 to 950 nm using a NIR InGAs detector. Comparison of the slopes of these lines allows for the calculation of the absolute photoluminescent quantum yield of [2][PF6]. S11

12 Excited State Thermochemistry Figure S11. Instrument and background corrected emission (green) of [2][PF6] in CH3CN solution with excitation at 420 nm. The extrapolation of the high energy edge used to measure ΔGST (dashed red) intercepts the x-axis at cm 1 or 50 kcal mol 1. Figure S12. Cyclic voltammetry of reduction of [2][PF6] in CH3CN with 0.1 M [ n Bu4N][PF6]. S12

13 Figure S13. Cyclic voltammetry of oxidation of [2][PF6] in CH3CN with 0.1 M [ n Bu4N][PF6], showing that the reduction is apparent even at 50 mv/s. Scheme S1. Excited State Reduction Potentials S13

14 III. Reactions of [Cp*Ir(bpy)(CH3)] + ([2] + ) Figure S14. Representative 1 H NMR spectrum of a 6.7 mm [2][PF6], 0.1 M CH3I with a 3 mm mesitylene internal standard in CD3CN after irradiation with a 443 nm light source for 3.5 hours. The iridium species has been converted to [4] + while ethane, methane, and propionitrile have appeared. S14

15 Figure S15. 1 H NMR spectrum of [2][I] and CH3OTs photolyzed with 443 nm light for 22 hours, forming [4] +, methane, and ethane. S15

16 Figure S16. 1 H NMR spectrum of [2][I] and 7 eq pyridine in CD3CN photolyzed with 443 nm light for 5 hours. Some [4] + was formed from reaction with CH3I remaining from the synthesis of [2][I] (halide abstraction to [2][PF6] removes all CH3I), but no formation of 1-methylpyridinium iodide was observed. S16

17 Figure S17. 1 H NMR spectrum of 3 and 5 eq 1,4-dimethylpyridinium iodide in CD3CN after mixing in the dark for 24 hours. No methylation of 3 (to form [2] + ) was observed. S17

18 Figure S18. 1 H NMR spectrum of 6 mm [2][PF6] and 0.15 M AcOH in CD3CN (bottom) photolyzed with 443 nm light for 3.5 hours (top). Methane and [Cp*Ir(bpy)(OAc)] + are the primary products. S18

19 Figure S19. Growth of 13 CH4, 13 CH3D, 12 CH4, and 12 CH3D over 443 nm 30 min of photolysis of 12.5 mm [2][PF6] and 80 mm 13 CH3I in CD3CN with a 3 mm mesitylene internal standard. The downfield satellite was used for 13 C-containing methane integration. S19

20 Figure S20. Growth of 13 C- and 12 C-containing ethane over 30 min of 443 nm photolysis of 12.5 mm [2][PF6] and 80 mm 13 CH3I in CD3CN with a 3 mm mesitylene internal standard. The initial spectrum was manually subtracted. Evidence of Radical Mechanism through Radical Clock A solution of [Cp*Ir(bpy)(CH2CH2CH2CH2CHCH2)][Br] ([5][Br])in CD3CN was photolyzed for 60 min with a Thor 443 LED at 25% power. During photolysis, the solution darkened, and 1 H NMR spectroscopy showed the consumption of starting material, formation of methylcyclopentane (confirmed by spiking with and authentic sample), 1,5-hexadiene, Cp*Ir(bpy), [Cp*Ir(bpy)(Br)] +, and an new Ir product. MS confirmed the identification of the bromide (calc: , obs: ) and suggested that the new Ir product was a S20

21 [Cp*Ir(bpy)(C6H11)] + fragment (calc: , obs: ). Given the consumption of starting material, this may be coordination of the cyclized product, [Cp*Ir(bpy)(CH2C5H9)] +. Figure S21. 1 H NMR spectra of [5][Br] in CD3CN (bottom) photolyzed with 443 nm light for 40 min (top). The consumption of [5] + is most clearly identified by the absence of the olefinic protons at 4.75 ppm and 5.55 ppm. The CH3 doublet of methylcyclopentane is at 0.95 ppm. Other organic products 1,5-hexadiene and methylenecylclopentane are labeled in the olefinic region. Coupling to upfield protons was observed for these species, and all resonances were identified except one resonance of methylenecylclopentane, which comes under the solvent residual. The species suggested to be the ring-closed organometallic product is labeled Ir R. Coupling of the peak at 0.4 ppm is observed to peaks in the alkane region, and this product is not volatile, remaining after all the organic products had been removed in vacuo. S21

22 Assessing self-quenching by steady-state and time-correlated photoluminescent methods. The possibility of self-quenching was investigated by measuring the changes in photoluminescence with concentration of [2][PF6]. Because of the high absorbances of samples required to access the largest possible range of concentration, inner filter effects were corrected for according to the method of Albinsson and coworkers, 3 as we have previously described. 4 Table S1. Steady State Emission data for variable concentrations of [2][PF6] in CH3CN at room temperature. [[2][PF6]] Iobs A420 a Icorr Inorm b I0/I c (mm) a Absorbance of sample at excitation wavelength of 420 nm. b Inner filter effect corrected emission. c I 0 is the extrapolation of I norm to infinite dilution of [2] +, which was determined to be I is the normalized emission value. Figure S22. Self-quenching Stern-Volmer analysis for [2][PF6] in CH3CN at room temperature. I0 is the emission extrapolated to infinite dilution. I is the corrected and normalized emission at a given concentration of [2] +. The absence of upward trend indicates the absence of selfquenching. S22

23 Figure S23. Photoluminescent lifetime of [2][PF6] in CH3CN solution measured by timecorrelated single photon counting. Laser excitation at nm source with 73.3 ps pulse width at 2 MHz pulse rate. Emission detected at 680 nm with a 5 nm bandwidth. The independence of lifetime with concentration indicates the absence of self-quenching. Figure S24. Photoluminescent lifetime of [2][PF6] in CH3CN solution with varying concentration of CH3I. Time-correlated single photon counting laser excitation at nm source with 73.3 ps pulse width at 2 MHz pulse rate. Emission detected at 680 nm with a 5 nm bandwidth. The independence of lifetime with CH3I concentration indicates the absence of quenching by the substrate. S23

24 Figure S25. Representative experiment following the reaction of [2][PF6] with CH3I in CH3CN. The sample was irradiated at 443 nm (1.58 x 10 6 moles of photons min 1 ) in 30 s intervals for the first 5 min (from the red trace to the blue trace) to calculate quantum yield. Photolysis for longer periods produces the green spectrum. The expected spectrum of [4] + is shown in the dashed black spectrum. Order in reaction of [2] + with AcOH Figure S26. UV-Vis spectra of [2][PF6] with AcOH irradiated at 443 nm and stirred during data collection. S24

25 Figure S27. Dependence of quantum yield on [AcOH] (blue squares) and [[2] + ] (red circles) in CH3CN photolyzed with 443 nm light. The dashed-line marks the constant concentration of AcOH and [2] + (0.1 M and 0.12 mm respectively) held while the other reagent varied. The lack of dependence in AcOH indicates the reaction is zero order in substrate, while the lack of dependence on [2] + indicates an overall first order as [2] + is the chromophore. Figure S28. Growth of Ir-containing products on 443 nm photolysis of 1 mm (red), 2 mm (purple), 4 mm (blue), and 8 mm (green) [2][PF6] in CD3CN with 10 mm AcOH. The consistent increases indicate quantum yield is not changing across this concentration range. S25

26 Figure S29. Quantum yields of reactions of [2][PF6] with CH3I in CH3CN with and without 0.1 M [ n Bu4N][PF6]. Error bars are standard deviations of four samples each prepared on the same day. Figure S30. 1 H NMR spectrum of [2][PF6] and 0.1 M CH3I in 9:1 CH3CN:CD3CN photolyzed with 443 nm light for 3.5 hours. Methane, succinonitrile, and [4] + are formed. S26

27 Figure S31. Quantum yields of reactions of [2][PF6] with CH3I in CH3CN and with CD3I in CD3CN. Error bars are estimated uncertainty from one standard deviation of four independent samples of [2][PF6] in CH3CN with CH3I. S27

28 IV. Crystallographic Details Table S2. Cp*Ir CH3 distances in the Cambridge Structural Database CSD Code DOI Ir-CH 3 Distance BAHWOW /C BEKZEY /om BEKZIC /om BEWREB /ja049225q 2.22 CUKJID /om500910t 2.1 HAWWIL /ja00075a IBAZUI /c1nj20244h LIBFUY /om LOQGED /om990255p MUJTER /chem NEUREL /om OHULEI /S0022- XIFVIR 328X(03) /b107451m XIFVOD /b107451m YULZIQ /ja512905t ZOSHUM /om Table S3 Crystal data and structure refinement for [Cp*Ir(bpy)(Me)][I] ([2][I], x ). Identification code x Empirical formula C21H26N2IIr Formula weight Temperature/K 100 Crystal system monoclinic Space group P21/n a/å (8) b/å (6) c/å (14) α/ 90 S28

29 β/ (4) γ/ 90 Volume/Å (2) Z 4 ρcalcg/cm μ/mm F(000) Crystal size/mm Radiation CuKα (λ = ) 2Θ range for data collection/ to Index ranges -14 h 14, -10 k 10, -24 l 24 Reflections collected Independent reflections 3833 [Rint = , Rsigma = ] Data/restraints/parameters 3833/0/232 Goodness-of-fit on F Final R indexes [I>=2σ (I)] R1 = , wr2 = Final R indexes [all data] R1 = , wr2 = Largest diff. peak/hole / e Å /-1.18 S29

30 Table S4 Bond Lengths for x Atom Atom Length/Å Atom Atom Length/Å Ir1 N (4) C5 C (6) Ir1 N (4) C6 C (7) Ir1 C (4) C7 C (7) Ir1 C (4) C8 C (7) Ir1 C (5) C9 C (7) Ir1 C (4) C11 C (7) Ir1 C (4) C11 C (7) Ir1 C (5) C11 C (7) N1 C (6) C12 C (6) N1 C (6) C12 C (7) N2 C (6) C13 C (6) N2 C (6) C13 C (6) C1 C (7) C14 C (6) C2 C (7) C14 C (6) C3 C (7) C15 C (6) C4 C (6) Table S5 Bond Angles for x Atom Atom Atom Angle/ Atom Atom Atom Angle/ N1 Ir1 C (17) N1 C5 C (4) N1 Ir1 C (16) C4 C5 C (4) N1 Ir1 C (15) N2 C6 C (4) N1 Ir1 C (15) N2 C6 C (4) N1 Ir1 C (16) C7 C6 C (4) N1 Ir1 C (17) C8 C7 C (4) N2 Ir1 N (15) C9 C8 C (4) N2 Ir1 C (17) C8 C9 C (4) N2 Ir1 C (16) N2 C10 C (4) N2 Ir1 C (16) C12 C11 Ir1 70.6(3) N2 Ir1 C (15) C12 C11 C (4) N2 Ir1 C (16) C12 C11 C (4) N2 Ir1 C (17) C15 C11 Ir1 70.8(2) C11 Ir1 C (17) C15 C11 C (4) C11 Ir1 C (17) C16 C11 Ir (3) C11 Ir1 C (17) C11 C12 Ir1 71.3(3) S30

31 C12 Ir1 C (18) C11 C12 C (4) C12 Ir1 C (17) C11 C12 C (4) C12 Ir1 C (16) C13 C12 Ir1 73.0(3) C12 Ir1 C (17) C13 C12 C (4) C13 Ir1 C (17) C17 C12 Ir (3) C15 Ir1 C (17) C12 C13 Ir1 68.7(2) C15 Ir1 C (17) C12 C13 C (4) C21 Ir1 C (18) C14 C13 Ir1 71.6(3) C21 Ir1 C (18) C14 C13 C (4) C21 Ir1 C (17) C14 C13 C (4) C21 Ir1 C (18) C18 C13 Ir (3) C21 Ir1 C (18) C13 C14 Ir1 71.4(3) C1 N1 Ir (3) C13 C14 C (4) C1 N1 C (4) C13 C14 C (4) C5 N1 Ir (3) C15 C14 Ir1 69.1(2) C6 N2 Ir (3) C15 C14 C (4) C10 N2 Ir (3) C19 C14 Ir (3) C10 N2 C (4) C11 C15 Ir1 70.6(2) N1 C1 C (4) C11 C15 C (4) C1 C2 C (4) C11 C15 C (4) C4 C3 C (4) C14 C15 Ir1 72.6(2) C3 C4 C (4) C14 C15 C (4) N1 C5 C (4) C20 C15 Ir (3) Table S6 Torsion Angles for x A B C D Angle/ A B C D Angle/ Ir1 N1 C1 C (3) C8 C9 C10 N2 2.8(7) Ir1 N1 C5 C (3) C10 N2 C6 C (4) Ir1 N1 C5 C6 5.6(5) C10 N2 C6 C7-1.2(6) Ir1 N2 C6 C5-6.7(5) C11 C12 C13 Ir1 63.5(3) Ir1 N2 C6 C (3) C11 C12 C13 C14 3.0(5) Ir1 N2 C10 C (3) C11 C12 C13 C (4) Ir1 C11 C12 C (3) C12 C11 C15 Ir1-60.7(3) Ir1 C11 C12 C (5) C12 C11 C15 C14 3.1(5) Ir1 C11 C15 C (3) C12 C11 C15 C (4) Ir1 C11 C15 C (5) C12 C13 C14 Ir1 58.8(3) Ir1 C12 C13 C (3) C12 C13 C14 C15-1.0(5) S31

32 Ir1 C12 C13 C (4) C12 C13 C14 C (4) Ir1 C13 C14 C (3) C13 C14 C15 Ir1 61.3(3) Ir1 C13 C14 C (5) C13 C14 C15 C11-1.3(5) Ir1 C14 C15 C (3) C13 C14 C15 C (4) Ir1 C14 C15 C (5) C15 C11 C12 Ir1 60.9(3) N1 C1 C2 C3-0.8(7) C15 C11 C12 C13-3.7(5) N1 C5 C6 N2 0.7(5) C15 C11 C12 C (4) N1 C5 C6 C (4) C16 C11 C12 Ir (5) N2 C6 C7 C8 1.5(7) C16 C11 C12 C (4) C1 N1 C5 C4 0.8(6) C16 C11 C12 C17 3.9(8) C1 N1 C5 C (4) C16 C11 C15 Ir (5) C1 C2 C3 C4 0.8(7) C16 C11 C15 C (4) C2 C3 C4 C5 0.0(7) C16 C11 C15 C20-1.6(7) C3 C4 C5 N1-0.8(7) C17 C12 C13 Ir (5) C3 C4 C5 C (4) C17 C12 C13 C (4) C4 C5 C6 N (4) C17 C12 C13 C18-5.3(7) C4 C5 C6 C7-0.5(7) C18 C13 C14 Ir (5) C5 N1 C1 C2 0.0(7) C18 C13 C14 C (4) C5 C6 C7 C (4) C18 C13 C14 C19 0.1(8) C6 N2 C10 C9-0.9(7) C19 C14 C15 Ir (5) C6 C7 C8 C9 0.4(7) C19 C14 C15 C (4) C7 C8 C9 C10-2.5(7) C19 C14 C15 C20 2.9(8) Experimental Single crystals of C21H26N2IIr x were grown from vapor diffusion of ether into acetonitrile. A suitable crystal was selected and mounted on a Bruker APEX-II CCD diffractometer. The crystal was kept at 100 K during data collection. Using Olex2 [1], the structure was solved with the olex2.solve [2] structure solution program using Charge Flipping and refined with the XL [3] refinement package using Least Squares minimisation. 1. Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H. (2009), J. Appl. Cryst. 42, Bourhis, L.J., Dolomanov, O.V., Gildea, R.J., Howard, J.A.K., Puschmann, H. (2015). Acta Cryst. A71, Sheldrick, G.M. (2008). Acta Cryst. A64, Crystal structure determination of x Crystal Data for C21H26N2IIr (M = g/mol): monoclinic, space group P21/n (no. 14), a = (8) Å, b = (6) Å, c = (14) Å, β = (4), V = (2) Å 3, Z = 4, T = 100 K, μ(cukα) = mm -1, Dcalc = g/cm 3, reflections measured (7.852 S32

33 2Θ ), 3833 unique (Rint = , Rsigma = ) which were used in all calculations. The final R1 was (I > 2σ(I)) and wr2 was (all data). Refinement model description Number of restraints - 0, number of constraints - unknown. Details: 1. Fixed Uiso At 1.2 times of: All C(H) groups At 1.5 times of: All C(H,H,H) groups 2.a Aromatic/amide H refined with riding coordinates: C1(H1), C2(H2), C3(H3), C4(H4), C7(H7), C8(H8), C9(H9), C10(H10) 2.b Idealised Me refined as rotating group: C16(H16A,H16B,H16C), C17(H17A,H17B,H17C), C18(H18A,H18B,H18C), C19(H19A,H19B, H19C), C20(H20A,H20B,H20C), C21(H21A,H21B,H21C) S33

34 Table S7 Crystal data and structure refinement for Cp*Ir(bpy) (3, x ). Identification code x Empirical formula C20H23IrN2 Formula weight Temperature/K Crystal system monoclinic Space group P21/n a/å (2) b/å (2) c/å (5) α/ 90 β/ (9) γ/ 90 Volume/Å (7) Z 4 ρcalcg/cm μ/mm F(000) Crystal size/mm Radiation CuKα (λ = ) 2Θ range for data collection/ to Index ranges -11 h 11, -11 k 11, -24 l 24 Reflections collected Independent reflections 3218 [Rint = , Rsigma = ] Data/restraints/parameters 3218/0/213 Goodness-of-fit on F Final R indexes [I>=2σ (I)] R1 = , wr2 = Final R indexes [all data] R1 = , wr2 = Largest diff. peak/hole / e Å /-1.16 Table S8 Bond Lengths for x Atom Atom Length/Å Atom Atom Length/Å Ir1 N (3) C5 C (5) Ir1 N (3) C6 C (5) Ir1 C (4) C7 C (6) Ir1 C (3) C8 C (6) Ir1 C (4) C9 C (6) Ir1 C (4) C11 C (5) Ir1 C (3) C11 C (5) N1 C (5) C11 C (5) N1 C (5) C12 C (5) S34

35 N2 C (5) C12 C (5) N2 C (5) C13 C (5) C1 C (6) C13 C (5) C2 C (6) C14 C (5) C3 C (6) C14 C (5) C4 C (5) C15 C (5) Table S9 Bond Angles for x Atom Atom Atom Angle/ Atom Atom Atom Angle/ N1 Ir1 C (13) C5 C6 C (3) N1 Ir1 C (13) C8 C7 C (4) N1 Ir1 C (13) C7 C8 C (4) N1 Ir1 C (13) C10 C9 C (4) N1 Ir1 C (13) C9 C10 N (4) N2 Ir1 N (12) C12 C11 Ir1 70.0(2) N2 Ir1 C (13) C12 C11 C (4) N2 Ir1 C (13) C15 C11 Ir1 70.0(2) N2 Ir1 C (13) C15 C11 C (3) N2 Ir1 C (13) C15 C11 C (4) N2 Ir1 C (13) C16 C11 Ir (3) C12 Ir1 C (14) C11 C12 Ir1 72.5(2) C13 Ir1 C (14) C11 C12 C (4) C13 Ir1 C (14) C13 C12 Ir1 70.5(2) C13 Ir1 C (13) C13 C12 C (3) C13 Ir1 C (13) C13 C12 C (3) C14 Ir1 C (14) C17 C12 Ir (3) C14 Ir1 C (14) C12 C13 Ir1 71.7(2) C14 Ir1 C (14) C12 C13 C (3) C15 Ir1 C (14) C12 C13 C (3) C15 Ir1 C (13) C14 C13 Ir1 71.0(2) C1 N1 Ir (3) C14 C13 C (4) C1 N1 C (3) C18 C13 Ir (2) C5 N1 Ir (2) C13 C14 Ir1 70.7(2) C6 N2 Ir (2) C13 C14 C (3) C10 N2 Ir (2) C13 C14 C (4) C10 N2 C (3) C15 C14 Ir1 71.3(2) C2 C1 N (4) C15 C14 C (4) C1 C2 C (4) C19 C14 Ir (3) C4 C3 C (4) C11 C15 Ir1 72.5(2) C3 C4 C (4) C11 C15 C (3) S35

36 N1 C5 C (3) C11 C15 C (4) N1 C5 C (3) C14 C15 Ir1 70.4(2) C6 C5 C (3) C14 C15 C (4) N2 C6 C (3) C20 C15 Ir (3) N2 C6 C (3) Experimental Single crystals of C20H23IrN2 [x ] were grown from slow evaporation from THF. A suitable crystal was selected and mounted on a 'Bruker APEX-II CCD' diffractometer. The crystal was kept at K during data collection. Using Olex2 [1], the structure was solved with the olex2.solve [2] structure solution program using Charge Flipping and refined with the ShelXL [3] refinement package using Least Squares minimisation. 1. Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H. (2009), J. Appl. Cryst. 42, Bourhis, L.J., Dolomanov, O.V., Gildea, R.J., Howard, J.A.K., Puschmann, H. (2015). Acta Cryst. A71, Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8. Crystal structure determination of [x ] Crystal Data for C20H23IrN2 (M = g/mol): monoclinic, space group P21/n (no. 14), a = (2) Å, b = (2) Å, c = (5) Å, β = (9), V = (7) Å 3, Z = 4, T = K, μ(cukα) = mm -1, Dcalc = g/cm 3, reflections measured ( Θ ), 3218 unique (Rint = , Rsigma = ) which were used in all calculations. The final R1 was (I > 2σ(I)) and wr2 was (all data). Refinement model description Number of restraints - 0, number of constraints - unknown. Details: 1. Fixed Uiso At 1.2 times of: All C(H) groups At 1.5 times of: All C(H,H,H) groups 2.a Aromatic/amide H refined with riding coordinates: C1(H1), C2(H2), C3(H3), C4(H4), C7(H7), C8(H8), C9(H9), C10(H10) 2.b Idealised Me refined as rotating group: C16(H16A,H16B,H16C), C17(H17A,H17B,H17C), C18(H18A,H18B,H18C), C19(H19A,H19B, H19C), C20(H20A,H20B,H20C) S36

37 V. Computational Details 5 Table S10. Characterizations of the excitations of 3 calculated using the M06 functional. Wavelength is reported in nm, f is the oscillator strength of the transition, 1e is the highest percentage one-electron transition, and CT describes the location of electron density in the two MOs involved in the highest percentage one-electron transition. Transition λ (nm) f 1e HOMO LUMO HOMO-1 LUMO HOMO-1 LUMO HOMO LUMO HOMO-1 LUMO HOMO LUMO HOMO-3 LUMO HOMO LUMO HOMO-2 LUMO HOMO-1 LUMO HOMO LUMO HOMO LUMO HOMO-1 LUMO HOMO LUMO HOMO-2 LUMO HOMO-1 LUMO HOMO-1 LUMO HOMO LUMO HOMO LUMO HOMO-1 LUMO+4 Transitions of Interest Excited State 3: Singlet-?Sym ev nm f= <S**2>= > > Excited state symmetry could not be determined. Excited State 4: Singlet-?Sym ev nm f= <S**2>= > > Excited state symmetry could not be determined. S37

38 Input File for the geometry optimization of [2] + %chk=cpirmebpy_opt.chk %mem=16gb %nprocshared=4 # opt freq=noraman m06/gen pseudo=read scrf=(smd,solvent=acetonitrile) nosymm guess=mix 5d 7f scf=xqc [Cp*Ir(Me)bpy]+ optimization 1 1 C C C C C H H H H C C C C H C H H H N N Ir C C C C C C H H H C H H S38

39 H C H H H C H H H C H H H C H H H C N H 6-311G** **** Ir 0 S S S P P P D S39

40 D **** IR 0 IR-ECP 4 60 g-ul potential s-ul potential p-ul potential d-ul potential f-ul potential S40

41 TD-DFT Calculation for [2] + %chk=cpirmebpy_td2.chk %mem=16gb %nprocshared=8 #p m06/gen pseudo=read guess=mix scf=xqc 5d 7f nosymm td(50-50,nstates=20) scrf=(smd,solvent=acetonitrile) pop=full gfinput [Cp*Ir(Me)bpy]+ TD-DFT at optimized singlet 1 1 Coordinates in DFT geometries.xyz C N H 6-311G** **** Ir 0 S S S P P P D D S41

42 **** IR 0 IR-ECP 4 60 g-ul potential s-ul potential p-ul potential d-ul potential f-ul potential S42

43 VI. References (1) Williams, A. T. R.; Winfield, S. A.; Miller, J. N. Analyst 1983, 108, (2) Suzuki, K.; Kobayashi, A.; Kaneko, S.; Takehira, K.; Yoshihara, T.; Ishida, H.; Shiina, Y.; Oishi, S.; Tobita, S. Phys. Chem. Chem. Phys. 2009, 11, (3) Kubista, M.; Sjöback, R.; Eriksson, S.; Albinsson, B. Analyst 1994, 119, (4) Chambers, M. B.; Kurtz, D. A.; Pitman, C. L.; Brennaman, M. K.; Miller, A. J. M. J. Am. Chem. Soc. 2016, 138, (5) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci, B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, J. A. J.; Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N.; Millam, N. J.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, O.; Foresman, J. B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J. Gaussian 09, Revision D.01; Gaussian, Inc: Wallingford, CT, S43