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研究生： 吳昱葶
Wu, Yu-Ting
論文名稱： 具推電子取代基的雙分子鈷錯合物之電化學水氧化研究
Electrochemical Water Oxidation Catalyzed by Dinuclear Cobalt Complexes with Electron Donating Substituents
指導教授： 王育恒
Wang, Yu-Heng
口試委員: 楊自雄
Yang , Tzu-Hsiung
周憲辛
Chou, Hsien-Hsin
朱見和
Chu, Jean-Ho
學位類別： 碩士
Master
系所名稱： 理學院 - 化學系
Department of Chemistry
論文出版年： 2023
畢業學年度： 111
語文別： 英文
論文頁數： 296
中文關鍵詞： 電化學 、均相水氧化 、分子電催化劑 、推電子基 、過電位 、轉換率 、線性自由能關係
外文關鍵詞： electrochemistry, homogeneous water oxidation, molecular electrocatalyst, electro-donating group, overpotential, turnover frequency, linear free energy relationship (LFER
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    • 水分解擁有將水分解為質子和氧氣的巨大潛力，用於能量的儲存和轉換。高效的水氧化催化劑（WOCs）在此過程中扮演著重要角色。然而，稀有的過渡金屬催化劑成本高昂且稀少限制了其可擴展性。為了解決這問題，探索成本效益更高的替代方案，如第一周期過渡金屬，使催化劑進一步的研究將推動能量轉換的發展。本論文的第二章主要探討具有推電子基團取代bisbenzimidazolepyrazolide配位基的雙分子鈷錯合物(1-4)在均相催化的水氧化反應。研究旨在利用電子效應和配位基的非無辜性質來調節催化電位和催化活性。值得注意的是，3帶有非無辜的配位基(-OCH3, H2L3)表現出顯著較低的氧化還原電位，突顯了推電子取代基的影響。動力學研究揭示了錯合物3與錯合物1之間的不同行為，揭示了水氧化催化的複雜性並促使進一步的機理研究。此外，通過建立線性自由能關係（LFER），進一步闡明了這些雙分子鈷錯合物的催化行為。通過修飾非無辜配體，可以有效調節水氧化催化劑的氧化還原電位，降低所需過電位。雖然這些修飾並未提高催化活性，但這項研究在高效水氧化催化劑的設計方面取得了重大進展，凸顯了利用氧化還原非無辜配體來設計分子催化劑，用於各種與能源相關的反應，包括水氧化反應，以提高其在動力學和熱力學方面的催化性能的潛力。整體而言，這項研究有助於理解和開發高效的水氧化催化劑，促進能源轉換的進步，並為可持續能源利用提供有希望的途徑。

    Water splitting holds great potential for energy storage and conversion by breaking down water into protons and oxygen. Efficient water oxidation catalysts (WOCs) play a crucial role in this process. While rare transition metal catalysts have shown promise, their high cost and limited availability hinder scalability. To address this challenge, researchers are exploring cost-effective alternatives, such as first-row transition metals. Further investigation of these catalysts can advance energy conversion and contribute to addressing the global energy crisis.
    Chapter 2 of this thesis focuses on the investigation of homogeneous 4e−/4H+ water oxidation catalysis and explores analog dinuclear cobalt complexes (1–4) with bisbenzimidazolepyrazolide-type ligands containing electron-donating group (EDG) substituents. The study focuses on harnessing electronic effects and exploiting the non-innocent nature of ligands to modulate catalytic potential and reactivity. Notably, complex 3 with a non-innocent ligand featuring methoxy substituents (H2L3) exhibits a significantly lower redox potential, highlighting the effect of electron-donating substituents. The kinetic studies shed light on the different behavior of complex 3 compared to complex 1, revealing the intricacies of water oxidation catalysis and prompting further mechanistic investigations. Additionally, the establishment of a linear free energy relationship (LFER) further elucidates the catalytic behavior of these dinuclear cobalt complexes. By modifying non-innocent ligands, the oxidation-reduction potential of water oxidation catalysts can be effectively adjusted, reducing the required overpotential. Although the modifications did not enhance catalytic activity, this research represents a significant advancement in the engineering of efficient water oxidation catalysts. Furthermore, it highlights the potential of using redox non-innocent ligands to engineer molecular catalysts for various energy-related reactions, including water oxidation, to enhance their catalytic performance in terms of kinetics and thermodynamics.
    Overall, this investigation contributes to the understanding and development of efficient water oxidation catalysts, supporting advancements in energy conversion and offering promising avenues for sustainable energy utilization.

    Abstract i 摘要 iii 謝誌 iv Table of Contents v List of Figures ix List of Schemes xxi List of Tables xxii Abbreviations and Acronyms xxv Chapter 1. Water Oxidation Reaction: Introduction and Background 1 1.1. Addressing the Global Environmental Challenges and Energy Crisis 2 1.2. Unveiling the Secrets of Natural Photosynthesis 2 1.3. Innovating Artificial Photosynthesis (AP) 5 1.4. Obstacles in Water Oxidation: Addressing the Challenges 7 1.5. Molecular Water Oxidation Catalysts (MWOCs) 7 1.6. Evaluation of Water Oxidation Catalysts (WOCs) 8 1.6.1. Definition of TOF for MWOCs 9 1.6.2. Definition of η for MWOCs 11 1.7. Linear free energy relationships between rate and overpotential 13 1.8. How non-innocent Ligands Effect Water Oxidation. 14 1.9. Thesis scope 15 1.10. References 17 Chapter 2. Electrochemical Water Oxidation Catalyzed by Dinuclear Cobalt Complexes with Electron Donating Substituents 23 2.1. Abstract 24 2.2. Introduction 25 2.2.1. Homogeneous Dinuclear Ru-based Complexes for Water Oxidation 26 2.2.2. Homogeneous Dinuclear Co-based Complexes for Water Oxidation 27 2.3. Results and Discussion 31 2.3.1. Synthesis and Characterization of Dinuclear Cobalt Complexes 1–4 31 2.3.2. Electrochemical Properties of Cobalt Complex 1–4 34 2.3.3. Electrocatalysis for Water Oxidation of Complex 2 and 3 40 2.3.4. Evidence for homogeneity Studies for of Complex 2 and 3 41 2.3.5. Kinetic analysis 44 2.3.6. Investigation of Reaction Intermediates and Analysis of Catalyst Resting State 49 2.3.7. SEC Analysis under Non-catalytic Alkaline Conditions 49 2.3.8. SEC Analysis under Catalytic Conditions 51 2.3.9. NMR Spectroscopic Experiments 52 2.3.10. CSI-MS 55 2.3.11. EPR Spectroscopic Experiments 58 2.3.12. log(TOFmax)–η analysis 60 2.4. Conclusions 62 2.5. Acknowledgements 63 2.6. Author Contributions 64 Supp Info Chapter 3. 67 1. General Experimental Considerations 67 2. Synthesis of Precursors, Ligands and Cobalt Complexes 68 2a. Synthesis of Precursors 68 2b. Synthesis of Ligands. 72 2c. Synthesis of Dinuclear Cobalt Complexes. 74 3. UV-Vis Spectral Measurements 77 3a. General considerations 77 3b. UV-Vis absorption spectra of Co complexes 77 3c. UV-Vis absorption spectra of ligands 79 3d. Stability test 80 4. Electrochemical Experiments 82 4a. General considerations 82 4b. Redox Properties of Co complexes in anhydrous MeCN 83 4c. Differential pulse voltammograms of Co complexes in anhydrous MeCN 85 4d. Scan-rate effects on WO by Co complexes 86 4e. Diffusion coefficient of Co complexes 88 5. Supporting Evidence for a Homogeneous Electrocatalyst 91 5a. Consecutive CV scans 91 5b. Rinse test 92 5c. Characterization of electrodes after consecutive CV scans 95 5d. Stability test 99 6. Controlled Potential Electrolysis (CPE) Experiments 101 6a. General considerations 101 6b. Oxygen evolution 101 6c. Selectivity of water oxidation by cobalt complexes. 105 7. Rate Law Analysis of H2O Oxidation Catalyzed by Co complexes 107 7a. General considerations 108 7b. [Co]-dependence 108 7c. [H2O]-dependence 110 8. Kinetic Isotope Effects (KIE) 111 8a. General considerations 111 8b. Cyclic voltammograms analysis of Co complexes in H2O or D2O 111 9. Determining Turnover Frequency (TOF) through Cyclic Voltammetry Measurements 113 9a. General procedure 113 10. Estimation of the Thermodynamic Reduction Potential of O2/H2O at Non-standard state. ..............................................................................................................................117 10a. Open-circuit potential (OCP) measurement for EH+/H2 in MeCN 117 10b. Estimation of EO2/H2O based on OCP measurements of EH+/H2 118 10c. Derivation of overpotential (η) 119 11. Spectroelectrochemical Study 120 11a. General considerations 120 11b. Spectroelectrochemical studies of Co intermediates under non-catalytic condition.............................................................................................................................. 120 11c. Spectroelectrochemical studies of Co intermediates under non-catalytic condition ............................................................................................................................... 121 12. NMR Spectroscopic Experiments 123 12a. General considerations 123 13. Cold-spray ionization mass spectrometry (CSI-MS) 125 14. EPR Spectroscopic Experiments 125 14a. General considerations 125 15. Compound Spectra 128 16. Crystallographic Data 169 16a. Single crystal X-ray crystallography for 2. 169 16b. Single crystal X-ray crystallography for 3. 180 16c. Single crystal X-ray crystallography for 4. 193 16d. Single crystal X-ray crystallography for 1+. 208 16e. Single crystal X-ray crystallography for 3+. 218 17. References 230 Appendix 1. Appendix to Chapter 2 233 A1.1. General Experimental Considerations 234 A1.2. Synthesis of Precursors, Ligands, Cobalt Complexes and Oxidants 235 A1.2a. Synthesis of Precursors 235 A1.2b. Synthesis of Ligands 238 A1.2c. Synthesis of Dinuclear Cobalt Complexes 240 A1.2d. Synthesis of Oxidants 241 A1.3. Compound Spectra 243 A1.4. Crystallographic Data 267 A1.4a. Single crystal X-ray crystallography for C1. 267 A1.4b. Single crystal X-ray crystallography for C2. 275 A1.4c. Single crystal X-ray crystallography for P7. 294 A1.4d. Single crystal X-ray crystallography for P9’. 294 A1.5. References 294   List of Figures Figure1.1. Schematic representation of photosynthetic electron transport chain. Photosystem I (PSI), Photosystem II (PSII), Cytochrome b6f complex (Cyt b6f), Plastocyanin (PC), Ferredoxin (Fd) and ferredoxin-NADP reductase (FNR). Cytochrome c6 (Cyt c6) transfers electrons from the Cyt b6f. 3 Figure1.2. Structure of the Mn4CaO5 cluster of the OEC in PSII. Reprinted with permission from ref. 11 Copyright 2019 The Royal Society of Chemistry. (b) The Kok Cycle illustrates the stepwise process of photosynthetic water oxidation by the Mn4CaO5 cluster in PSII. Reprinted with permission from ref. 10 Copyright 2023 Springer. 5 Figure1.3. Schematic representation of a tandem photoelectrochemical cell. Reprinted with permission from ref. 18 Copyright 2016 American Association for the Advancement of Science. 6 Figure1. 4. Comparing natural enzymes and artificial ruthenium-based catalysts for water oxidation: features and development approach for efficient molecular catalysts with earth-abundant metals Reprinted with permission from ref. 12 Copyright 2021 Royal Society of Chemistry. 8 Figure1.5. Schematic representation CV responses associated with different catalytic potentials and overpotentials. The catalytic CVs are given under catalytic conditions (blue and green traces), and the non-catalytic CVs are due to the single-electron transfer of catalysts under non-catalytic conditions (black traces). Reprinted with permission from ref. 22 Copyright 2022 Wiley-VCH. 12 Figure1.6. Catalyst Performance Evaluation: Unveiling the Log(TOF)−η Relationship. Adapted from ref. 37 with permission. Copyright 2020, The Royal Society of Chemistry 2020. 13 Figure1.7. General representation of four main strategies of using redox non-innocent ligands in catalysis. Reprinted with permission from ref. 38. Copyright 2012 American Chemical Society. 15 Figure 2.1. Previously reported representative Ru-based polypyridine complexes 27 Figure 2.2. Previously reported representative Co-based polypyridine complexes. 28 Figure 2.3. ORTEP drawings of (a) 2, (b) 3 and (c) 4 with thermal ellipsoids at 50%, 30% and 30% probability, respectively. Hydrogen atoms and counterions (PF6−) are omitted for clarity (see Section 17 in the Supporting Information). 33 Figure 2.4. CVs of 0.4 mM Co complexes 2 (a) in the absence/presence of 40 mM NaOH, 3 (b) and 4 (c) in the absence/presence of 10 mM NaOH with 15-crown-5 in anhydrous MeCN. All CVs were recorded under 1 atm N2 at the scan rate of 100 mVs−1 (for 2), 25 mVs−1 (for 3) and 10 mVs−1 (for 4). Solid trace: 0.4 mM Co complex in the absence/presence of NaOH in anhydrous MeCN; dashed trace: blank with no complex in the absence/presence of NaOH in anhydrous MeCN. 35 Figure 2.5. CVs (a) and DPV (b) of 2 in the presence of NaOH (0–40mM) in anhydrous MeCN. All CVs were recorded under 1 atm N2 at a scan rate of 100 mVs−1. Supporting electrolyte: 0.1 M [NBu4][PF6]. WE: glassy carbon (GC) disk electrode. RE: Ag+/Ag (0.01 M AgNO3/0.1 M [NBu4][PF6] in MeCN). CE: Pt wire. All DPVs were conducted with a pulse amplitude of 50 mV, a pulse period of 0.3 s, an increment of 10 mV, and a scan rate of 10 mV s−1. 36 Figure 2.6. (a) CVs of 3 in the presence of NaOH (0–40mM) in anhydrous MeCN. All CVs were recorded under 1 atm N2 at a scan rate of 100 mVs−1. Supporting electrolyte: 0.1 M [NBu4][PF6]. WE: GC disk electrode. RE: Ag+/Ag (0.01 M AgNO3/0.1 M [NBu4][PF6] in MeCN). CE: Pt wire. (b) DPV for optimized conditions of 3 in the presence of 10 mM NaOH with different equivalent 15–crown–5 (a: 6 eq, b: 16 eq) in anhydrous MeCN. All DPVs were conducted with a pulse amplitude of 50 mV, a pulse period of 0.3 s, an increment of 10 mV, and a scan rate of 10 mV s−1. 37 Figure 2.7. CVs (a) and DPV (b) of 4 in the absence/presence of 10 mM NaOH with different equivalent 15-crown-5 (a: 16 eq, b: 19 eq) in anhydrous MeCN. All CVs were recorded under 1 atm N2 at a scan rate of 100 mV s−1. Supporting electrolyte: 0.1 M [NBu4][PF6]. WE: GC disk electrode. RE: Ag+/Ag (0.01 M AgNO3/0.1 M [NBu4][PF6] in MeCN). CE: Pt wire. DPV for optimized conditions of 3 in the presence of 10 mM NaOH with different equivalent 15-crown-5 (a: 6 eq, b: 16 eq) in anhydrous MeCN. All DPVs were conducted with a pulse amplitude of 50 mV, a pulse period of 0.3 s, an increment of 10 mV, and a scan rate of 10 mV s−1. 38 Figure 2.8. CVs of 0.4 mM Co complexes 2 (a) and 3 (b) with 5 M H2O (9 %, v/v) in the presence of 0 mM (black) and 10 mM NaOH (yellow) in MeCN. (c) CVs of 0.4 mM Co complexes 2 (red) and 3 (blue) with 5 M H2O (9 %, v/v) in MeCN. The dashed traces show the CV feature of 2 and 3 in anhydrous MeCN. The gray traces show the blank controls in the absence of the catalyst. Scan rate: 100 mV s−1) Supporting electrolyte: 0.1 M [NBu4][PF6]. Working electrode (WE): GC disk electrode. Reference electrode (RE): Ag+/Ag (0.01 M AgNO3/0.1 M [NBu4][PF6] in MeCN). Counter electrode (CE): Pt wire. 40 Figure 2.9. (a) 250 consecutive CVs were recorded for 0.4mM complex 3 in the presence of 5 M H2O (9 %, v/v) in MeCN. (a) After recording the CV (red trace), the GC electrode was removed from the solution [0.4mM complex 3 with 5 M H2O (9 %, v/v)] and washed carefully with MeCN. The washed and unpolished GC electrode was then cycled in fresh 0.1 M [NBu4][PF6]/MeCN solution without catalyst (black trace). All CVs were recorded under 1 atm N2 at a scan rate of 100 mV s−1. Supporting electrolyte: 0.1 M [NBu4][PF6]. (c) Catalytic current curve obtained in CPE experiment with 0.4 mM complex 3 (blue trace) in the presence of 5 M H2O (9 %, v/v) in MeCN at 1.5 V vs. Fc+/0 over 12 h. The gray trace shows the blank control with no complex in MeCN. WE: GC disk electrode. RE: Ag+/Ag (0.01 M AgNO3/0.1 M [NBu4][PF6] in MeCN). CE: Pt wire. 42 Figure 2. 10. (a) CVs of various concentrations of 3 in the presence of 5 M H2O (9 %, v/v) in MeCN. Inset: plot of catalytic current at 1.5 V vs. [3]. (b) CVs of 0.4 mM 3 in various concentrations of H2O. Inset: plot of catalytic current at 1.5 V vs. [H2O]1/2. (c) CVs of 0.4 mM 3 in various concentrations of NaOH in the presence of 5 M H2O (9 %, v/v) in MeCN. Inset: plot of catalytic current at 1.5 V vs. [NaOH]. 46 Figure 2.11. UV–Vis SEC spectra of 3 in presence of 1 mM NBu4OH (a) at 0.40 V, (b) at 0.60 V, (c) at 1.50 V under non-catalytic conditions for 1 h. General conditions: [3] = 0.04 mM. Supporting electrolyte: 0.1 M [NBu4][PF6]. WE: Pt gauze electrode. RE: Ag+/Ag (0.01 M AgNO3/0.1 M [NBu4][PF6] in MeCN). CE: Pt wire. 50 Figure 2.12. UV–Vis SEC spectra of 3 in presence of 1 mM NBu4OH (a) at 1.50 V, 1 h (b) at 1.5 V, 3000–3600 s under catalytic conditions. (c) during the WO at 1.50 V with [H2O] = 5 M (9 % in v/v, solid black trace), compare with at 0.4 V (dash red trace), 0.6 V (dash yellow trace), and at 1.5 V (dash blue trace) under non-catalytic conditions. General conditions: [3] = 0.04 mM. Supporting electrolyte: 0.1 M [NBu4][PF6]. WE: Pt gauze electrode. RE: Ag+/Ag (0.01 M AgNO3/0.1 M [NBu4][PF6] in MeCN). CE: Pt wire. 51 Figure 2.13. NMR spectrum comparing the deprotonation state before (black) and after (red) for complex 1 (a) and complex 3 (b). ORTEP drawings of (c) 1+ and (d) 3+ with thermal ellipsoids at 50% and 50% probability, respectively. (refer to Section 12 in the Supporting Information). 53 Figure 2.14. NMR spectrum of complex 3 (red), and solvent suppression NMR spectrum during the catalytic process continuous measurement for 1 hour for complex 3. 54 Figure 2.15. (a) An initial step of the proposed catalytic cycles for 1 and 3 under alkaline conditions. (b)CSI-MS spectra of (II)-1 (m/z 913.00) and (c) (II)-3 (m/z 1033.33) were observed in MeCN at −5°C. Inset: zoom in the spectra and theoretically isotopic distribution (blue bar). NL (normalization level): base peak intensity. 56 Figure 2.16. (a) Proposed catalytic cycles for 3 under alkaline conditions. (b) CSI-MS spectra of (IV)-3 (m/z 344.50) were observed in CH3CN at −5°C. Inset: zoom in the spectra and theoretically isotopic distribution (blue bar). NL (normalization level): base peak intensity. (c) time-dependent m/z peak intensity.. 57 Figure 2.17. X-band EPR spectra of 3 (4 mM) with (a) 0.4 eq oxidant, (b) 0.4 eq oxidant in alkaline condition. 59 Figure 2. 18. (a) Log(TOFmax)–η data for dinuclear cobalt WOCs (our previous work, ○: 1, ◌: 1’ and this work, ▲: 2, ▓: 3). Log(TOFmax)–η data for dinuclear cobalt WOCs in the same conditions: (b) 5M H2O (c) 5 M H2O and 10 Mm NaOH. 61 Figure S3.1. UV-Vis absorption spectrum of Co complexes 2 (a), 3 (c) and 4 (e) in anhydrous MeCN, 2 in the presence of 10 mM NaOH (b), 3 in the presence of 10 mM NaOH (d) and 4 in the presence of 10 mM NaOH (f) in anhydrous MeCN. ……………………77 Figure S3.2. UV-Vis absorption spectrum of Co complexes in the absence (red solid)/presence (blue dash) of 10 mM NaOH in anhydrous MeCN. (a) 2, (c) 3 and (e) 4 in the range of 240–420 nm; (b) 2, (d) 3 and (f) 4 in the range of 360–720 nm. 78 Figure S3.3. UV-Vis absorption spectrum of H2L2 (a), H2L3 (c) and H2L4 (e) in anhydrous DMF, H2L2 in the presence of 10 mM NaOH (b), H2L3 in the presence of 10 mM NaOH (d) and H2L4 in the presence of 10 mM NaOH (f) in anhydrous DMF. 79 Figure S3.4. UV-Vis absorption spectra of various concentrations of Co complexes 2 (a), 3 (e) and 4 (i) in anhydrous MeCN, 2 (c), 3 (g) and 4 (k) in the presence of 10 mM NaOH in anhydrous MeCN. Plots of absorbances as a function of concentrations of Co complexes 2 (b), 3 (f) and 4 (j) in anhydrous MeCN, 2 (d), 3 (g) and 4 (l) in the presence of 10 mM NaOH in anhydrous MeCN. 81 Figure S3.5. (a) Glass vial used for voltammetry measurements. (b) Setup photograph for electrochemical experiments. 82 Figure S3.6. (a) CVs of 3 in the presence of NaOH (0–40mM) in anhydrous MeCN. (b) DPV of 3 in the presence of 0/40 mM NaOH. (c) CVs of 3 in the presence of 40 mM NaOH with different equivalent 15–crown–5 (relative to [OH−] a: 1 eq; b: 4 eq; c: 12 eq) in anhydrous MeCN. (d) DPVs of 3 in the presence of 40 mM NaOH with different equivalent 15–crown–5 (equivalent relative to [OH−] a: 1 eq; b: 4 eq; c: 12 eq) in anhydrous MeCN. 83 Figure S3.7. DPV of 3 in the presence of 0/10 mM NaOH with (a) 0–3 eq (b) 6–16 eq in anhydrous MeCN. (c) DPV of 3 in the presence of 0/10 mM NaOH with 6 and 16 eq 15–crown–5 in anhydrous MeCN. (equivalent relative to [3]) 84 Figure S3.8. DPVs of 0.4 mM Co complexes 2 (a), 3 (b) and 4 (c) in the absence/presence of 10 mM NaOH in anhydrous MeCN. Solid trace: 0.4 mM Co complex in the absence/presence of NaOH in MeCN; dashed trace: blank with no complex in the absence/presence of 10 mM NaOH in anhydrous MeCN. 85 Figure S3.9. Normalized-current CVs (i.e., current divided by the square root of scan rate) of 0.4 mM Co complexes 2 (a) 5 M H2O (9%, v/v); (b) 5 M H2O (9%, v/v) and 10 mM NaOH; (c) 10 M H2O (18%, v/v) at various scan rates. Inset: plots of ic/ip at 1.50 V vs ν−1/2. 86 Figure S3.10. Normalized-current CVs (i.e., current divided by the square root of scan rate) of 0.4 mM Co complexes 3 (a) 5 M H2O (9%, v/v); (b) 5 M H2O (9%, v/v) and 10 mM NaOH; (c) 5 M H2O (9%, v/v) and 10 mM NaOH* (d) 10 M H2O (18%, v/v) at various scan rates. Inset: plots of ic/ip at 1.50 V vs ν−1/2. *with 15-crown-5. 87 Figure S3.11. CVs of 0.4 mM Co complexes 2 (a) and 3 (c) in anhydrous MeCN at different scan rates (from 10 to 200 mV s−1) in the selected regions for the [cat]3+/[cat]4+ couple waves. (b) 2 and (d) 3 are plots of the anodic and cathodic current maximum of the [cat]3+/[cat]4+ couple as a function of the square root of scan rate (ν1/2). 88 Figure S3.12. A series of 250 consecutive CVs were performed using a concentration of 0.4 mM of 2. The experiments were conducted under the following conditions: (a) in the presence of 5 M H2O (9% v/v), (b) in the presence of 10 M H2O (18% v/v), and (c) with 10 mM NaOH in the presence of 5 M H2O (9% v/v) in MeCN. Scan rate: 100 mV s−1. Supporting electrolyte: 0.1 M [NBu4][PF6]. 91 Figure S3.13. A series of 250 consecutive CVs were performed using a concentration of 0.4 mM of 3. The experiments were conducted under the following conditions: (a) in the presence of 5 M H2O (9% v/v), (b) in the presence of 10 M H2O (18% v/v), and (c) with 10 mM NaOH in the presence of 5 M H2O (9% v/v), (d) 10 mM NaOH with crown ether in the presence of 5 M H2O (9% v/v) in MeCN. Scan rate: 100 mV s−1. Supporting electrolyte: 0.1 M [NBu4][PF6]. 92 Figure S3.14. After completing the CV scan cycles (represented by the red traces), the GC electrode was carefully removed from the solution and thoroughly rinsed with pure MeCN. Subsequently, the rinsed GC electrode (unpolished; depicted by the black trace) was subjected to cycling in a fresh solution of 0.1 M [NBu4][PF6]/MeCN without catalyst (scan rate of 100 mV s−1). The grey trace corresponds to a blank experiment conducted in MeCN without catalyst. The following conditions were employed for the different experiments: (a) 0.4 mM of 2 in the presence of 5 M H2O (9% v/v); (b) 0.4 mM of 2 in the presence of 10 M H2O (18% v/v) and (c) 0.4 mM of 2 in the presence of 10 mM NaOH in 5 M H2O (9% v/v) 93 Figure S3.15. After completing the CV scan cycles (represented by the red traces), the GC electrode was carefully removed from the solution and thoroughly rinsed with pure MeCN. Subsequently, the rinsed GC electrode (unpolished; depicted by the black trace) was subjected to cycling in a fresh solution of 0.1 M [NBu4][PF6]/MeCN without catalyst (scan rate of 100 mV s−1). The grey trace corresponds to a blank experiment conducted in MeCN without catalyst. The following conditions were employed for the different experiments: (a) 0.4 mM of 3 in the presence of 5 M H2O (9% v/v); (b) 0.4 mM of 3 in the presence of 10 M H2O (18% v/v); and (c) 0.4 mM of 3 in the presence of 10 mM NaOH in 5 M H2O (9% v/v); (d) 0.4 mM of 3 in the presence of 10 mM NaOH with crown ether in 5 M H2O (9% v/v) 94 Figure S3.16. SEM images of a GC electrode (a) before and (b–e) after continuous 250 CV scans. Conditions: 0.4 mM 2 (b), 3 (d) with 5 M H2O (9% v/v); 0.4 mM 2 (c), 3 (e) in the presence of 10 mM NaOH with 5M H2O (9% v/v). Supporting electrolyte: 0.1 M [NBu4][PF6] in MeCN. 95 Figure S3.17. EDX spectra of a GC electrode (a) before and (b–e) after continuous 250 CV scans. Conditions: 0.4 mM 2 (b), 3 (d) with 5 M H2O (9% v/v); 0.4 mM 2 (c), 3 (e) in the presence of 10 mM NaOH with 5 M H2O (9% v/v). Supporting electrolyte: 0.1 M [NBu4][PF6] in MeCN. 96 Figure S3.18. EDX mapping image of a GC electrode (a) before and (b–e) after continuous 250 CV scans. Conditions: 0.4 mM 2 (b), 3 (d) with 5 M H2O (9% v/v); 0.4 mM 2 (c), 3 (e) in the presence of 10 mM NaOH with 5 M H2O (9% v/v). Supporting electrolyte: 0.1 M [NBu4][PF6] in MeCN. 97 Figure S3.19. (a) Basic cell configuration for controlled potential electrolysis. (b) Photograph depicting the experimental setup employed for controlled potential electrolysis. 99 Figure S3. 20. (a) Catalytic current curves obtained in CPE experiments with complex 2 and 3, both at a concentration of 0.4 mM, in the presence of 5 M H2O (9%, v/v) in MeCN at a potential of 1.5 V vs Fc+/0 over a duration of 12 hours. (b) Catalytic current curves obtained in CPE experiments with complex 2 and 3, both at a concentration of 0.4 mM, in the presence of 5 M H2O (9%, v/v) and 10 mM NaOH in MeCN at a potential of 1.5 V vs Fc+/0 over a duration of 12 hours. Supporting electrolyte: 0.1 M [NBu4][PF6]. 100 Figure S3. 21. (a) Custom-designed cell utilized for oxygen evolution experiment. (b) and (c) Setup images demonstrating experimental configuration for oxygen evolution analysis. 102 Figure S3.22. (a) Cumulative charge during CPE of a 0.4 mM Co complex 2 & 3 with 5 M H2O (9%, v/v), and 0/10 mM NaOH in 0.1 M [NBu4][PF6]/MeCN at 1.5 V vs Fc+/0 for 1 h. (b) The generation of O2 during the electrolysis process was monitored using an oxygen dipping probe, providing real-time measurements. (c) The evolution of O2 during the electrolysis was calibrated against a literature value. A dashed trace represents the control experiment conducted without the complex, in the presence of 0/10 mM NaOH and 5 M H2O (9%, v/v). The asterisk (*) indicates the presence of 10 mM NaOH. 103 Figure S3.23. Faradaic efficiency of oxygen evolution (right y-axis) and mole comparison between experiments and theoretical value (left y-axis) were evaluated for complex 2 (a) & 3 (b) under neutral, and 2 (c) & 3 (d) under alkaline conditions. All measurements were performed at an applied potential of 1.5 V vs Fc+/0 for a duration of 1 h. 104 Figure S3.24. (a) UV-Visible spectra were recorded to detect varying concentrations of H2O2 (0−18 mM) using TiIV(O)SO4. (b) A calibration curve was established by plotting the absorbance values against the concentrations of H2O2, using the data obtained from Figure S3.15. 106 Figure S3.25. UV-Visible spectra were obtained for H2O2 detection during the catalytic oxidation of H2O using Co complexes. TiIV(O)SO4 treatment resulted in a red trace, while the black trace represented the background spectra without TiIV(O)SO4. Experimental conditions included: 0.4 mM complex 2 (a) & 3 (c) with 5 M H2O (9%, v/v); 0.4 mM complex 2 (b) & 3 (d) with 5 M H2O (9%, v/v) and 10 mM NaOH. 107 Figure S3. 26. CVs of various concentration of Co complexes (0.1–1 mM) in the presence of H2O (5 M; 9%, v/v) and [NBu4][PF6] (0.1 M) in 5 mL MeCN at the scan rate of 100 mV s−1. (a) 2; (c) 2 with 10 mM NaOH; (e) 3; (g) 3 with 10 mM NaOH. Plots of anodic catalytic current derived from the CV data (i, at 1.50 V vs Fc+/0) vs [Co] shows a first-order dependence. (b) 2; (d) 2 with 10 mM NaOH; (f) 3; (h) 3 with 10 mM NaOH. 107 Figure S3.27. CVs of Co complexes (0.4 mM) in the presence of H2O (1–20 M) and [NBu4][PF6] (0.1 M) in 5 mL MeCN at the scan rate of 100 mV s−1. (a) 2; (c) 3. Plots of anodic catalytic current derived from the CV data (i, at 1.50 V vs Fc+/0) vs [H2O]1/2 shows a first-order dependence. (b) 2, (d) 3. 110 Figure S3.28. CVs of 0.4 mM Co complexes 3 (a) in the presence of 5 M H2O (9%, v/v) and (b) in the presence of 10 M H2O (18%, v/v) in MeCN (red solid trace) or 5 M/10M D2O in CD3CN (black solid trace) at the scan rate of 100 mV s−1. Dashed trace: blank with no complex in the presence of 5 M/10 M H2O (red dashed trace) or D2O (black dashed trace) (c) in the presence of 5 M H2O with 10 mM NaOH in MeCN (red solid trace) or 5 M D2O and 10 mM NaOD in CD3CN (black solid trace) at the scan rate of 100 mV s−1. Dashed trace: blank with no complex in the presence of 5 M H2O with 10 mM NaOH (red dashed trace) or 5 M D2O and 10 mM NaOD (black dashed trace). 112 Figure S3.29. CVs of 0.4 mM Co complex 2 in the presence of various concentrations of H2O (5 and 10 M) and NaOH (0 and 10 mM) in MeCN at various scan rates. Inset: plots of ic/ip at 1.50 V vs v −1/2. (a) 5 M H2O (9%, v/v); (c) 5 M H2O (9%, v/v) and 10 mM NaOH; (e) 10 M H2O (18%, v/v). Supporting electrolyte: 0.1 M [NBu4][PF6]. Plots of anodic catalytic current derived from the CVs data (ic, at 1.50 V vs. Fc+/0) vs scan rate (v, V s−1): (b) 5 M H2O (9%, v/v); (d) 5 M H2O (9%, v/v) and 10 mM NaOH; (f) 10 M H2O (18%, v/v). 114 Figure S3.30. CVs of 0.4 mM Co complex 3 in the presence of various concentrations of H2O (5 and 10 M) and NaOH (0 and 10 mM) in MeCN at various scan rates. Inset: plots of ic/ip at 1.50 V vs v −1/2. (a) 5 M H2O (9%, v/v); (c) 5 M H2O (9%, v/v) and 10 mM NaOH; (e) 5 M H2O (9%, v/v) and 10 mM NaOH* (g) 10 M H2O (18%, v/v). Supporting electrolyte: 0.1 M [NBu4][PF6]. Plots of anodic catalytic current derived from the CVs data (ic, at 1.50 V vs. Fc+/0) vs scan rate (v, V s−1): (b) 5 M H2O (9%, v/v); (d) 5 M H2O (9%, v/v) and 10 mM NaOH; (f) 5 M H2O (9%, v/v) and 10 mM NaOH* (h) 10 M H2O (18%, v/v); *with 15-crown-5 115 Figure S3.31. Schematic of the four-electrode cell configuration used for open circuit potential (OCP) measurements. The reduction potential of H+/H2 was measured for a MeCN solution containing [NBu4][PF6] (0.1 M), H2O (5 and 10 M), and NaOH (0 and 10 mM) under 1 atm H2. (Figure S3.31 is reproduced with permission from ref. 18; copyright 2013 American Chemical Society.) 117 Figure S3.32. The black traces show the average OCP of EH+/H2 under catalytic conditions in MeCN solutions under 1atm H2. (a) 5 M H2O (9%, v/v); (b) 5 M H2O (9%, v/v) and 10 mM NaOH; (c) 10 M H2O (18%, v/v). Supporting electrolyte: 0.1 M [NBu4][PF6]. 118 Figure S3.33. (a) Quartz glass spectroelectrochemical cell with a 1mm thin layer. (b) Experimental setup image of apectroelectrochemical experiment. 120 Figure S3.34. UV–Vis spectra exhibited change during the SEC electrolysis of 3 (0.04 mM) at various potentials in presence of 1 mM NBu4OH (a) at 0.40 V, (b) at 0.60 V, (c) at 1.50 V under non-catalytic conditions for 1 h (d) at 1.50 V under catalytic conditions for 1 h. 121 Figure S3.35. UV–Vis spectra exhibited change during the SEC electrolysis of 3 (0.04 mM) at various potentials in presence of 0 or 10 mM NaOH. (a) 3 at 0.40 V; (b) 3 at 0.40 V and 10 mM NaOH; (c) 3 at 0.60 V; (d) 3 at 0.60 V and 10 mM NaOH; (e) 3 at 1.50 V; (f) 3 at 1.50 V and 10 mM NaOH; (g) 3 and 5 M H2O at 1.54 V; (h) 3 with 5 M H2O and 10 mM NaOH. 122 Figure S3.36. NMR spectrum comparing the deprotonation state before (black) and after with different equivalent of NaH for complex 1. 123 Figure S3.37. Solvent suppression NMR spectrum during the catalytic process continuous measurement for 0–70 min (5 min between each data) for 3. Condition: [3]: 5 mM, [NaOH]: 20 mM, [NBu4IO4]: 25 eq, [H2O]: 5 M 124 Figure S3.38. Solvent suppression NMR spectrum during the catalytic process continuous measurement for 0, 5, 25, 50 and 70 min for 3. Condition: [3]: 5 mM, [NaOH]: 20 mM, [NBu4IO4]: 25 eq, [H2O]: 5 M 124 Figure S3.39. X-band EPR spectra of 1 (4 mM) with (a) 0.4 eq oxidant, (b) 1.1 eq oxidant and 3 (4 mM) with (c) 0.4 eq oxidant, (d) 1.1 eq oxidant in neutral condition. Experimental parameters: microwave frequency = 9.63 GHz, microwave power = 10.02 mW. 126 Figure S3.40. X-band EPR spectra of 3 (4 mM) in presence of 5 M H2O with 10 eq (a), 25 eq (c) and 50 eq (e) oxidant in neutral catalytic condition. 3 (4 mM) in presence of 5 M H2O with 10 eq (b), 25 eq (d) and 50 eq (f) oxidant in alkaline catalytic condition. Experimental parameters: microwave frequency = 9.63 GHz, microwave power = 10.02 mW. 127 Figure S3.41. 1H NMR spectrum of A1. 128 Figure S3.42. 13C NMR spectrum of A1. 128 Figure S3.43. 1H NMR spectrum of A2. 129 Figure S3.44. 13C NMR spectrum of A2. 129 Figure S3. 45. ESI-MS of A2. 130 Figure S3.46. 1H NMR spectrum of A3. 130 Figure S3.47. 13C NMR spectrum of A3. 131 Figure S3.48. ESI-MS of A3. 131 Figure S3.49. 1H NMR spectrum of B1. 132 Figure S3.50. 13C NMR spectrum of B1. 132 Figure S3.51. 1H NMR spectrum of B2. 133 Figure S3.52. 13C NMR spectrum of B2. 133 Figure S3.53. 1H NMR spectrum of B2. 134 Figure S3.54. 13C NMR spectrum of B2. 134 Figure S3.55. 1H NMR spectrum of H2L1. 135 Figure S3.56. 13C NMR spectrum of H2L1. 135 Figure S3.57. 1H -13C HSQC NMR spectrum of H2L1. 136 Figure S3.58. 1H -13C HMBC NMR spectrum of H2L1. 137 Figure S3.59. ESI-MS of H2L1. 137 Figure S3.60. 1H NMR spectrum of H2L2. 138 Figure S3.61. 13C NMR spectrum of H2L2. 138 Figure S3. 62. 1H -13C HSQC NMR spectrum of H2L2. 139 Figure S3.63. 1H -13C HMBC NMR spectrum of H2L2. 140 Figure S3.64. EI-MS of H2L2. 140 Figure S3.65. 1H NMR spectrum of H2L3. 141 Figure S3.66. 13C NMR spectrum of H2L3. 141 Figure S3.67. 1H -13C HSQC NMR spectrum of H2L3. 142 Figure S3.68. 1H -13C HMBC NMR spectrum of H2L3. 143 Figure S3.69. ESI-MS of H2L2. 143 Figure S3.70. 1H NMR spectrum of H2L4. 144 Figure S3.71. 13C NMR spectrum of H2L4. 144 Figure S3.72. 1H -13C HSQC NMR spectrum of H2L4. 145 Figure S3.73. 1H -13C HMBC NMR spectrum of H2L3. 146 Figure S3.74. ESI-MS of H2L4. 146 Figure S3.75. 1H NMR spectrum of 1. 147 Figure S3.76. DOSY NMR spectrum of 1. 147 Figure S3.77. DOSY NMR spectrum of 1’. 148 Figure S3.78. 1H NMR spectrum of 2. 149 Figure S3.79. 13C NMR spectrum of 2. 149 Figure S3.80. 1H NMR spectrum of 2. 150 Figure S3.81. 13C NMR spectrum of 2. 150 Figure S3.82. 1H-1H COSY NMR spectrum of 2. 151 Figure S3.83.1H-13C HSQC NMR spectrum of 2. 152 Figure S3.84. 1H-13C HMBC NMR spectrum of 2. 153 Figure S3.85. DOSY NMR spectrum of 2. 154 Figure S3.86. 1H NMR spectrum of 3. 155 Figure S3.87. 13C NMR spectrum of 3. 155 Figure S3.88. DEPT135 and 90 NMR spectrum of 3. 156 Figure S3.89. 1H-1H COSY NMR spectrum of 3. 157 Figure S3.90.1H-13C HSQC NMR spectrum of 3. 158 Figure S3.91. 1H-13C HMBC NMR spectrum of 3. 159 Figure S3.92. DOSY NMR spectrum of 3. 160 Figure S3.93. 1H NMR spectrum of 4. 161 Figure S3.94. 13C NMR spectrum of 4. 161 Figure S3.95. 1H-1H COSY NMR spectrum of 4. 162 Figure S3.96. 1H-13C HSQC NMR spectrum of 4. 163 Figure S3.97. 1H-13C HMBC NMR spectrum of 4. 164 Figure S3. 98. 1H NMR spectrum of [NBu4][OH]. 165 Figure S3.99. 13C NMR spectrum of [NBu4][OH]. 165 Figure S3.100. ESI+-MS of [NBu4][OH]. 166 Figure S3. 101. 1H NMR spectrum of [NBu4][IO4]. 166 Figure S3.102. 13C NMR spectrum of [NBu4][IO4]. 167 Figure S3.103. ESI+-MS of [NBu4][IO4]. 167 Figure S3.104. ESI–-MS of [NBu4][IO4]. 168 Figure S3.105. ORTEP drawings of 2 with thermal ellipsoids at 50% probability. Hydrogen atoms and counter ions are omitted for clarity. 170 Figure S3.106. ORTEP drawings of 3 with thermal ellipsoids at 30% probability. Hydrogen atoms and counter ions are omitted for clarity. 181 Figure S3.107. ORTEP drawings of 4 with thermal ellipsoids at 30% probability. Hydrogen atoms and counter ions are omitted for clarity. 194 Figure S3.108. ORTEP drawings of 1+ with thermal ellipsoids at 50% probability. 209 Figure S3.109. ORTEP drawings of 3+ with thermal ellipsoids at 50% probability. 219 Figure A1.1. 1H NMR spectrum of P1. ………………………………………………………..243 Figure A1.2. 13C NMR spectrum of P1. 243 Figure A1.3. 1H NMR spectrum of P2. 244 Figure A1.4. 13C NMR spectrum of P3. 244 Figure A1.5. 1H NMR spectrum of P5. 245 Figure A1.6. ESI–-MS spectrum of P5. 244 Figure A1.7. 13C NMR spectrum of P7. 245 Figure A1.8. ESI+-MS spectrum of P7. 247 Figure A1.9. 1H NMR spectrum of P8. 248 Figure A1.10. 13C NMR spectrum of P8. 248 Figure A1.11. ESI+-MS spectrum of P8. 249 Figure A1.12. 1H NMR spectrum of P9. 249 Figure A1.13. 13C NMR spectrum of P9. 250 Figure A1.14. ESI+-MS spectrum of P9. 250 Figure A1.15. 1H NMR spectrum of P9’. 251 Figure A1.16. ESI–-MS spectrum of P9’. 251 Figure A1.17. 1H NMR spectrum of P10. 252 Figure A1.18. 13C NMR spectrum of P10. 252 Figure A1.19. ESI–-MS spectrum of P10. 253 Figure A1.20. 1H NMR spectrum of P11. 253 Figure A1.21. 13C NMR spectrum of P11. 254 Figure A1.22. ESI+-MS spectrum of P11. 254 Figure A1.23. 1H NMR spectrum of P12. 255 Figure A1.24. 13C NMR spectrum of P12. 255 Figure A1.25. 1H NMR spectrum of L1. 256 Figure A1.26. 13C NMR spectrum of L1. 256 Figure A1.27. ESI+-MS spectrum of L1. 257 Figure A1.28. 1H NMR spectrum of L2. 257 Figure A1.29. ESI+-MS spectrum of L2. 258 Figure A1.30. 1H NMR spectrum of L3. 258 Figure A1.31. ESI–-MS spectrum of L3. 259 Figure A1.32. 1H NMR spectrum of L4. 259 Figure A1.33. ESI–-MS spectrum of L4. 260 Figure A1.34. 1H NMR spectrum of L5. 260 Figure A1.35. ESI–-MS spectrum of L5. 261 Figure A1.36. 1H NMR spectrum of L6. 261 Figure A1.37. ESI–-MS spectrum of L6. 262 Figure A1. 38. 1H NMR spectrum of C1. 262 Figure A1.39. 13C NMR spectrum of C1. 262 Figure A1.40. 1H NMR spectrum of P2. 263 Figure A1. 41. 1H NMR spectrum of [NBu4]2[Ce(NO3)6]. 264 Figure A1.42. ESI+-MS spectrum of [NBu4]2[Ce(NO3)6]. 264 Figure A1.43. 1H NMR spectrum of [NBu4][HSO5]. 265 Figure A1.44. 13C NMR spectrum of [NBu4][HSO5]. 265 Figure A1.45. 1H NMR spectrum of [NBu4]2[S2O8]. 266 Figure A1.46. 13C NMR spectrum of [NBu4]2[S2O8]. 266 Figure A1. 47. ORTEP drawings of C1 with thermal ellipsoids at 50% probability. Hydrogen atoms and counter ions are omitted for clarity. 268 Figure A1.48. ORTEP drawings of C2 with thermal ellipsoids at 30% probability. Hydrogen atoms and counter ions are omitted for clarity. 276   List of Schemes Scheme 2.1. Synthesis of dinuclear cobalt complexes 1, 2, 3 and 4. 32 Scheme A1.1. Synthesis of P1–P4 ............................................................................................. 235 Scheme A1.2. Synthesis of P5–P7 236 Scheme A1.3. Synthesis of P8–P12 237   List of Tables Table 2.1. A summary of half-wave potentials of Co complexes (1–4) in neutral and alkaline condition in anhydrous MeCN. 39 Table 2.2. Comparison of kinetic parameters for alkaline water oxidation catalyzed by complex 1 and 3. 48 Table 2.3. log(TOFmax)–η data for complex 2 and 3, and previously reported dinuclear cobalt 1 and 1’ WOCs. 61 Table S3.1. A summary of half-wave potentials of Co complexes (2–4) in neutral and alkaline condition in anhydrous MeCN…………………………………………………………………... 85 Table S3.2. A summary of diffusion coefficient of Co complexes (1–3 and 1’) based on the Diffusion-Ordered NMR Spectroscopy (DOSY) in CD3CN. 89 Table S3.3. EDX analysis of a GC electrode before continuous 250 CV scans. 97 Table S3.4. EDX analysis of a GC electrode after continuous 250 CV scans using 0.4 mM of complex 2 under neutral and alkaline conditions. 98 Table S3.5. EDX analysis of a GC electrode after continuous 250 CV scans using 0.4 mM of complex 3 under neutral and alkaline conditions. 98 Table S3.6. A summary of selectivity of H2O oxidation catalyzed by Co complexes under different conditions. 107 Table S3.7. Summary of KIE values for f Co complexes at 1.50 V vs Fc+/0[a]. 112 Table S3.8. A summary of turnover frequencies (TOFs) of Co complexes 2 and 3 under catalytic conditions. 116 Table S3.9. A summary of turnover frequencies (TOFs) of Co complexes 1 and 1’ under catalytic conditions. 116 Table S3.10. A summary of EH+/H2 and EO2/H2O under catalytic conditions. 119 Table S3.11. A summary of overpotentials of H2O oxidation by Co complexes. 119 Table S3.12. Crystal data and structure refinement for 2. 170 Table S3. 13. Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for 2. 171 Table S3.14. Anisotropic Displacement Parameters (Å2×103) for 2. 172 Table S3. 15. Bond Lengths (Å) for 2. 174 Table S3.16. Bond Angles (˚) for 2. 175 Table S3.17. Torsion Angles (˚) for 2. 176 Table S3.18. Hydrogen Atom Coordinates (Å×104) and Isotropic Displacement Parameters (Å2×103) for 2. 178 Table S3.19. Crystal data and structure refinement for 3. 181 Table S3.20. Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for 3. 182 Table S3.21. Anisotropic Displacement Parameters (Å2×103) for 3. 183 Table S3. 22. Bond Lengths (Å) for 3. 185 Table S3.23. Bond Angles (˚) for 3. 186 Table S3.24. Torsion Angles (˚) for 3. 189 Table S3.25. Hydrogen Atom Coordinates (Å×104) and Isotropic Displacement Parameters (Å2×103) for 3. 191 Table S3. 26. Crystal data and structure refinement for 4. 194 Table S3.27. Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for 4. 195 Table S3.28. Anisotropic Displacement Parameters (Å2×103) for 4. 197 Table S3.29. Bond Lengths for 4. 199 Table S3.30. Bond Angles for 4. 200 Table S3.31. Torsion Angles for 4. 203 Table S3.32. Hydrogen Atom Coordinates (Å×104) and Isotropic Displacement Parameters (Å2×103) for 4. 205 Table S3.33. Atomic Occupancy for 4. 207 Table S3.34. Solvent masks information for 4. 207 Table S3.35. Crystal data and structure refinement for 1+. 209 Table S3.36. Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for 1+. 210 Table S3.37. Anisotropic Displacement Parameters (Å2×103) for 1+. 211 Table S3.38. Bond Lengths for 1+. 212 Table S3.39. Bond Angles for 1+. 213 Table S3. 40. Torsion Angles for 1+. 214 Table S3.41. Hydrogen Atom Coordinates (Å×104) and Isotropic Displacement Parameters (Å2×103) for 1+. 216 Table S3.42. Solvent masks information for 1+. 217 Table S3.43. Crystal data and structure refinement for 3+. 219 Table S3.44. Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for 3+. 220 Table S3.45. Anisotropic Displacement Parameters (Å2×103) for 3+. 221 Table S3.46. Bond Lengths for 3+. 223 Table S3.47. Bond Angles for 3+. 224 Table S3.48. Torsion Angles for 3+. 226 Table S3.49. Hydrogen Atom Coordinates (Å×104) and Isotropic Displacement Parameters (Å2×103) for 3+. 228 Table S3.50. Atomic Occupancy for 3+. 229 Table A1.1. Crystal data and structure refinement for C1..............................................................268 Table A1.2. Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for C1. 269 Table A1.3. Anisotropic Displacement Parameters (Å2×103) for C1. 270 Table A1.4. Bond Lengths for C1. 271 Table A1.5. Bond Angles for C1. 272 Table A1.6. Hydrogen Atom Coordinates (Å×104) and Isotropic Displacement Parameters (Å2×103) for C1. 274 Table A1.7. Solvent masks information for C1. 274 Table A1.8. Crystal data and structure refinement for C2. 276 Table A1.9. Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for C2. 277 Table A1.10. Anisotropic Displacement Parameters (Å2×103) for C2. 280 Table A1.11. Bond Lengths for C2. 283 Table A1.12. Bond Angles for C2. 284 Table A1.13. Torsion Angles for C2. 288 Table A1.14. Hydrogen Atom Coordinates (Å×104) and Isotropic Displacement Parameters (Å2×103) for C2. 291 Table A1.15. Atomic Occupancy for C2. 292 Table A1.16. Solvent masks information for C2. 293

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