Title Page
Contents
ABSTRACT IN KOREAN 31
Part Ⅰ. Synthesis, Characterization, and Reactivity Studies of Novel Homogeneous Transition Metal Catalysts 34
Chapter Ⅰ. Metal Ion-Coupled Electron Transfer Reactivities on a Series of Unprecedented Mononuclear Nonheme Cobalt(III)-Iodosylbenzene Complexes 35
Ⅰ. INTRODUCTION 35
Ⅱ. EXPERIMENTAL SECTION 39
Ⅲ. RESULTS AND DISCUSSION 50
Ⅳ. CONCLUSION 91
Ⅴ. REFERENCES 92
Chapter Ⅱ. Synthesis, Characterization and Catalytic Activity of a Mononuclear Nonheme Copper(II)-Iodosylbenzene Adduct 96
Ⅰ. INTRODUCTION 96
Ⅱ. EXPERIMENTAL SECTION 99
Ⅲ. RESULTS AND DISCUSSION 103
Ⅳ. CONCLUSION 117
Ⅴ. REFERENCES 118
Chapter Ⅲ. An End-on Bis(μ-Hydroxo) Dimanganese(II,III) Azide Complex for C-H Bond and O-H Bond Activation Reactions 122
Ⅰ. INTRODUCTION 122
Ⅱ. EXPERIMENTAL SECTION 124
Ⅲ. RESULTS AND DISCUSSION 130
Ⅳ. CONCLUSION 163
Ⅴ. REFERENCES 164
Chapter Ⅳ. Mono- and Dinuclear Zinc Complexes Bearing Identical Bis(Thiosemicarbazone) Ligand That Exhibit Alkaline Phosphatase-Like Catalytic Reactivity 167
Ⅰ. INTRODUCTION 167
Ⅱ. EXPERIMENTAL SECTION 170
Ⅲ. RESULTS AND DISCUSSION 173
Ⅳ. CONCLUSION 209
Ⅴ. REFERENCE 211
Part Ⅱ. Incorporation of Transition Metal Ion to Homogeneous and Heterogeneous Catalysts to Improve Their Reactivities 214
Chapter Ⅰ. High-Voltage Symmetric Nonaqueous Redox Flow Battery Based on Modularly Tunable Trimetallic Coordination Cluster Compounds with Multielectron Storage Capability 215
Ⅰ. INTRODUCTION 215
Ⅱ. EXPERIMENTAL SECTION 219
Ⅲ. RESULTS AND DISCUSSION 227
Ⅳ. CONCLUSION 252
Ⅴ. REFERENCES 253
Chapter Ⅱ. W-O Bond Shortening by Doping of First-Row Transition Metal Ions on WO₃ NPs That Enhances Theirs Catalytic Potency 256
Ⅰ. INTRODUCTION 256
Ⅱ. EXPERIMENTAL SECTION 259
Ⅲ. RESULTS AND DISCUSSION 263
Ⅳ. CONCLUSION 287
Ⅴ. REFERENCES 288
Chapter Ⅲ. Selective Oxidation of Biomass Molecules by Modified ZnO Nanoparticles via Charge Mismatch with Doped Co Ions 292
Ⅰ. INTRODUCTION 292
Ⅱ. EXPERIMENTAL SECTION 295
Ⅲ. RESULTS AND DISCUSSION 297
Ⅳ. CONCLUSION 313
Ⅴ. REFERENCES 314
ABSTRACT 317
PART Ⅰ. Synthesis, Characterization, and Reactivity Studies of Novel Homogeneous Transition Metal Catalysts 53
Chapter Ⅰ. Metal Ion-Coupled Electron Transfer Reactivities on a Series of Unprecedented Mononuclear Nonheme Cobalt(III)-Iodosylbenzene Complexes 53
Table 1. Crystallographic Data and Refinements for 1 53
Table 2. Selected Bond Distances (Å) and Angles (°) for 1 54
Table 3. Structural Parameters from EXAFS Fits 67
Table 4. Oxidation Potentials (Eₒₓ) of One-Electron Donors, Rate Constants (kₑₜ), and Driving Force (-△Gₑₜ) for ET from One-Electron Donors to 2 and... 75
Chapter Ⅲ. An End-on Bis(μ-Hydroxo) Dimanganese(II,III) Azide Complex for C-H Bond and O-H Bond Activation Reactions 133
Table 1. Crystallographic Data and Refinements for [Mn(HN3O2)(ClO₄)](ClO₄), and 1 133
Table 2. Selected Bond Distances (Å) and Angles (°) for [Mn(HN3O2)(ClO₄)](ClO₄) and 1 134
Table 3. Mulliken Spin Density Distribution of [Mn₂(BPA)₂(μ-OH)₂(N₃)₂]⁺ (2a) and [Mn₂(BPA)₂(μ-N₃)₂(OH)₂]⁺ (2b) Calculated at the B3LYP/Def2-... 146
Table 4. Relative Energies (in kcal mol⁻¹) of [Mn₂(BPA)₂(μ-OH)₂(N₃)₂]⁺(2a) and [Mn₂(BPA)₂(μ-N₃)₂(OH)₂]⁺ (2b) Calculated at the B3LYP/Def2-... 146
Table 5. Relative Energies (in kcal mol⁻¹) of [Mn₂(HN3O2)₂(μ-OH)₂(N₃)₂]⁺(2a) and [Mn₂(HN3O2)₂(μ-N₃)₂(OH)₂]⁺ (2b) Calculated at the... 147
Table 6. Mulliken Spin Density Distribution of [Mn₂(HN3O2)₂(μ-OH)₂(N₃)₂]⁺ (2a) and [Mn₂(HN3O2)₂(μ-N₃)₂(OH)₂]⁺ (2b) Calculated at the... 147
Table 7. Selected Geometries of [Mn₂(HN3O2)₂(μ-OH)₂(N₃)₂]⁺ (2a) and [Mn₂(HN3O2)₂(μ-N₃)₂(OH)₂]⁺ (2b) Calculated at the B3LYP/Def2-SVP Level 148
Table 8. Relative Energies (in kcal mol⁻¹) of ⁵[MnIII(HN3O2)(OH)(N3)]⁺ C-H Activation Reaction of 1,4-Cyclohexadiene Calculated at the...[이미지참조] 155
Table 9. Relative Energies (in kcal mol⁻¹) of ¹⁰[Mn₂(HN3O2)₂(μ-OH)₂(N₃)₂]⁺ (2a) in C-H Activation Reaction of 1,4-Cyclohexadiene, Performed... 157
Table 10. Relative Energies (in kcal mol⁻¹) of [Mn₂(HN3O2)₂(μ-OH)₂(N₃)₂]⁺ (2a) in C-H Activation Reaction of 1,4-Cyclohexadiene in a... 158
Chapter Ⅳ. Mono- and Dinuclear Zinc Complexes Bearing Identical Bis(Thiosemicarbazone) Ligand That Exhibit Alkaline Phosphatase-Like Catalytic Reactivity 182
Table 1. Relative Energies in kcal mol⁻¹ for the Monomeric Species 182
Table 2. Kinetic Data for Hydrolysis of 4-NPP by complexes 1, 2 and BDNPP by Other Reported Zinc Complexes 196
Table 3. Relative Energies in kcal mol⁻¹ for the Dimeric Species 204
Table 4. Selected Geometries in Å for the Dimeric Species 205
PART Ⅱ. Incorporation of Transition Metal Ion to Homogeneous and Heterogeneous Catalysts to Improve Their Reactivities 231
Chapter Ⅰ. High-Voltage Symmetric Nonaqueous Redox Flow Battery Based on Modularly Tunable Trimetallic Coordination Cluster Compounds with Multielectron Storage Capability 231
Table 1. Diffusion Coefficient of Each Redox Event for All Ru₂M Complexes(M=Ru, Co, Ni, Mn, Zn) 231
Chapter Ⅱ. W-O Bond Shortening by Doping of First-Row Transition Metal Ions on WO₃ NPs That Enhances Theirs Catalytic Potency 279
Table 1. Structural Parameters from EXAFS Fits 279
Chapter Ⅲ. Selective Oxidation of Biomass Molecules by Modified ZnO Nanoparticles via Charge Mismatch with Doped Co Ions 307
Table 1. Structural Parameters from EXAFS Fits for the Pristine ZnO, Co³⁺@ZnO, and Co²⁺@ZnO NPs 307
Table 2. Photocatalytic Degradation Properties of the Three Samples, as Determined by the Degradation of HMF for 36 h at 365 nm Wavelength, respectively 309
PART Ⅰ. Synthesis, Characterization, and Reactivity Studies of Novel Homogeneous Transition Metal Catalysts 51
Chapter Ⅰ. Metal Ion-Coupled Electron Transfer Reactivities on a Series of Unprecedented Mononuclear Nonheme Cobalt(III)-Iodosylbenzene Complexes 51
Figure 1. (a) X-band EPR spectra of 1 (1.0 mM, black) and 2 (1.0 mM, red) recorded in CH₃CN at 5 K. (b) ESI MS spectrum of 1 in CH₃CN. A prominent... 51
Figure 2. Crystal structure of [Co(HN3O2)(H₂O)](H₂O)(ClO₄)₂ (1), with thermal ellipsoids showing 50% probability. Perchlorate ions, uncoordinated... 52
Figure 3. (a) UV-vis spectra of 2 (1.0 mM, red line) formed in the reaction of 1 (1.0 mM, black line) and PhIO (3.0 mM) in CH₃CN at 293 K. Inset shows... 56
Figure 4. (a) ¹H NMR spectra of [Co(HN3O2)]²⁺ (black), [Co(HN3O2)]²⁺ in the presence of 2.0 equiv of PhIO (blue), and [Co(HN3O2)]²⁺ in the... 57
Figure 5. (a) Normalized Co K-edge XANES spectra of 1 (black line) and 2 (red line). Inset shows pre-edge region. (b) Fourier-transform of k³-... 58
Figure 6. (a) UV-vis spectral changes of 2 (1.0 mM, black line) to 2-Sc (1.0 mM, red line) upon addition of Sc(OTf)₃ to 2 in increments of 0.2 equiv... 60
Figure 7. CSI MS spectrum of 2-Y in CH₃CN. A prominent peak at m/z of 954.9, whose mass and isotopic distribution pattern correspond to... 62
Figure 8. rRaman spectra of 2-Al (22.0 mM, blue), 2-Y (22.0 mM, orange), and 2-Zn (22.0 mM, green) in CH₃CN at –40 ℃ upon 532 nm-excitation... 64
Figure 9. (a) Normalized Co K-edge XANES spectra of 2-M (M =Sc³⁺ (red line), Al³⁺ (blue line), Y³⁺ (orange line), and Zn²⁺ (green line)). (b)... 65
Figure 10. (a) Fourier-transform of k³-weighted EXAFS spectrum of 2 (black) with the best fit (red). Inset shows k³-weighted EXAFS spectrum... 66
Figure 11. DFT-optimized structures of (a) 2-Zn, (b) 2-Y, (c) 2-Al, and (d) 2-Sc with bond distance obtained from DFT calculation (black) and... 69
Figure 12. (a) UV-vis spectral changes observed in the electron transfer reaction from Me₂Fc (1.25 mM) to 2 (0.25 mM) in CH₃CN at 20 ℃. The... 71
Figure 13. ESI MS spectrum obtained after the reaction between 2 and ferrocene. A prominent peak at m/z of 186.1 is assignable to ferroceniumcation. 72
Figure 14. Cyclic voltammograms of 2 (2.0 mM) in CH₃CN containing TBAPF₆ (0.10 M) with a glassy carbon working electrode at 20 ℃. Scan... 73
Figure 15. Plots of pseudo-first-order rate constants (kobs) against the concentrations of (a) BrFc, (b) Fc, (c) Me₂Fc (d) Me₁₀Fc to determine the...[이미지참조] 76
Figure 16. Driving force (−△Gₑₜ) dependence of the logarithm of the rate constants (log kₑₜ) of ET from one-electron donors to 2-Sc (red dots), 2-... 77
Figure 17. (a) UV-vis spectral changes observed in the electron transfer reaction from TBPA (5.0 mM) to 2-Sc (0.25 mM) in CH₃CN at 20 ℃. The... 79
Figure 18. Cyclic voltammograms of 2-Sc (2.0 mM, red), 2-Al (2.0 mM, blue), 2-Y (2.0 mM, orange), and 2-Zn (2.0 mM, green) in CH₃CN... 80
Figure 19. (a) Plot of concentration of [TBPA·⁺] produced in electron transfer reaction from TBPA to 2-Al vs. initial concentration of TBPA,...[이미지참조] 81
Figure 20. Plots of pseudo-first-order rate constants (kobs) against the concentrations of (a) TBPA, (b) TPA, (c) 4-Br-DMA (d) DMA to...[이미지참조] 82
Figure 21. Plots of pseudo-first-order rate constants (kobs) against the concentrations of (a) TBPA, (b) TPA, (c) 4-Br-DMA (d) DMA (e) 4-Me-...[이미지참조] 83
Figure 22. UV-vis absorption spectral changes observed in the electron transfer reaction from DMA (9.0 mM) to 2-Y (0.25 mM) in CH₃CN at 20 ℃.... 85
Figure 23. Plots of pseudo-first-order rate constants (kobs) against the concentrations of (a) TPA, (b) 4-Br-DMA, (c) DMA (d) 4-Me-DMA to...[이미지참조] 86
Figure 24. Plots of pseudo-first-order rate constants (kobs) against the concentrations of (a) Br₂Fc, (b) BrFc, (c) Fc (d) Me₂Fc to determine the k₂...[이미지참조] 87
Figure 25. (a) Plot of concentration of [4-Br-DMA·⁺] produced in electron transfer reaction from 4-Br-DMA to 2-Y vs. initial concentration of 4-...[이미지참조] 88
Figure 26. (a) Plot of concentration of [4-Br-DMA·⁺] produced in electron transfer reaction from 4-Br-DMA to 2-Zn vs. initial concentration of 4-...[이미지참조] 89
Chapter Ⅱ. Synthesis, Characterization and Catalytic Activity of a Mononuclear Nonheme Copper(II)-Iodosylbenzene Adduct 105
Figure 1. (a) UV-vis spectra obtained in the reaction of 1 (0.10 mM) with iodosylbenzene (0.30 mM) in CH₃CN at 293 K. Inset shows the visible... 105
Figure 2. X-band EPR of a frozen CH₃CN-solution of 1 at 4 K. 106
Figure 3. DFT optimized structures of 1 without (left) and with H-bonding interaction (right) between HN3O2 ligand and iodosylbenzene moiety.... 108
Figure 4. TD-DFT simulated absorption spectra of (a) 1a and (b) 1b. 109
Figure 5. (a) Cyclic voltammogram of 1 (2.0 mM) in CH₃CN containing TBAPF₆ (0.10 M) with a glassy carbon working electrode at various scan... 111
Figure 6. (a) UV-vis spectral changes observed in the electron transfer reaction from Me₂Fc to 1 in CH₃CN at 293 K. Inset showe the time course... 112
Figure 7. Plot of concentrations of methyl phenyl sulfoxide (black dot), methyl phenyl sulfone (blue dot) and turnover number (red dot) obtained in... 114
Figure 8. (a) Plot of turnover number (TON) obtained in the catalytic sulfoxidation reaction of thioanisole (10 mM) with [CuII(HN3O2)(CH₃CN)...[이미지참조] 116
Chapter Ⅲ. An End-on Bis(µ-Hydroxo) Dimanganese(II,III) Azide Complex for C-H Bond and O-H Bond Activation Reactions 131
Figure 1. (a) ESI-MS spectrum of [Mn(HN3O2)(ClO₄)](ClO₄) in CH₃CN at 20 ℃. A prominent peak at m/z of 441.1 corresponds to mass and isotope... 131
Figure 2. X-ray crystal structures of (a) mono- and (b) dinuclear mananese complexes, [Mn(HN3O2)(ClO₄)]⁺, and [Mn₂(HN3O2)₂(N₃)₄]⁺... 132
Figure 3. (a) ESI-MS spectrum of 1 in CH₃CN at 20 ℃. A prominent peak at m/z of 724.2 corresponds to mass and isotope distribution pattern of... 136
Figure 4. Paramagnetic ¹H NMR spectrum of 1 in CD₃CN at 20 ℃. 137
Figure 5. ATR-IR spectra of the isolated 1 collected from the reaction between [Mn(HN3O2)(ClO₄)](ClO₄) (12 mM) and 2.2 equiv of NaN₃ in... 138
Figure 6. UV-vis spectral change observed in the reaction of 1 (0.25mM) and cumylhydroperoxide (0.40 mM) in CH₃CN at 20 ℃. 140
Figure 7. (a) ESI-MS spectrum of 2 obtained in CH₃CN at 20 ℃. A prominent peak at m/z of 799.8 corresponds to [Mn₂(HN3O2)(N3O2)(OH)₂... 141
Figure 8. UV-vis spectral change observed in the reaction between 2 (0.25mM) and ferrocene (5.0 mM) in CH₃CN at 20 ℃. The appearance of... 142
Figure 9. ATR-IR spectra of the isolated 2 collected from the reaction between 1 (12 mM) and 4.0 equiv of peracetic acid in CH₃CN at 20 ℃. The... 143
Figure 10. Paramagnetic ¹H NMR spectrum of 2 in CD₃CN at 20 ℃ 144
Figure 11. Plot of pseudo-first-order rate constants (kobs) against the concentration of substrates [(a) BNAH, (b) xanthene, (c) 9,10-...[이미지참조] 150
Figure 12. (a) ESI-MS spectrum obtained after the completion of the C-H bond activation of xanthene (1.0 mM) by 2 (0.10 mM) in CH₃CN at 20 ℃.... 151
Figure 13. Plots of kobs against concentrations of xanthene (black) and xanthene-d₂ (red) in order to determine k₂ in the C-H bond activation by... 152
Figure 14. (a) UV-vis spectral changes observed in the reaction of 2 (0.25mM) and xanthene (25.0 mM) in CH₃CN at 20 ℃. Inset shows the time... 153
Figure 15. DFT-optimized structures of (a) the MnII-OH bond breaking TS(TS1). All Mn-OH bond lengths are shown for comparison. (b) The C-H...[이미지참조] 156
Figure 16. (a) UV-vis spectral changes observed in the reaction of 2 (0.25mM) and DTBP (5.0 mM) in CH₃CN at 20 ℃. The increase of absorption... 159
Figure 17. Plot of pseudo-first-order rate constants (kobs) against the concentration of p-X-DTBP (X = OMe, tBu, Et, Me, H) in order to...[이미지참조] 161
Figure 18. (a) Plot of RT/F ln k₂ against Eₒₓ of p-X-DTBP for the O–H bond activation reaction by 2 in CH₃CN at 20 ℃. (b) Plot of log k₂ against BDE of... 162
Chapter Ⅳ. Mono - and Dinuclear Zinc Complexes Bearing Identical Bis(Thiosemicarbazone) Ligand That Exhibit Alkaline Phosphatase-Like Catalytic Reactivity 174
Figure 1. (a) UV-vis spectra obtained in the reaction of 1 (black line, 2.0X10⁻² mM) with 4-NPP (red line, 1.0 X 10⁻¹ mM) in DMSO at 40 ℃. The... 174
Figure 2. Negative mode ESI MS spectrum obtained in the reaction of 1(0.020 mM) with 4-NPP in DMSO at 40 ℃. A prominent peak at m/z of... 175
Figure 3. UV-vis spectra of the reaction of 1 (black line, 2.0 X 10⁻² mM) with 4-NPP (blue line, 2.0 X 10⁻¹ mM) in (a) CH₃CN and (b) CH₃OH at 40... 177
Figure 4. UV-vis spectral changes obtained in the reaction of 1 (black line, 2.0 X 10⁻² mM) with 4-NPP (blue line, 2.0 X 10⁻¹ mM) in DMF at 40 ℃.... 178
Figure 5. Two conformations for 1 in DMSO. Left, 1A; right, 1B.[이미지참조] 179
Figure 6. UV-vis absortion spectra simulation with TDDFT of conformers 1A and 1B. Left, experimental data from Figure 22 presented as comparison...[이미지참조] 180
Figure 7. Deprotonation of water molecule coordinated to Zn. DFT-optimized transition state structure of [Zn(bTSC)(PO₄C₆H₄NO₂)₂(H₂O]²⁻.... 183
Figure 8. DFT-optimized transition state structure in the deprotonation reaction of water molecule coordinated to Zn by an external 4-NPP, shuttled... 184
Figure 9. DFT-optimized (a) reactant structure of [Zn(bTSC)(PO₄C₆H₄NO₂)(OH)]⁻ (with DMSO as a spectator molecule), (b) the transition state... 185
Figure 10. UV-vis spectral changes showing the formation of 2 (red line, 2.0 X 10⁻² mM) and disappearance of 1 (black line, 1.0 X 10⁻² mM) upon... 188
Figure 11. Spectrophotometric titration of 1 (black dot, 0.10 mM) and 2 (red dot) in a H₂O/DMSO solution (1:1) over a pH range from 6 to 12. 189
Figure 12. (a) UV-vis spectra obtained in the reaction of 2 (black line, 5.0 X 10⁻³ mM) with 4-NPP (1.0 X 10⁻¹ mM) in the presence of KOH (1.1... 191
Figure 13. Overlayed UV-vis spectra of 4-NPP (black line, 1.0 X 10⁻¹ mM) in the presence of KOH (red line, 1.1 X 10⁻² mM) in DMSO at 40 ℃.... 192
Figure 14. Plot of pseudo-first-order rate constants (kobs) against the concentrations of KOH to determine the k₂ value for 2 in DMSO at 40 ℃.[이미지참조] 193
Figure 15. Dependence of the hydrolysis reaction rates on the concentration of NPP for 1 (red dot) and 2 (blue dot) in DMSO at 40 ℃. 197
Figure 16. Three conformations for 2 in DMSO. Left, 2A; middle, 2B; right, 2C. Hydrogens omitted for clarity.[이미지참조] 198
Figure 17. UV-vis absortion spectra simulation with TDDFT of conformers 2A, 2B, and 2C. Left, experimental data from Fig. S15 is presented as...[이미지참조] 200
Figure 18. Occupied NTO with the highest contribution to the lowest energy electronic transition of 2B (left) and 2C (right). Hydrogens are omitted for clarity.[이미지참조] 201
Figure 19. DFT-optimized structures of (a) [Zn₂(bTSC)₂ (PO₄C₆H₅)(OH)], and (b) [Zn(bTSC)(HPO₄)]. Zn, silver; S, yellow; N, blue; O, red; P, purple;... 202
Figure 20. Alternative structures of 2 found using DFT. Zn, dark red; S, yellow; N, blue; O, red; P, orange; C, gray; H, white. Hydrogens are omitted... 203
Figure 21. UV-vis spectral changes obtained in the reaction of 2 (black line, 1.0 X 10⁻⁴ mM) with 4-NPP (1.0 X 10⁻¹ mM) in the presence of KOH... 207
Figure 22. UV-vis spectral changes showing the conversion from 1 (black line, 1.0 X 10⁻² mM) to 2 (red line, 1.0 X 10⁻² mM) upon addition of KOH... 208
PART Ⅱ. Incorporation of Transition Metal Ion to Homogeneous and Heterogeneous Catalyst to Improve Their Reactivities 217
Chapter Ⅰ. High - Voltage Symmetric Nonaqueous Redox Flow Battery Based on Modularly Tunable Trimetallic Coordination Cluster Compounds with Multielectron Storage Capability 217
Figure 1. (a) Structure of [Ru₃(μ₃-O)(CH₃COO)₆(py)₃]⁺ with modularly tunable handles: (1) transition metal, (2) bridging ligands, and (3)... 217
Figure 2. (a) Cyclic voltammogram of [Ru₃(μ₃-O)(CH₃COO)₆(py)₃](PF₆). Four discrete redox events are numbered for reference in the main text... 218
Figure 3. ESI MS spectrum of (a) [Ru₃(μ₃-O)(CH₃COO)₆(py)₃]⁺, (b) [Ru₃(μ₃-O)(CH₃CH₂COO)₆(py)₃]⁺, (c) [Ru₃(μ₃-O)(CH₃COO)₆(Mepy)₃]⁺,... 222
Figure 4. ESI MS spectrum of (a) [Ru₂Mn(μ₃-O)(CH₃COO)₆(py)₃]⁺, (b) [Ru₂Co(μ₃-O)(CH₃COO)₆(py)₃]⁺, (c) [Ru2Ni(μ₃-O)(CH₃COO)₆(py)₃]⁺, and... 223
Figure 5. (a) Charge-discharge profile of the redox flow cell cycle #3 to cycle #8. (b) Enlarged graph of cycle #5. (c) Efficiency vs. cycle number... 228
Figure 6. CVs of (a) [Ru₃(μ₃-O)(CH₃COO)₆(py)₃]⁺ (Ru) (b) [Ru₂Co(μ₃-O)(CH₃COO)₆(py)₃] (Co) in various scan rates (10, 20, 50, 100, 200 mV/s).... 229
Figure 7. CVs of (a) [Ru₂Ni(μ₃-O)(CH₃COO)₆(py)₃] (Ni), (b) [Ru₂Mn(μ₃-O)(CH₃COO)₆(py)₃] (Mn) and (c) [Ru2Zn(μ₃-O)(CH₃COO)₆(py)₃] (Zn) in... 230
Figure 8. (a) Visualization of the HOMOs of each redox states of [Ru₃(μ₃-O)(CH₃COO)₆(py)₃]⁺. The orbitals with isosurface value of 0.02... 233
Figure 9. Changes of CVs for [Ru₃(μ₃-O)(CH₃COO)₆(py)₃]⁺ at the presence of oxygen and water. Oxygen reduction reaction occurs when the applied... 235
Figure 10. Charge-discharge profile of the symmetric 2e⁻ [Ru₃(μ₃-O)(CH₃COO)₆(py)₃]⁺ battery cell using 3 redox events during 40 h. 236
Figure 11. Efficiencies and capacity changes of the symmetric 2e⁻ [Ru₃(μ₃-O)(CH₃COO)₆(py)₃]⁺ battery cell using 3 redox events. 237
Figure 12. Cyclic voltammograms of 1.0 mM [Ru₃(μ₃-O)(CH₃COO)₆(py)₃](PF₆) and [Ru₃(μ₃-O)(CH₃CH₂COO)₆(py)₃](PF₆) in acetonitrile.... 239
Figure 13. (a) UV-vis spectra of [Ru₃(μ₃-O)(CH₃COO)₆(py)₃]⁺in various concentrations. (b) Calibration graph of UV-vis spectra. Diluted solution of... 240
Figure 14. (a) UV-vis spectra of [Ru₃(μ₃-O)(CH₃CH₂COO)₆(py)₃]⁺ in various concentrations. (b) Calibration graph of UV-vis spectra. Diluted... 241
Figure 15. Capacity vs. cycle number profile for symmetric battery cycle of [Ru₃(μ₃-O)(CH₃CH₂COO)₆(py)₃]⁺. The improved solubility of [Ru₃(μ₃-O)... 242
Figure 16. (a) UV-vis spectra of [Ru₃(μ₃-O)(CH₃COO)₆(Mepy)₃]⁺ in various concentrations. (b) Calibration graph of UV-vis spectra. Diluted by... 243
Figure 17. (a) UV-vis spectra of [Ru₃(μ₃-O)(CH₃COO)₆(OMepy)₃]⁺ in various concentrations. (b) Calibration graph of UV-vis spectra. Diluted by... 244
Figure 18. (a) UV-vis spectra of [Ru₃(μ₃-O)(OAc)₆(NH₂py)₃]⁺ in various concentrations. (b) Calibration graph of UV-vis spectra. Diluted by one-... 245
Figure 19. Cyclic voltammograms of 1.0 mM [Ru₃(μ₃-O)(CH₃COO)₆(Mepy)₃](PF₆) and 50 mM [Ru₃(μ₃-O)(CH₃COO)₆(Mepy)₃](PF₆) in... 246
Figure 20. (a) Cyclic voltammograms of the Ru₂M(μ₃-O)(CH₃COO)₆(py)₃(M = Ru, Co, Ni, Mn, Zn). Redox peaks appear in dashed-line boxes were... 247
Figure 21. (a) Cyclic voltammograms of [Ru₃(μ₃-O)(CH₃COO)₆(py-R)₃]⁺ (-R = -H, -Me, -OMe, -NH₂). (b) Enlargement of (a) into potential range... 250
Chapter Ⅱ. W-O Bond Shortening by Doping of First-Row Transition Metal Ions on WO₃ NPs That Enhances Their s Catalytic Potency 264
Figure 1. (a) X-ray diffraction patterns and (b) Raman spectra of pristine WO₃ (black line), Cr@WO₃ (red line), Mn@WO₃ (orange line), Fe@WO₃... 264
Figure 2. TEM images of (a) pristine WO₃, (b) Cr@WO₃, (c) Mn@WO₃, (d) Fe@WO₃, (e) Co@WO₃, and (f) Ni@WO₃. 266
Figure 3. EDX analysis of Cr@WO₃ NPs. 267
Figure 4. EDX analysis of Mn@WO₃ NPs. 268
Figure 5. EDX analysis of Fe@WO₃ NPs. 269
Figure 6. EDX analysis of Co@WO₃ NPs. 270
Figure 7. EDX analysis of Ni@WO₃ NPs. 271
Figure 8. XPS spectra of W 4f for TM ions doped WO₃ NPs: pristine WO₃, Cr@WO₃, Mn@WO₃, Fe@WO₃, Co@WO₃, and Ni@WO₃ NPs (from bottom to top). 272
Figure 9. (a) XPS spectra of O 1s core level for TM ions doped WO₃ NPs: pristine WO₃, Cr@WO₃, Mn@WO₃, Fe@WO₃, Co@WO₃, and Ni@WO₃ NPs... 273
Figure 10. (a) Overlaid W L₃-edge XANES data and (b) second derivatives for WO₃ (black line), and TM@ WO₃ (TM = Cr (red line), Mn (blue line),... 276
Figure 11. EXAFS fitting of (a) pristine WO₃, (b) Cr@WO₃, (c) Mn@WO₃, (d) Fe@WO₃, (e) Co@WO₃, and (f) Ni@WO₃. 278
Figure 12. (a) Photocatalytic degradation of TM ion doped WO₃ NPs:pristine WO₃, Cr@WO₃, Mn@WO₃, Fe@WO₃, Co@WO₃, and Ni@WO₃ NPs.... 281
Figure 13. UV-vis spectra of WO₃-based electrocatalysts doped with (b) Cr, (c) Mn, (d) Fe, (e) Co, and (f) Ni ((a) is that of an undoped sample)... 283
Figure 14. A representative UV-vis spectra of WO₃-based catalyst sample before HER (black trace), after HER (red trace), and after re-oxidation... 285
Figure 15. Stability test for WO₃-based catalysts in their HER by chronoamperometry. Cr@WO₃ exhibited ca. 50% activity loss, however, all... 286
Chapter Ⅲ. Selective Oxidation of Biomass Molecules by Modified ZnO Nanoparticles via Charge Mismatch with Doped Co Ions 298
Figure 1. HAADF-STEM images of (a) ZnO, (b) Co³⁺@ZnO, and (c) Co²⁺@ZnO NPs. These high magnification images show the overall... 298
Figure 2. TEM-EDS images of (a) ZnO, (b) Co³⁺@ZnO, and (c) Co²⁺@ZnO NPs. The scale bar is 100 nm. 300
Figure 3. (a) XRD, (b) DRS spectra, (c) XPS (Zn 2p and O 1s core-level spectra), and (d) EPR spectra of three ZnO NPs (black: ZnO, orange:... 301
Figure 4. XAS spectra of three ZnO NPs; (a) Zn L-edge, (b) O K-edge, and (c) Co L-edge. (d) Normalized Zn K-edge XANES spectra and (e)... 303
Figure 5. Zn-K-edge EXAFS fitting plots for (a) pristine ZnO NPs, (b) Co³⁺@ZnO NPs, and (c) Co²⁺@ZnO NPs. All fits performed in R-space 306
Figure 6. PCD properties of (a) HMF among three ZnO NPs with or without DMPO (radical scavenger) and product analysis through LC-MS spectra: (b)... 308
Figure 7. Repeated cycles of HMF degradation with three tested ZnO NPs under 365 nm irradiation (the catalysts were recovered at the end of each... 310