在生物學與醫藥學方面，金屬與含硫的生物配位基像半胱胺酸和榖胱甘肽之間的作用力是一門很重要的課題。所以我們致力於了解釩與鐵金屬和官能基類似於半胱胺酸和榖胱甘肽的含硫配位基之間的基礎化學。因此在這份研究裡，我們主要研究方向在於釩硫和鐵硫的化學。
在第一部份中，我們成功的合成出一系列釩硫化合物分別為：[VIV2(μ-OMe)3(PS3”)]- (1), [VVO(PS3”)(OMe)]- (2), [VV(PS3”)2]- ↔ [VIV(PS3”)(PS3”˙)]- (3)和[VIV(PS3‟)2]2- (4)，同時也鑑定了這些錯合物的固態結構。錯合物1是一個雙核非含氧釩化合物，每一個釩金屬皆有七個原子配位。錯合物2是一個具有六配位的五價含氧釩金屬中心。錯合物1和2在文獻上都是少有的四價雙核非含氧釩硫化合物與五價含氧釩硫化合物。在這部份的研究中，錯合物3是一個值得注意的化合物，依據一些光譜的鑑定，它可以被視為是以一個具有自由基的四價釩硫錯合物與五價釩硫錯合物的共振形式存在。由此結果暗示著具有自由基的四價釩硫化合物可以穩定的存在於生物系統中。而錯合物3和4它們中心金屬的配位數皆類似於天然存在的amavadin。
此研究的第二部份，我們合成並鑑定了錯合物[Fe(PS3”)(CH3CN)]- (5)和[Fe(PS3”)(N2H4)]- (6)的固態結構。藉由X-射線晶體學可知道錯合物5和6中心鐵金屬都是五配位的雙三角錐幾何結構。而錯合物5可以當作是固氮酵素的模擬化合物，它能在額外加入電子與質子環境下進行催化聯胺還原成氨氣的反應。錯合物6是一個具有聯胺鍵分子結的化合物，其為固氮酵素催化氮氣還原成氨氣之過程中可能的基質及中間體，所以由此研究提供一個可能性的假設，在固氮酵素的活化中心鉬鐵輔助因子裡，單鐵的位置可進行最後一步的固氮步驟。

The interaction of transition metal ions with sulfur containing bioligands such as cysteine and glutathione is an essential subject in various biological and medical aspects. Thus, efforts have been made on understanding fundamental chemistry of vanadium and iron complexes with thiolato ligands that mimic S-donars in cysteine and glutathione. Against this motivation, we focus on vanadium and iron thiolate chemistry at this work.
At the first part of this work, we have synthesized and characterized a series of vanadium thiolate complexes, [VIV2(μ-OMe)3(PS3”)]- (1), [VVO(PS3”)(OMe)]- (2), [VV(PS3”)2]- ↔ [VIV(PS3”)(PS3”˙)]- (3), [VIV(PS3‟)2]2- (4). Complex 1 is a dinuclear non-oxovanadium(IV) compound. Complex 2 has a six-coordinated oxovanadium(V) center. These two complexes are rare examples for non-oxodivanadium(IV) and oxovanadium(V) thiolate complexes, respectively. Notably, compelx 3 has a formal oxidation of +5, however, the electronic structure of complex 3 is better to be understood as the resonance forms of V(V)-thiolate and V(IV)-thiyl radical species. In addition, complexes 3 and 4 have an unusual coordination number of eight similar to that in amavadin, a natural product found in Amanita mushrooms.
In the second part, we report the syntheses and characterization of iron(II) thiolate complexes, [Fe(PS3”)(CH3CN)]- (5) and [Fe(PS3”)(N2H4)]- (6). The structures of 5 and 6 resolved from X-ray crystallography consist of five-coordinate iron(II) centers with trigonal-bipyramidal geometry. Importantly, complex 5 can catalyze the reduction of hydrazine to ammonia with external proton and electron sources. Hydrazine is an alternative substrate, as well as a proposed intermediate of nitrogenase. Furthermore, the substrate bound adduct, [Fe(PS3”)(N2H4)]- (6) was also isolated and characterized. Therefore, this work provides a likelihood that a single iron site in MoFe-cofactor of the enzyme can carry the late stage of nitrogen fixation.

Part I : Chemistry of Vanadium Thiolate Complexes: the Isolation of a Vanadium Thiolate Complex with Charge Delocalization between V(V)-thiolate and V(IV)-thiyl Radical Forms
1. Huyer, G.; Liu, S.; Kelly, J.; Moffat, J.; Payette, P.; Kennedy, B.; Tsaprailis, G.; Gresser, M. J.; Ramachandran, C., Mechanism of inhibition of protein-tyrosine phosphatases by Vanadate and Pervanadate. J. Biol. Chem. 1997, 272 (2), 843-851.
2. (a) Benabe, J. E.; Echegoyen, L. A.; Pastrana, B.; Martinez-Maldonado, M., Mechanism of inhibition of glycolysis by vanadate. J. Biol. Chem. 1987, 262 (20), 9555-9560; (b) Rehder, D., Biological and medicinal aspects of vanadium. Inorg. Chem. Commun. 2003, 6, 604-617.
3. (a) Taylor, S. W.; Kammerer, B.; Bayer, E., New Perspectives in the Chemistry and Biochemistry of the Tunichromes and Related Compounds. Chem. Rev. 1997, 97, 333-346; (b) Michibata, H.; Yamaguchi, N.; Uyama, T.; Ueki, T., Molecular biological approaches to the accumulation and reduction of vanadium by ascidians. Coord. Chem. Rev. 2003, 237, 41-51.
4. (a) Garner, C. D.; Armstrong, E. M.; Berry, R. E.; Beddoes, R. L.; Collison, D.; Cooney, J. J. A.; Ertok, S. N.; Helliwell, M., Investigations of Amavadin. J. Inorg. Biochem. 2000, 80 (1-2), 17-20; (b) Berry, R. E.; Armstrong, E. M.; Beddoes, R. L.; Collison, D.; Ertok, S. N.; Helliwell, M.; Garner, C. D., The structure characterization of Amavadin. Angew. Chem. Int. Ed. 1999, 38, 795-797.
5. Bruech, M.; Quintanilla, M. E.; Legrum, W.; Koch, J.; Netter, K. J.; Fuhrmann, G. F., Effects of vanadate on intracellular reduction equivalents in mouse liver and the fate of vanadium in plasma, erythrocytes and liver. Toxicology 1984, 31 (3-4), 283-295.
6. Giles, N. M.; Giles, G. I.; Jacob, C., Multiple roles of cysteine in biocatalysis. Biochem. Biophys. Res. Commun. 2003, 300 (1), 1-4.
7. (a) Licht, S.; Gerfen, G. J.; Stubbe, J., Thiyl Radicals in Ribonucleotide Reductases Science 1996, 271 (5248), 477-481; (b) Stubbe, J.; Nocera, D. G.; Yee, C. S.; Chang, M. C. Y., Radical Initiation in the Class I Ribonucleotide Reductase: Long-Range Proton-Coupled Electron Transfer? Chem. Rev. 2003, 103 (6), 2167-2202.
8. Fontecave, M.; Ollagnier-de-Choudens, S.; Mulliez, E., Biological Radical Sulfur Insertion Reactions. Chem. Rev. 2003, 103 (6), 2149-2166.
9. Marr, A. C.; Spencer, D. J. E.; Schröder, M., Structural mimics for the active site of [NiFe] hydrogenase. Coord. Chem. Rev. 2001, 219-221, 1055-1074.
10. (a) Sono, M.; Roach, M. P.; Coulter, E. D.; Dawson, J. H., Heme-Containing Oxygenases. Chem. Rev. 1996, 96 (7), 2841-2888; (b) Stubbe, J.; Donk, W. A. v. d., Protein Radicals in Enzyme Catalysis. Chem. Rev. 1998, 98, 705; (c) Whittaker, J.W., Free Radical Catalysis by Galactose Oxidase. Chem. Rev. 2003, 103, 2347.
11. (a) Groves, J. T.; Haushalter, R. C.; Nakamura, M.; Nemo, T. E.; Evans, B. J., High-valent iron-porphyrin complexes related to peroxidase and cytochrome P-450. J. Am. Chem. Soc. 1981, 103 (10), 2884-2886; (b) Fujii, H., Electronic structure and reactivity of high-valent oxo iron porphyrins. Coord. Chem. Rev. 2002, 226 (1-2), 51-60.
12. (a) Song, W. J.; Seo, M. S.; DeBeer George, S.; Ohta, T.; Song, R.; Kang, M.-J.; Tosha, T.; Kitagawa, T.; Solomon, E. I.; Nam, W., Synthesis, Characterization, and Reactivities of Manganese(V)−Oxo Porphyrin Complexes. J. Am. Chem. Soc. 2007, 129 (5), 1268-1277; (b) Geethalakshmi, K. R.; Waller, M. P.; Buhl, M., The Presumption of Innocence? A DFT-Directed Verdict on Oxidized Amavadin and Vanadium Catecholate Complexes. Inorg. Chem. 2007, 46 (26), 11297-11307; (c) Edwards, N. Y.; Eikey, R. A.; Loring, M. I.; Abu-Omar, M. M., High-Valent Imido Complexes of Manganese and Chromium Corroles. Inorg. Chem. 2005, 44 (10), 3700-3708; (d) Storr, T.; Verma, P.; Pratt, R. C.; Wasinger, E. C.; Shimazaki, Y.; Stack, T. D. P., Defining the Electronic and Geometric Structure of One-Electron Oxidized Copper−Bis-phenoxide Complexes. J. Am. Chem. Soc. 2008, 130 (46), 15448-15459; (e) Grohol, D.; Papoutsakis, D.; Nocera, D. G., Angew. Chem., Int. Ed. 2001, 40, 1519; (f) Ghosh, P.; Begum, A.; Herebian, D.; Bothe, E.; Hildenbrand, K.; Weyhermüller, T.; Wieghardt, K., Coordinated o-Dithio- and o-Iminothiobenzosemiquinonate(1−) π-Radicals in [MII(bpy)(L˙)](PF6) Complexes. Angew. Chem. Int. Ed. 2003, 42 (5), 563-567; (g) Hsieh, C. H.; Hsu, I. J.; Lee, C. M.; Ke, S. C.; Wang, T. Y.; Lee, G. H.; Wang, Y.; Chen, J. M.; Lee, J. F.; Liaw, W. F., Nickel Complexes of o-Amidochalcogenophenolate(2-)/o-Iminochalcogenobenzosemiquinonate(1-) π-Radical: Synthesis, Structures, Electron Spin Resonance, and X-ray Absorption Spectroscopic Evidence. Inorg. Chem. 2003, 42 (12), 3925-3933; (h) Lu, C. C.; DeBeer George, S.; Weyhermüller, T.; Bill, E.; Bothe, E.; Wieghardt, K., An Electron-Transfer Series of High-Valent Chromium Complexes with Redox Non-Innocent, Non-Heme Ligands. Angew. Chem. Int. Ed. 2008, 47 (34), 6384-6387; (i) Cornman, C. R.; Colpas, G. J.; Hoeschele, J. D.; Kampf, J.; Pecoraro, V. L., Implications for the spectroscopic assignment of vanadium biomolecules: structural and spectroscopic characterization of monooxovanadium(V) complexes containing catecholate and hydroximate based noninnocent ligands. J. Am. Chem. Soc. 1992, 114, 9925.
13. (a) Nazari Verani, C.; Gallert, S.; Bill, E.; Weyhermuller, T.; Wieghardt, K.; Chaudhuri, P., [Tris(o-iminosemiquinone)cobalt(III)]-a radical complex with an St =
3/2 ground state. Chem. Commun. 1999, (17), 1747-1748; (b) Chaudhuri, P.; Verani, C. N.; Bill, E.; Bothe, E.; Weyhermüller, T.; Wieghardt, K., Electronic Structure of Bis(o-iminobenzosemiquinonato)metal Complexes (Cu, Ni, Pd). The Art of Establishing Physical Oxidation States in Transition-Metal Complexes Containing Radical Ligands. J. Am. Chem. Soc. 2001, 123 (10), 2213-2223; (c) Chun, H.; Verani, C. N.; Chaudhuri, P.; Bothe, E.; Bill, E.; Weyhermüller, T.; Wieghardt, K., Molecular and Electronic Structure of Octahedral o-Aminophenolato and o-Iminobenzosemiquinonato Complexes of V(V), Cr(III), Fe(III), and Co(III). Experimental Determination of Oxidation Levels of Ligands and Metal Ions. Inorg. Chem. 2001, 40 (17), 4157-4166; (d) Chun, H.; Weyhermüller, T.; Bill, E.; Wieghardt, K., Tuning the Electronic Structure of Halidobis(o-imino-benzosemiquinonato)iron(III) Complexes. Angew. Chem. Int. Ed. 2001, 40 (13), 2489-2492; (e) Sun, X.; Chun, H.; Hildenbrand, K.; Bothe, E.; Weyhermüller, T.; Neese, F.; Wieghardt, K., o-Iminobenzosemiquinonato(1−) and o-Amidophenolato(2−) Complexes of Palladium(II) and Platinum(II): A Combined Experimental and Density Functional Theoretical Study. Inorg. Chem. 2002, 41 (16), 4295-4303; (f) Kokatam, S.; Weyhermüller, T.; Bothe, E.; Chaudhuri, P.; Wieghardt, K., Structural Characterization of Four Members of the Electron-Transfer Series [PdII(L)2)2]n (L = o-Iminophenolate Derivative; n = 2−, 1−, 0, 1+, 2+). Ligand Mixed Valency in the Monocation and Monoanion with S = 1/2 Ground States. Inorg. Chem. 2005, 44 (10), 3709-3717.
14. Kimura, S.; Bill, E.; Bothe, E.; Weyhermuller, T.; Wieghardt, K., Phenylthiyl Radical Complexes of Gallium(III), Iron(III), and Cobalt(III) and Comparison with Their Phenoxyl Analogues. J. Am. Chem. Soc. 2001, 123 (25), 6025-6039.
15. Tripathi, G. N. R.; Sun, Q.; Armstrong, D. A.; Chipman, D. M.; Schuler, R. H., Resonance Raman spectra and structure of phenylthiyl radical. J. Phys. Chem. 1992, 96 (13), 5344-5350.
16. Springs, J.; Janzen, C. P.; Darensbourg, M. Y.; Calabrese, J. C.; Krusic, P. J.; Verpeaux, J. N.; Amatore, C., Electron paramagnetic resonance and electrochemical study of the oxidation chemistry of mononuclear and binuclear chromium carbonyl thiolates. J. Am. Chem. Soc. 1990, 112 (15), 5789-5797.
17. Grapperhaus, C. A.; Poturovic, S., Electrochemical Investigations of the [Tris(2-(diphenylphosphino)thiaphenolato)ruthenate(II)] Monoanion Reveal Metal- and Ligand-Centered Events: Radical, Reactivity, and Rate. Inorg. Chem. 2004, 43 (10), 3292-3298.
18. Branscombe, N. D. J.; Atkins, A. J.; Marin-Becerra, A.; McInnes, E. J. L.; Mabbs, F. E.; McMaster, J.; Schroder, M., Ni(III) vs. Ni(II)-thiyl radical:charge-delocalisation in a binuclear Ni(III)Ni(II)-dithiolate complex. Chem. Commun. 2003, (9), 1098-1099.
19. Stenson, P. A.; Board, A.; Marin-Becerra, A.; Blake, A. J.; Davies, E. S.; Wilson, C.; McMaster, J.; Schröder, M., Molecular and Electronic Structures of One-Electron Oxidized NiII–(Dithiosalicylidenediamine) Complexes: NiIII–Thiolate versus NiII–Thiyl Radical States. Chem. Eur. J. 2008, 14 (8), 2564-2576.
20. Bayer, E.; Kneifel, H. Z., Naturforsch 1972, 27B, 207.
21. Kneifel, H.; Bayer, E., Determination of the Structure of the Vanadium Compound, Amavadine, from Fly Agaric. Angew. Chem., Int. Ed. in Engl. 1973, 12 (6), 508-508.
22. (a) Bonamico, M.; Dessy, G.; Fares, V.; Scaramuzza, L., Structural studies of eight-co-ordinate metal complexes. Part I. Crystal and molecular structures of tetrakis(phenyldithioacetato)vanadium(IV) and tetrakis(dithiobenzoato)vanadium(IV). J. Chem. Soc., Dalton Trans. 1974, (12), 1258-1263; (b) Sutradhar, M.; Mukherjee, G.; Drew, M. G. B.; Ghosh, S., Simple General Method of Generating Non-oxo, Non-amavadine Model Octacoordinated Vanadium(IV) Complexes of Some Tetradentate ONNO Chelating Ligands from Various Oxovanadium(IV/V) Compounds and Structural Characterization of One of Them. Inorg. Chem. 2007, 46 (12), 5069-5075; (c) Smith, P. D.; Berry, R. E.; Harben, S. M.; Beddoes, R. L.; Helliwell, M.; Collison, D.; Garner, C. D., New vanadium(IV) and V(V) analogues of Amavadin. J. Chem. Soc., Dalton Trans. 1997, 4509-4516; (d) de C. T. Carrondo, M. A. A. F.; Duarte, M. T. L. S.; Pessoa, J. C.; Silva, J. A. L.; da Silva, J. J. R. F.; Vaz, M. C. T. A.; Vilas-Boas, L. F., Bis-(N-hydroxy-iminodiacetate)vanadate(IV), a synthetic model of 'amavadin'. J. Chem. Soc., Chem. Commun. 1988, (17), 1158-1159; (e) Armstrong, E. M.; Beddoes, R. L.; Calviou, L. J.; Charnock, J. M.; Collison, D.; Ertok, N.; Naismith, J. H.; Garner, C. D., The chemical nature of amavadin. J. Am. Chem. Soc. 1993, 115 (2), 807-808; (f) Hubregtse, T.; Kooijman, H.; Spek, A. L.; Maschmeyer, T.; Sheldon, R. A.; Arends, I. W. C. E.; Hanefeld, U., Study on the isomerism in meso-amavadin and an amavadin analogue. J. Inorg. Biochem. 2007, 101 (6), 900-908.
23. (a) Nanda, K. K.; Sinn, E.; Addison, A. W., The first oxovanadium(V)-thiolate complex, [VO(SCH2CH2)3N]. Inorg. Chem. 1996, 35 (11), 1-2; (b) Cornman, C. R.; Stauffer, T. C.; Boyle, P. D., Oxidation of a Vanadium(V)-Dithiolate Complex to a Vanadium(V)-Disulfenate Complex. J. Am. Chem. Soc. 1997, 119, 5986-5987; (c) Davies, S. C.; Hughes, D. L.; Janas, Z.; Jerzykiewicz, L. B.; Richards, R. L.; Sanders, J. R.; Silverston, J. E.; Sobota, P., Vanadium Complexes of the N(CH2CH2S)33- and O(CH2CH2S)22- Ligands with Coligands Relevant to Nitrogen Fixation Processes. Inorg. Chem. 2000, 39 (16), 3485-3498; (d) Nekola, H.; Wang, D.; Grüning, C.; Gätjens, J.; Behrens, A.; Rehder, D., Thiofunctional Vanadium Complexes. Inorg. Chem. 2002, 41 (9), 2379-2384.
24. (a) Halbert, T. R.; Hutchings, L. L.; Rhodes, R.; Stiefel, E. I., Induced redox reactivity of tetrathiovanadate(V): synthesis of the vanadium(IV) dimer V2(μ-S2)2(i-Bu2NCS2)4 and its structural relationship to the V/S mineral patronite. J. Am. Chem. Soc. 1986, 108 (20), 6437-6438; (b) Duraj, S. A.; Andras, M. T.; Kibala, P. A., Metal-metal bonds involving vanadium atoms. A facile synthesis of a novel divanadium tetrakis(dithioacetate) that contains two .mu.-.eta.2-S2 bridges from bis(benzene)vanadium(0) and dithioacetic acid. Inorg. Chem. 1990, 29 (6), 1232-1234.
25. (a) Frank, P.; Hodgson, K. O., Defining Chemical Species in Complex Environments Using K-Edge X-ray Absorption Spectroscopy: Vanadium in Intact Blood Cells and Henze Solution from the Tunicate Ascidia ceratodes. Inorg. Chem. 2000, 39, 6018; (b) Sproules, S.; Weyhermu ller, T.; DeBeer, S.; Wieghardt, K., Six-Membered Electron Transfer Series [V(dithiolene)3]z (z = 1+, 0, 1−, 2−, 3−, 4−). An X-ray Absorption Spectroscopic and Density Functional Theoretical Study. Inorg. Chem. 2010, 49 (11), 5241-5261; (c) Shulman, G. R.; Yafet, Y.; Eisenberger, P.; Blumberg, W. E., Observations and interpretation of x-ray absorption edges in iron compounds and proteins Proc. Natl. Acad. Sci. U.S.A. 1976, 73, 1384.
26. (a) Hoard, J. L.; Silverton, J. V., Stereochemistry of Discrete Eight Coordination. I. Basic Analysis. Inorg. Chem. 1963, 2 (2), 235; (b) Lippard, S. J.; Russ, B. J., Comment on the Choice of an Eight-Coordinate Polyhedron. Inorg. Chem. 1968, 7 (8), 1686-1688.
27. Ooms, K. J.; Bolte, S. E.; Baruah, B.; Choudhary, M. A.; Crans, D. C.; Polenova, T., 51V solid-state NMR and density functional theory studies of eight-coordinate non-oxo vanadium complexes: oxidized amavadin. Dalton Trans. 2009, (17), 3262-3269.
28. Hsu, H.-F.; Su, C.-L.; Gopal, N. O.; Wu, C.-C.; Chu, W.-C.; Tsai, Y.-F.; Chang, Y.-H.; Liu, Y.-H.; Kuo, T.-S.; Ke, S.-C., Redox Chemistry in the reaction of oxovanadium(V) with thiolate containing ligands: The isolation and characterization of nonoxovanadium(IV) complexes containing the forming disulfide and thioether. Eur. J. Inorg. Chem. 2006, 1161-1167.

Part II.Chemistry of Iron Thiolate Complexes relevant to Nitrogenase
1. Howard, J. B.; Rees, D. C., Structural Basis of Biological Nitrofen Fixation. Chem. Rev. 1996, 96, 2965-2982.
2. Alberty, R. A., Thermodynamics of the Nitrogenase Reactions. J. Biol. Chem. 1994, 269, 7099.
3. Eady, R. R., Structure-Function Relationships of Alternative Nitrogenases. Chem. Rev. 1996, 96, 3013-3030.
4. (a) Einsle, O.; Tezcan, F. A.; Andrade, S. L. A.; Schmid, B.; Yoshida, M.; Howard, J. B.; Rees, D. C., Nitrogenase MoFe-Protein at 1.16 A Resolution: A Central Ligand in the FeMo-Cofactor. Science 2002, 297, 1696-1700; (b) Georgiadis, M. M.; Komiya, H.; Chakrabarti, P.; Woo, D.; Kornuc, J. J.; Rees, D. C., Science 1992, 257, 1653.
5. (a) Hinnemann, B.; Norskov, J. K., Modeling a Central Ligand in the Nitrogenase FeMo Cofactor. J. Am. Chem. Soc. 2003, 125 (6), 1466-1467; (b) Yang, T.-C.; Maeser, N. K.; Laryukhin, M.; Lee, H.-I.; Dean, D. R.; Seefeldt, L. C.; Hoffman, B. M., The Interstitial Atom of the Nitrogenase FeMo-Cofactor: ENDOR and ESEEN Evidence That it is not a Nitrogen. J. Am. Chem. Soc. 2005, 127, 12804-12805.
6. (a) Leigh, G. J., Protonation of coordinated dinitrogen. Acc. Chem. Res. 1992, 25 (4), 177-181; (b) MacKay, B. A.; Fryzuk, M. D., Dinitrogen Coordination Chemistry: On the Biomimetic Borderlands. Chem. Rev. 2004, 104 (2), 385-402.
7. Yandulov, D. V.; Schrock, R. R., Catalytic Reduction of Dinitrogen to Ammonia at a Single Molybdenum Center. Science 2003, 301, 76-78.
8. Chen, Y.; Zhou, Y.; Chen, P.; Tao, Y.; Li, Y.; Qu, J., Nitrogenase Model Complexes [Cp*Fe(μ-SR1)2(μ-η2-R2N=NH)FeCp*] (R1 = Me, Et; R2 = Me, Ph; Cp* = η5-C5Me5): Synthesis, Structure, and Catalytic N-N Bond Cleavage of Hydrazines on Diiron Centers. J. Am. Chem. Soc. 2008, 130 (46), 15250-15251.
9. Verma, A. K.; Lee, S. C., Reductive Cleavage of the N−N Bond: Synthesis of Imidoiron(III) Cubanes. J. Am. Chem. Soc. 1999, 121 (46), 10838-10839.
10. (a) Sellmann, D.; Soglowek, W.; Knoch, F.; Moll, M., Nitrogenase Model Compounds: [μ-N2H2{Fe(“NHS4”)}2], the Prototype for the Coordination of Diazene to Iron Sulfur Centers and Its Stabilization through Strong N-H …S Hydrogen Bonds. Angew. Chem. Int. Ed. Engl. 1989, 28 (9), 1271-1272; (b) Sellmann, D.; Hennige, A., Direct Proof of trans-Diazene in Solution by Trapping and Isolation of the Trapping Products. Angew. Chem. Int. Ed. Engl. 1997, 36 (3), 276-278; (c) Sellmann, D.; Hennige, A.; Heinemann, F. W., Transition metal complexes with sulfur ligands part CXXIX. Retention and reactivity of the [Fe=NH=NH=Fe] chromophore in the iron sulfur diazene complex [μ-N2H2{Fe(PPr3)(`S4')}2] in exchange and oxidation processes. (`S4'2- = 1,2-bis(2-mercaptophenylthio)ethane(2-)). Inorg. Chim. Acta 1998, 280 (1-2), 39-49; (d) Sellmann, D.; Blum, D. C. F.; Heinemann, F. W., Transition metal complexes with sulfur ligands. Part CLV. Structural and spectroscopic characterization of hydrogen bridge diastereomers of [μ-N2H2{Fe(PR3)(`tpS4')}2] diazene complexes (`tpS4'2-=1,2-bis(2-mercaptophenylthio)phenylene(2-)). Inorg. Chim. Acta 2002, 337, 1-10; (e) Sellmann, D.; Soglowek, W.; Knoch, F.; Ritter, G.; Dengler, J., Transition-metal complexes with sulfur ligands. 88. Dependence of spin state, structure, and reactivity of [FeII(L) 'NHS4')] complexes on the coligand L (L = CO, N2H2, N2H4, NH3, pyridine, NHCH3NH2, CH3OH, THF, P(OCH3)3, P(OPh)3): model complexes for iron nitrogenases ('NHS4'2-: dianion of 2,2'-bis[(2-mercaptophenyl)thio]diethylamine). Inorg. Chem. 1992, 31 (18), 3711-3717; (f) Sellmann, D.; Shaban, S.; Heinemann, F., Syntheses, Structures and Reactivity of Electron-Rich Fe and Ru Complexes with the New Pentadentate Ligand Et2NpyS4−H2 {4-(Diethylamino)2,6-bis[(2-mercaptophenyl)thiomethyl]pyridine}. Eur. J. Inorg. Chem. 2004, 2004 (23), 4591-4601; (g) Sellmann, D.; Utz, J.; Blum, N.; Heinemann, F. W., On the function of nitrogenase FeMo cofactors and competitive catalysts: chemical principles, structural blue-prints, and the relevance of iron sulfur complexes for N2 fixation. Coord. Chem. Rev. 1999, 190-192, 607-627.
11. (a) Smith, J. M.; Lachicotte, R. J.; Pittard, K. A.; Cundari, T. R.; Lukat-Rodgers, G.; Rodgers, K. R.; Holland, P. L., Stepwise Reduction of Dinitrogen Bond Order by a Low-Coordinate Iron Complex. J. Am. Chem. Soc. 2001, 123 (37), 9222-9223; (b) Smith, J. M.; Sadique, A. R.; Cundari, T. R.; Rodgers, K. R.; Lukat-Rodgers, G.; Lachicotte, R. J.; Flaschenriem, C. J.; Vela, J.; Holland, P. L., Studies of Low-Coordinate Iron Dinitrogen Complexes. J. Am. Chem. Soc. 2006, 128 (3), 756-769.
12. Smith, J. M.; Lachicotte, R. J.; Holland, P. L., N=N Bond Cleavage by a Low-Coordinate Iron(II) Hydride Complex. J. Am. Chem. Soc. 2003, 125 (51), 15752-15753.
13. Vela, J.; Stoian, S.; Flaschenriem, C. J.; Munck, E.; Holland, P. L., A Sulfido-Bridged Diiron(II) Compound and Its Reactions with Nitrogenase-Relevant Substrates. J. Am. Chem. Soc. 2004, 126 (14), 4522-4523.
14. Betley, T. A.; Peters, J. C., Dinitrogen Chemistry from Trigonally Coordinated Iron and Cobalt Platforms. J. Am. Chem. Soc. 2003, 125 (36), 10782-10783.
15. Betley, T. A.; Peters, J. C., A Tetrahedrally Coordinated L3Fe-Nx Platform that Accommodates Terminal Nitride (FeIV≡N) and Dinitrogen (FeI-N2-FeI) Ligands. J. Am. Chem. Soc. 2004, 126 (20), 6252-6254.
16. (a) Mankad, N.; Whited, M.; Peters, J., Terminal FeI-N2 and FeII⋅⋅⋅H-C Interactions Supported by Tris(phosphino)silyl Ligands. Angew. Chem. Int. Ed. 2007, 46 (30), 5768-5771; (b) Whited, M. T.; Mankad, N. P.; Lee, Y.; Oblad, P. F.; Peters, J. C.,Dinitrogen Complexes Supported by Tris(phosphino)silyl Ligands. Inorg. Chem. 2009, 48 (6), 2507-2517.
17. Lee, Y.; Mankad, N. P.; Peters, J. C., Triggering N2 uptake via redox-induced expulsion of coordinated NH3 and N2 silylation at trigonal bipyramidal iron. Nature Chemistry 2010, 2, 558.
18. Komiya, S.; Akita, M.; Yoza, A.; Kasuga, N.; Fukuoka, A.; Kai, Y., Isolation of a zerovalent iron dinitrogen complex with 1,2-bis(diethylphosphino)ethane ligands. J. Chem. Soc., Chem. Commun. 1993, (9), 787-788.
19. (a) George, T. A.; Rose, D. J.; Chang, Y.; Chen, Q.; Zubieta, J., Reduction of Dinitrogen to Ammonia and Hydrazine in Iron(0) and Molybdenum(0) Complexes Containing the N(CH2CH2PPh2)3 Ligand. Crystal Structures of [FeH(L)(N(CH2CH2PPh2)3)][BPh4] (L = N2, CO). Inorg. Chem. 1995, 34 (5), 1295-1298; (b) Field, L. D.; Guest, R. W.; Turner, P., Mixed-Valence Dinitrogen-Bridged Fe(0)/Fe(II) Complex. Inorg. Chem. 2010, 49 (19), 9086-9093.
20. Crossland, J. L.; Zakharov, L. N.; Tyler, D. R., Synthesis and Characterization of an Iron(II) η2-Hydrazine Complex. Inorg. Chem. 2007, 46 (25), 10476-10478.
21. Field, L. D.; Li, H. L.; Dalgarno, S. J.; Turner, P., The first side-on bound metal complex of diazene, HN=NH. Chem. Commun. 2008, (14), 1680-1682.
22. (a) Schrock, R. R.; Glassman, T. E.; Vale, M. G., Cleavageof the N-N bond in a high-oxidation-state Tungsten or molybdenum Hydrazine Complex and the catalytic reduction of hydrazine. J. Am. Chem. Soc. 1991, 113, 725-726; (b) Schrock, R. R.; Glassman, T. E.; Vale, M. G.; Kol, M., High-Oxidation-State Pentamethylcyclopentadienyl Tungsten Hydrazine and Hydrazido Complexes and cleavage of the N-N bond. J. Am. Chem. Soc. 1993, 115, 1760-1772.
23. (a) Block, E.; Ofori-Okai, G.; Kang, H.; Zubieta, J., Catalytic disproportionation and reduction of hydrazine by sulfur-ligated molybdenum(IV) complexes. Characterization of the catalytic precursor [(2-SC5H3N-3-SiMe3)Cl2Mo(μ-S2)( μ-2-SC5H3NH-3-SiMe3)MoCl2(2-SC5H3N-3-SiMe3)].cntdot.thf. J. Am. Chem. Soc. 1992, 114 (2), 758-759; (b) Hitchcock, P. B.; Hughes, D. L.; Maguire, M. J.; Marjani, K.; Richards, R. L., Disproportionation and Reduction of hydrazine at a molybdenum-thiolate center: crystal structures of. J. Chem. Soc. Dalton Trans. 1997, 4747-4752.
24. (a) Malinak, S. M.; Demadis, K. D.; Coucouvanis, D., Catalytic Reduction of Hydrazine to Ammonia by the VFe3S4 Cubanes. Further Evidence for the Direct Involvement of the Heterometal in the Reduction of Nitrogenase Substrates and Possible Relevance to the Vanadium Nitrogenases. J. Am. Chem. Soc. 1995, 117 (11), 3126-3133; (b) Crans, D. C.; Smee, J. J.; Gaidamauskas, E.; Yang, L., That chemistry and Biochemistry of vanadium and the biological activities exerted by vanadium compounds. Chem. Rev. 2004, 104, 849-902; (c) Coucouvanis, D.; Mosier, P. E.; Demadis, K. D.; Patton, S.; Malinak, S. M.; Kim, C. G.; Tyson, M. A., The catalytic reduction of hydrazine to ammonia by the MoFe3S4 cubanes and implications regarding the function of nitrogenase. Evidence of the molybdenum atom in substrate reduction. J. Am. Chem. Soc. 1993, 115, 12193-12194.
25. Chu, W.-C.; Wu, C.-C.; Hsu, H.-F., Catalytic Reduction of Hydrazine to Ammonia by a Vanadium Thiolate Complex. Inorg. Chem. 2006, 45, 3164-3166.
26. Hsu, H.-F.; Chu, W.-C.; Hung, C.-H.; Liao, J.-H., The First Example of a Seven-coordinate Vanadium(III) Thiolate Complex Containing the Hydrazine Molecule, an Intermediate of Nitrogen Fixation. Inorg. Chem. 2003, 42, 7369-7371.
27. Reger, D. L.; Wright, T. D.; Little, C. A.; Lamba, J. J. S.; Smith, M. D., Control of the stereochemical impact of the lone pair in lead(II) tris(pyrazolyl)methane complexes. Improved preparation of Na{B[3,5-(CF3)2C6H3]4}. Inorg. Chem. 2001, 40 (15), 3810-3814.
28. Chaney, A. L.; Marbach, E. P., Modified Reagents for Determination of Urea and Ammonia. Clin. Chem. (Winston-Salem, N. C.) 1962, 8, 130.