Supporting Information. DFT as a Powerful Predictive Tool in Photoredox Catalysis: Redox Potentials and Mechanistic Analysis

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1 Supporting Information DFT as a Powerful Predictive Tool in Photoredox Catalysis: Redox Potentials and Mechanistic Analysis Taye B. Demissie,, Kenneth Ruud,, and Jørn. ansen *, Centre for Theoretical and Computational Chemistry, Department of Chemistry, UiT - The Arctic University of Norway, 9037 Tromsø, Norway Contents Page 1. Figure S1. Description of the TOC figure.. (S2) 2. Figure S2. facial and meridional isomers of PC2 and PC8 (S2) 3. Table S1. SC-ZORA/PBE-D3/TZ2P calculated Gibbs free energies and redox potentials of all the complexes (s3) 4. Table S2. SC-ZORA/PBE-D3/TZ2P calculated Gibbs free energies and redox potentials of the facial and meridional isomers of PC8....(S5) 5. Table S3. PBE-D3/TZ2P calculated nonrelativistic Gibbs free energies and redox potentials of all the complexes (s6) 6. Table S4. SC-ZORA/B3LYP-D3/TZ2P calculated Gibbs free energies and redox potentials of the ruthenium complexes (S8) 7. Figure S3. OMO and LUMO of PC1 and PC2...(S9) 8. Figure S4. OMO and LUMO of PC3 and PC4 (S10) 9. Figure S5. OMO and LUMO of PC5 and PC6 (S11) 10. Figure S6. OMO and LUMO of PC7 and PC8 (S12) 11. Figure S7. Change in Gibbs free energy of the reactions studied for the C-C bond formation between diethyl bromomalonate and N-methyl indole....(s13) 12. Figure S8. Simplified Jabłonski diagram.. (S14) 13. Figure S9. The Latimer diagram for PC1.....(S15) S1

Figure S1. Figure for table of contents (TOC): Left - the OMO (up) and LUMO (down) of PC1(+2), a catalysts used to analyze the reaction mechanism shown at the left hand side of the figure.

2 Figure S1. Figure for table of contents (TOC): Left - the OMO (up) and LUMO (down) of PC1(+2), a catalysts used to analyze the reaction mechanism shown at the left hand side of the figure. Right - the mechanism studied for the functionalization of methyl indole using bromomalonate. 1. facial and meridional isomers of PC2 and PC8 For the complexes like PC2 and PC8, there are two possible isomers, facial and meridional, shown below. As it is already established, the facial isomers are energetically favored than the meridional isomers, and hence used in the TD-DFT and redox potential calculations. X X X Y X M Y X M Y Y Y Y X facial isomer meridional isomer Figure S2. Representation of the facial and meridional isomers For PC2 and PC8 the facial isomers (N trans to C) and for PC3 and PC5 the pseudo-facial isomers were considered. The meridional isomers (N trans to N and C trans to C) were also cross-checked energetically as well as in the redox potential calculations. In these complexes, the facial isomers are stable than the meridional isomers. For instance, the facial isomer of PC8 having Ir 1+ as a central atom is stable by 5.9 kcal/mol than the meridional isomer, the one with Ir 2+ is stable by 6.3 kcal/mol than the meridional isomer, Ir 3+ by 6.1 kcal/mol, and with Ir 4+ by 2.0 kcal/mol. S2

3 Table S1. SC-ZORA/PBE-D3/TZ2P calculated Gibbs free energies of the complexes studied, change in Gibbs free energies for the redox process in gas-phase (ionization potentials), solvation free energies, final change in Gibbs free energies of solution based on the Born- aber cycle, the change in Gibbs free energies derived from the experimental redox potentials, calculated and the available experimental redox potentials, and differences between the calculated and experimental redox potentials. Numbers in brackets in the first column are oxidation states of the metals. PBE-D3 Gas-phase In MeCN ΔG ΔG ΔG Calc. Exp ΔΔG Calc. Exp. ΔE 0 G G (gas) (solv.pc) (solv.pc+) ΔG 0 ΔG 0 E 0 (abs ) E 0 (SCE ) E 0 (kcal/mol) (kcal/mol) (soln.) PC1 (+1) PC1 (+2) PC1 (+3) PC2 (+1) PC2 (+2) PC2 (+3) PC2 (+4) PC3 (+1) PC3 (+2) PC3 (+3) PC3 (+4) PC4 (+1) PC4 (+2) PC4 (+3) PC5 (+1) PC5 (+2) PC5 (+3) PC5 (+4) S3

4 PC6 (+1) PC6 (+2) PC6 (+3) PC7 (+1) PC7 (+2) PC7 (+3) PC8 (+1) PC8 (+2) PC8 (+3) PC8 (+4) S4

5 Table S2. Comparison of change in Gibbs free energies and redox potentials of the facial and meridional isomers of PC8 calculated using SC-ZORA/PBE-D3/TZ2P PBE-D3 Gas-phase In MeCN ΔG G G (gas) (kcal/mol) (kcal/mol) ΔG (solv.pc) ΔG (solv.pc+) Calc. Exp ΔΔG Calc. Exp. ΔG 0 ΔG 0 E 0 (abs ) E 0 (SCE ) E 0 (soln.) fac-pc8 PC8 (+1) PC8 (+2) PC8 (+3) PC8 (+4) mer-pc8 PC8 (+1) PC8 (+2) PC8 (+3) PC8 (+4) S5

6 Calc. Exp. Table S3. PBE-D3/TZ2P calculated nonrelativistic Gibbs free energies of the complexes studied, change in Gibbs free energies for the redox processes in gas-phase (ionization potentials), solvation free energies, final change in Gibbs free energies of solution based on the Born-aber cycle, the change in Gibbs free energies derived from the experimental redox potentials, calculated and the available experimental redox potentials, and difference between the calculated and experimental redox potentials. Numbers in brackets in the first column are oxidation states of the metals. PBE-D3 Gas-phase In MeCN ΔG ΔG ΔG Calc. Exp G(kcal/mol) G (kcal/mol) (gas) (solv.pc) (solv.pc+) ΔG 0 (soln.) ΔG 0 ΔΔG 0 E 0 (abs) E 0 (SCE) E 0 ΔE 0 PC1 (+1) PC1 (+2) PC1 (+3) PC2 (+1) PC2 (+2) PC2 (+3) PC2 (+4) PC3 (+1) PC3 (+2) PC3 (+3) PC3 (+4) PC4 (+1) PC4 (+2) PC4 (+3) PC5 (+1) PC5 (+2) PC5 (+3) PC5 (+4) S6

7 PC6 (+1) PC6 (+2) PC6 (+3) PC7 (+1) PC7 (+2) PC7 (+3) PC8 (+1) PC8 (+2) PC8 (+3) PC8 (+4) S7

8 Table S4. SC-ZORA/B3LYP-D3/TZ2P calculated Gibbs free energies, change in Gibbs free energies for the redox processes in gas-phase (ionization potentials), solvation free energies, final change in Gibbs free energies of solution based on the Born-aber cycle and redox potentials of the ruthenium complexes studied. Numbers in brackets in the first column are oxidation states of the metals. B3LYP-D3 Gas-phase In MeCN ΔG (gas) ΔG (solv.pc) ΔG G (kcal/mol) G (kcal/mol) (solv.pc+) ΔG 0 (soln.) E 0 (abs) E 0 (SCE) PC1 (+1) PC1 (+2) PC1 (+3) PC4 (+1) PC4 (+2) PC4 (+3) PC6 (+1) PC6 (+2) PC6 (+3) PC7 (+1) PC7 (+2) PC7 (+3) S8

For this complex, the OMO (the oxidation center) is located on the dz 2 orbital and LUMO is ligand based MO, and undergo metal-to-ligand charge

9 Figure S3. OMO (top) and LUMO (bottom) of PC1 (left) and PC2 (right) in different oxidation states. As it can be seen from the MO plots, for PC1, the complex that is supposed to be excited during the photochemical reaction is Ru 2+. For this complex, the OMO (the oxidation center) is located on the dz 2 orbital and LUMO is ligand based MO, and undergo metal-to-ligand charge transfer excitation ((4d π ) 6 in the ground-state and (4d π ) 5 (π*) 1 in the excited state). For PC2, it is Ir 3+ which is supposed to be excited with a metal-to-ligand charge transfer excitation. S9

For this complex, the OMO (the oxidation center) is located on the 5dz 2 orbital and LUMO is ligand based MO, and undergo metal-to-ligand charge transfer excitation ((5d π )

10 Figure S4. OMO (top) and LUMO (bottom) of PC3 (left) and PC4 (right) in different oxidation states. As it can be seen from the MO plots, for PC3, the complex that is supposed to be excited during the photochemical reaction is Ir 3+. For this complex, the OMO (the oxidation center) is located on the 5dz 2 orbital and LUMO is ligand based MO, and undergo metal-to-ligand charge transfer excitation ((5d π ) 6 in the ground-state and (5d π ) 5 (π*) 1 in the excited state). For PC4, it is Ru 2+ which is supposed to be excited with a metal-to-ligand charge transfer excitation, see the caption for Figure Supp-1 for details. Unlike Ir 3+ of PC2, the LUMO of PC3 is localized on bipyridine only. S10

For this complex, the OMO (the oxidation center) is localized ob both the metal 5dz 2 orbital and ligand π orbitals and LUMO is ligand based MO but localized on bipyridine ligand.

11 Figure S5. OMO (top) and LUMO (bottom) of PC5 (left) and PC6 (right) in different oxidation states. As it can be seen from the MO plots, for PC5, the complex that is supposed to be excited during the photochemical reaction is Ir 3+. For this complex, the OMO (the oxidation center) is localized ob both the metal 5dz 2 orbital and ligand π orbitals and LUMO is ligand based MO but localized on bipyridine ligand. It undergoes mainly metal-to-ligand charge transfer excitation. For PC6, it is Ru 2+ which is supposed to be excited with a metal-to-ligand charge transfer excitation, however the chloride π orbital also contribute for the OMO (largely metal dxz orbital) and the LUMO mainly resides on the bipyridine ligands. S11

12 Figure S6. OMO (top) and LUMO (bottom) of PC7 (left) and PC8 (right) in different oxidation states. Since there are no considerable differences of the MOs between PC1 and PC2 with PC7 and PC8, respectively, see the caption for Figure Supp-1 for explanations. S12

13 EtOOC EtOOC kcal/mol EtOOC EtOOC N C 3 SET Br Br NEt kcal/mol + Br N SET C kcal/mol NEt kcal/mol + EtOOC 9.6 kcal/mol NEt kcal/mol SET N NEt C 3 3 Br N C 3 N EtOOC C 3 N C 3 Br kcal/mol Br EtOOC N Figure S7. Change in Gibbs free energy (kcal/mol) of the reactions studied for the C-C bond formation between diethyl bromomalonate and N-methyl indole. All reactions are in DMF. The red rectangle shows the stable species. C 3 S13

14 2. Description of the methods used to calculate free energies The gas-phase and solution Gibbs free energies (G) of all the complexes in ADF are calculated from the electronic energy (E), internal energy (U) and entropy (S) obtained from the frequency calculations, all energies in kcal/mol and entropy in cal/mol.k. In ADF the electronic internal energy (E) is calculated with respect to spherical averaged neutral atoms. The nuclear internal energy is the sum of zero point energy and 3kT terms with small correction terms. ence the total internal energy is the sum of the nuclear internal energy and the electronic energy (U + E). The temperature (T) used for the thermodynamic DFT calculations is K. The following thermodynamic equation is used to derive the Gibbs free energy: G TS ( U E PV ) TS ( U E nrt ) TS where is the enthalpy, P is pressure, V is volume and R is the universal gas constant. The 0-0 transition energy (E 0-0 ) in MeCN is calculated based on the simplified Jabłonski diagram and the equation given below: Figure S8. Simplified Jabłonski diagram E E E R E R vertical fluo. GS ES GS GS 0 0 [ ( ) ( )] where E vertical fluo. is the TD-DFT vertical fluorescence energy calculated on the excited-state optimized geometry, E GS (R ES ) is the ground-state energy calculated from the excited-state S14

15 optimized geometry, E GS (R GS ) is the ground-state energy calculated from the ground-state optimized geometry. 3. Description of the methods used to calculate excited-state redox potentials The excited-state redox potentials were determined from the ground-state redox potentials and the 0-0 transition energy using the Latimer diagram. As an example the Latimer diagram for PC1 is shown below. Ru(bpy) 3 2+* 0.84 V E ev V Ru(bpy) V 1.26 V 2+ Ru(bpy) 3 Ru(bpy) 3 3+ Figure S9. The Latimer diagram for PC1 o E (Ru ) E (Ru ) E (Ru ) 2 */ 2 */2 o 2 / (-1.28) = 0.84V o E (Ru ) E (Ru ) E (Ru ) 3 /2 * o 3 /2 2 */ = 0.86V All the terms given in the Latimer diagram are experimental values. In our calculated values, the E 0-0 energies are calculated using TD-DFT formalism using the steps and the redox potentials using the procedures stated on page S14. S15

Supporting Information

Supporting Information Formation of Ruthenium Carbenes by gem-hydrogen Transfer to Internal Alkynes: Implications for Alkyne trans-hydrogenation Markus Leutzsch, Larry M. Wolf, Puneet Gupta, Michael Fuchs,