The reversible redox transformations [(NO)2Fe(StBu)2]– [Fe(-StBu)(NO)2]22– (2) [Fe(-StBu)(NO)2]2– [Fe(-StBu)(NO)2]2 are demonstrated. The binding preference of ligands [OPh]–/[SR]– toward the {Fe(NO)2}10-{Fe(NO)2}10 motif of dianionic reduced RRE follows the ligand-displacement series [SR]–＞[OPh]–, rationalizing that most of the DNICs and RREs characterized nowadays are bound to protein via cysteinate side chains. Compared to the Fe K-edge pre-edge energy falling within the range of 7113.6-7113.8 eV for the dinuclear {Fe(NO)2}9-{Fe(NO)2}9 DNICs and 7113.4-7113.8 eV for the mononuclear {Fe(NO)2}9 DNICs, the {Fe(NO)2}10 reduced DNICs and the {Fe(NO)2}10-{Fe(NO)2}10 dianionic reduced RREs containing S-/O-/N-ligation modes display the characteristic pre-edge energy 7113.1-7113.3 eV, which may be adopted to probe the formation of the EPR-silent {Fe(NO)2}10-{Fe(NO)2}10 dianionic reduced RREs and {Fe(NO)2}10 dianionic reduced monomeric DNICs in biology. In addition to the characteristic Fe/S K-edge pre-edge energy, the IR νNO spectra may also be adopted to characterize and discriminate [(NO)2Fe(-StBu)]2 (IR νNO 1809 vw, 1778 s, 1753 s cm-1 (KBr)), [Fe(-StBu)(NO)2]2– (IR νNO 1674 s, 1651 s cm-1 (KBr)), and [Fe(-StBu)(NO)2]22– (IR νNO 1637 m, 1613 s, 1578 s, 1567 s cm-1 (KBr)). Additionally, The fluxional terminal and semibridging NO-coordinate ligands of DNIC [Fe4(-S)2(-NO)2(NO)6]2– (3), a precursor of Roussin’s black salt (RBS), are characterized by IR NO), 15N(NO) NMR, single-crystal X-ray diffraction, and DFT calculations. Compared to the {Fe(NO)2}9 and {Fe(NO)2}10 DNICs/RREs displaying 15N (NO) NMR chemical shift (23 ~ 76 ppm) and (-7.8 ~ 25 ppm), respectively, the first semibridging nitroxyl of complex 3 exhibits the distinct 15N (NO) NMR chemical shift (200.8 and 200.1 ppm), suggesting the 15N (NO) NMR technique can serve as an efficient tool to discriminate the binding fashions of NO. In the last part, the stable {Fe(NO)2}10 reduced DNICs [(NO)2Fe(S(CH2)nS)]2– [ n = 3 (4); n = 2 (5) ] containing chelate dithiolate were synthesized. On the basis of the electrochemistry, and DFT calculations of 4 and 5, the bite angle or ring strain inherent in the chelate-dithiolate-bound DNICs will function to tune the Fe-S bonding level, so as to modulate the configurations and electrochemical properties of DNICs (E1/2 = -1.64 V for 4 and E1/2 = -1.33 V for 5). The dithiolate ligands are also introduced to build [(NO)2Fe(-2-SC2H4S)(-NO)Fe(NO)]2– (7) bearing a bridging NO as well as the fluxional isomers of [(NO)2Fe(-2-SC3H6S)(-NO)Fe(NO)]2– (8-a) and [(NO)2Fe(-SC3H6S)Fe(NO)2]2– (8-b). Intriguingly, the electrochemical studies demonstrate that complex 7, resembling to the calculated double-reduced intermediate [(CO)3Fe(-2-edt)(-CO)Fe(CO)2]2– of [FeFe]-H2ase model, act as an active molecular electrocatalyst for proton reduction from weak acid with low overpotential.

References
1. (a) Pacher, P.; Beckman, J. S.; Liaudet, L. Physiol. Rev. 2007, 87, 315. (b) Szaciłowski, K.; Chmura, A.; Stasicka, Z. Coord. Chem. Rev. 2005, 249, 2408.
2. Koshland, D. E. Science 1992, 258, 1861.
3. (a) Furchgott, R. F.; Zawadski, J. V. Nature 1980, 288, 373. (b) Palmer, R. M. J.; Ferrige, A. G.; Moncada, S. Nature. 1987, 327, 524. (c) Ignarro, L. J.; Buga, G. M.; Wood, K. S.; Byrns, R. E.; Chaudhuri, G. Proc. Natl. Acad. Sci. 1987, 84, 9265.
4. Marletta, M. A. Cell 1994, 78, 927.
5. (a) Henry, Y.; Ducrocq, C.; Drapier, J. C.; Servent, D.; Pellat, C.; Guissani, A. Eur. Biophys. J. 1991, 20, 1. (b) Moncada, S.; Palmer, R. M. J.; Higgs, E. A. Pharmacol. Rev. 1991, 43, 109. (c) Davis, K. L.; Martin, E.; Turko, I. V.; Murad, F. Annu. Rev. Pharmacol. Toxicol. 2001, 41, 203. (d) Posen, G. M.; Tsai, P.; Pou, S. Chem. Rev. 2002, 102, 1191. (e) Bogdan, C. Trends Cell Biol. 2001, 11, 66.
6. (a) Bryan, N. S.; Rassaf, T.; Maloney, R. E.; Rodriguez, C. M.; Saiji, F.; Rodriguez, J. R.; Feelisch, M. Proc. Natl. Acad. Sci. 2004, 101, 4308. (b) Rassaf, T.; Bryan, N. S.; Kelm, M.; Feelisch, M. Free Radic. Biol. Med. 2002, 33, 1590.
7. (a) Lundberg, J. O.; Weitzberg, E.; Cole, J. A.; Benjamin, N. Nat. Rev. Microbiol. 2004, 2, 593. (b) Lundberg, J. O.; Weitzberg, E.; Gladwin M. T. Nat. Rev. Drug Discovery 2008, 7, 156.
8. (a) Zhiqiang, C.; Stamler, J. S. Trends Cardiovasc. Med. 2006, 16, 259. (b) Wenzel, P.; Hink, U.; Oelze, M.; Schuppan, S.; Schaeuble, K.; Schildknecht, S.; Ho, K. K.; Weiner, H.; Bach-schmid, M.; Münzel, T.; Daiber, A. J. Biol. Chem. 2007, 282, 792.
9. Hess, D. T.; Matsumoto, A.; Kim, S.-O.; Marshall, H. E.; Stamler, J. S. Nat. Rev. Mol. Cell Biol. 2005, 6, 150.
10. (a) Luchsinger, B. P.; Rich, E. N.; Gow, A. J.; Williams, E. M.; Stamler, J. S.; Singel, D. J. Proc. Natl. Acad. Sci. U.S.A. 2003, 100, 461. (b) Stamler, J. S.; Jia, L.; Eu, J. P.; McMahon, T. J.; Demchenko, I. T.; Bonaventura, J.; Gernert, K.; Piantadosi, C. A. Science 1997, 276, 2034. (c) Pawloski, J. R.; Hess, D. T.; Stamler, J. S. Nature 2001, 409, 622.
11. (a) Boese, M.; Keese, M. A.; Becker, K.; Busse, R.; Mülsch, A. J. Biol. Chem. 1997, 272, 21767. (b) Lee, M.; Arosio, P.; Cozzi, A.; Chasteen, M. D. Biochemistry 1994, 33, 3679.
12. (a) Boese, M.; Mordvintcev, P. I.; Vanin, A. F.; Busse, R.; Mülsch, A. J. Biol. Chem. 1995, 270, 29244. (b) Kim, Y.-M.; Chung, H.-T.; Simmons, R. L.; Billiar, T. R. J. Biol. Chem. 2000, 275, 10954. (c) D’Autréaux, B.; Horner, O.; Oddou, J.-L.; Jeandey, C.; Gambarelli, S.; Berthomieu, C. ; Latour, J.-M. ; Michaud-Soret, I. J. Am. Chem. Soc. 2004, 126, 6005. (d) Severina, I. S.; Bussygina, O. G.; Pyatakova, N. V.; Malenkova, I. V.; Vanin, A. F. Nitric Oxide 2003, 8, 155. (e) Wiegant, F. A. C.; Malyshev, I. Y.; Kleschyov, A. L.; van Faassen, E.; Vanin, A. F. FEBS Lett. 1999, 455, 179. (f) Malyshev, I. Y.; Malugin, A. V.; Golubeva, L. Y.; Zenina, T. A.; Manukhina, E. B.; Mikoyan, V. D.; Vanin, A. F. FEBS Lett. 1996, 391, 21. (g) Cesareo, E.; Parker, L. J.; Pedersen, J. Z.; Nuccetelli, M.; Mazzetti, A. P.; Pastore, A.; Federici, G.; Caccuri, A. M.; Ricci, G.; Adam, J. J.; Parker, M. W.; Bello, M. L. J. Biol. Chem. 2005, 280, 42172.
13. (a) Foster, M. W.; Hess, D. T.; Stamler, J. S. Trends Mol. Med. 2009, 15, 391. (b) Hess, D. T.; Matusmoto, A.; Kim, S.-O.; Marshall, H. E.; Stamler, J. S. Nat. Rev. Mol. Cell Biol. 2005, 6, 150. (c) Foster, M. W.; McMahon, T. J.; Stamler, J. S. Trends Mol. Med. 2003, 9, 160.
14. Watts, R. N.; Hawkins, C.; Ponka, P.; Richardson, S. R. Proc. Natl. Acad. Sci. U.S.A. 2006, 103, 7670.
15. (a) Stamler, J. S.; Singel, D. J.; Loscalzo, J. Science 1992, 258, 1898. (b) Stamler, J. S. Cell 1994, 78, 931.
16. (a) Hess, D.T.; Matusmoto, A.; Kim, S. O.; Marshall, H. E.; Stamler, J. S. Nat. Rev. Mol. Cell Biol. 2005, 6, 150. (b) Foster, M. W.; Hess, D.T.; Stamler, J. S. Trends Mol. Med. 2009, 15, 391.
17. (a) Friebe, A.; Koesling, D. Circ. Res. 2003, 93, 96. (b) Evgenov, O. V.; Pacher, P.; Schmidt, P. M.; Haskó, G.; Schmidt, H. H. H. W.; Stasch J.-P. Nat. Rev. Drug Discovery 2006, 5, 755.
18. (a) Lewandowska, H.; Męczyʼnska, S.; Sochanowicz, B.; Sadło, J.; Kruszewaji, M. J. Biol. Inorg. Chem. 2006, 444,444. (b) Kim, Y.-M.; Chung, H.-T.; Simmons, R. L.; Billiar, T. R. J. Biol. Chem. 2000, 275, 10954. (c) Kim, S.; Ponka, P. Proc. Natl. Acad. Sci. 2002, 99, 12214.
19. Autreaux, B. D.; Tucker, N. P.; Dixon, R.; Spiro, S. Nature, 2005, 437, 769.
20. (a) Calzolai, L.; Zhou, Z.-H.; Adams, M. W. W.; Lamar, G. N. J. Am. Chem. Soc. 1996, 118, 2513. (b) Flint, D. H.; Allen, R. M. Chem. Rev. 1996, 96, 2315. (c) Beinert, H.; Kennedy, M. C.; Stout, C. D. Chem. Rev. 1996, 96, 2335. (d) Dobbek, H.; Svetlitchnyi, V.; Gremer, L.; Huber, R.; Meyer, O. Science 2001, 293, 1281. (e) Berkovitch, F.; Nicolet, Y.; Wan, J. T.; Jarrett, J. T.; Drennan, C. L. Science 2004, 303, 76.
21. (a) Rouault, T. A.; Tong, W.-H. Nat. Re V . Mol. Cell Biol. 2005, 6, 345. (b) Balk, J.; Lill, R. ChemBioChem 2004, 5, 1044. (c) Gerber, J.; Lill, R. Mitochondrion 2002, 2, 71. (d) Fontecave, M.; Ollagnier-de Choudens, S. Arch. Biochem. Biophys. 2008, 474, 226.
22. Kennedy, M. C.; Antholone, W. E.; Beinert, H. J. Biol. Chem. 1997, 272, 20340.
23. Pomposiello P. J.; Demple, B. Trends Biotechnol. 2001, 19, 109.
24. (a) Ding, H.; Demple, B. Proc. Natl. Acad. Sci. 2000, 97, 5146. (b) Yang, W.; Rogers, P. A.; Ding, H. J. Biol. Chem. 2002, 277, 12868.
25. (a) Roger, P. A.; Ding, H. J. Biol. Chem. 2001, 276, 30980-30986. (b) Yang, W.; Roger, P. A.; Ding, H. J. Biol. Chem. 2002, 277, 12868-12873. (c) Rogers, P. A.; Eide, L.; Klungland, A.; Ding, H. DNA Repair 2003, 2, 809.
26. (a) Sellers, V. M.; Johnson, M. K.; Dailey, H. A. Biochemistry 1996, 35, 2699. (b) Cruz-Ramos, H.; Crack, J.; Wu, G.; Hughes, M. N.; Scott, C.; Thomson, A. J.; Green, J.; Poole, R. K. EMBO J. 2002, 21, 3235. (c) Welter, R.; Yu, L.; Yu, C. A. Arch. Biochem. Biophys. 1996, 331, 9. (d) Goussias, C.; Deligiannakis, Y.; Sanakis, Y.; Ioannidis, N.; Petrouleas, V. Biochemistry 2002, 41, 15212.
27. Vithayathil, A. J.; Ternberg, J.L.; Commoner, B. Nature 1965, 207, 1246.
28. Enemark, J. H.; Feltham, R. D. Coord. Chem. Rev. 1974, 13, 339.
29. (a) Franz, K. J.; Lippard, S. J. J. Am. Chem. Soc. 1998, 120, 9034. (b) Brown, C. A.; Pavlosky, M. A.; Westre, T. E.; Zhang, Y.; Hedman, B.; Hodgson, K. O.; Solomen, E. I. J. Am. Chem. Soc. 1995, 117, 715.
30. Wang, J.-H.; Chen, C.-H. Inorg. Chem. 2010, 49, 7644.
31. (a) Mokh, V. P.; Poltorakov, A. P.; Serezhenkov, V. A.; Vanin, A. F. Nitric Oxide 2010, 22, 266. (b) Chen,Y.-J.; Ku, W.-C.; Feng, L.-T.; Tsai, M.-L.; Hsieh, C.-H.; Hsu, W.-H.; Liaw, W.-F.; Hung, C.-H.; Chen, Y.-J. J. Am. Chem. Soc. 2008, 130, 10929.
32. (a) Tsai, M.-L.; Hsieh, C.-H.; Liaw, W.-F. Inorg. Chem. 2007, 46, 5110. (b) Tsai, M.-L.; Liaw, W.-F. Inorg. Chem. 2006, 45, 6583.
33. (a) Thomas, J. T.; Robertson, J. H.; Cox, E. G. Acta Crystallogr. 1958, 11, 599. (b) Harrop, T. C.; Song, D. T.; Lippard, S. J. J. Am. Chem. Soc. 2006, 128, 3528.
34. (a) Tsou, C.-C.; Lu, T.-T.; Liaw, W.-F. J. Am. Chem. Soc. 2007, 129, 12626. (b) Lu, T.-T.; Tsou, C.-C.; Huang, H.-W.; Hsu, I.-J.; Chen, J.-M.; Kuo, T.-S.; Wang, Y.; Liaw, W.-F. Inorg. Chem. 2008, 47, 6040.
35. (a) Tinberg, C. E.; Tonzetich, Z. J.; Wang, H.; Do, L. H.; Yoda, Y.; Cramer, S. P.; Lippard, S. J. J. Am. Chem. Soc. 2010, 132, 18168. (b) Tonzetich, Z. J.; Wang, H.; Mitra, D.; Tinberg, C. E.; Do, L. H.; Jenney, F. E., Jr.; Adams, M. W. W.; Cramer, S. P.; Lippard, S. J. J. Am. Chem. Soc. 2010, 132, 6914. (c) Crack, J. C.; Smith, L. J.; Stapleton, M. R.; Peck, J.; Watmough, N. J.; Buttner, M. J.; Buxton, R. S.; Green, J. G.; Oganesyan, V. O.; Thomson, A. J.; Le Brun, N. E. J. Am. Chem. Soc. 2011, 133, 1112.
36. (a) Tsai, M.-L.; Chen, C.-C.; Hsu, I.-J.; Ke, S.-C.; Hsieh, C.-H.; Chiang, K.-A.; Lee, G.-H.; Wang, Y.; Liaw, W.-F. Inorg. Chem. 2004, 43, 5159. (b) Tsai, F.-T.; Chiou, S. J.; Tsai, M.-C.; Tsai, M.-L.; Huang, H.-W.; Chiang, M.-H.; Liaw, W.-F. Inorg. Chem. 2005, 44, 5872. (c) Tsai, M.-L.; Liaw, W.-F. Inorg. Chem. 2006, 45, 6583. (d) Hung, M.-C.; Tsai, M.-C.; Lee, G.-H.; Liaw, W.-F. Inorg. Chem. 2006, 45, 6041. (e) Lu, T.-T.; Chiou, S.-J.; Chen, C.-Y.; Liaw, W.-F. Inorg. Chem. 2006, 45, 8799. (f) Chen, T.-N.; Lo, F.-C.; Tsai, M.-L.; Shih, K.-N.; Chiang, M.-H.; Lee, G.-H.; Liaw, W.-F. Inorg. Chim. Acta 2006, 359, 2525. (g) Chiou, S.-J.; Wang, C.-C.; Chang, C.-M. J. Organomet. Chem. 2008, 693, 3582. (h) Huang, H.-W.; Tsou, C.-C.; Kuo, T.-S.; Liaw, W.-F. Inorg. Chem. 2008, 47, 2196. (i) Tsai, M.-C.; Tsai, F.-T.; Lu, T.-T.; Tsai, M.-L.; Wei, Y.-C.; Hsu, I.-J.; Lee, J.-F.; Liaw, W.-F. Inorg. Chem. 2009, 48, 9579. (j) Albano, V. G.; Araneo, A.; Bellon, P. L.; Chani, G.; Manassero, M. J. Organomet. Chem. 1974, 67, 413.
37. (a) Tsou, C.-C.; Lin, Z.-S.; Lu, T.-T.; Liaw, W.-F. J. Am. Chem. Soc. 2008, 130, 17154. (b) Lu, T.-T.; Huang, H.-W.; Liaw, W.-F. Inorg. Chem. 2009, 48, 9027.
38. Lu, T.-T.; Chen, C.-H.; Liaw, W.-F. Chem. Eur. J. 2010, 16, 8088.
39. Tsou, C.-C.; Liaw, W.-F. Chem. Eur. J. 2011, 17, 13358.
40. (a) Frey, M. ChemBioChem 2002, 3, 153. (b) Evans, D. J.; Pickett, C. J. Chem. Soc. Rev. 2003, 32, 268.
41. (a) Peters, J. W.; Lanzilotta, W. N.; Lemon, B. J.; Seefeldt, L. C. Science 1998, 282, 1853. (b) Nicolet, Y.; de Lacey, A. L.; Vernede, X.; Fernandez, V. M.; Hatchikian, C.; Fontecilla-Camps, J. C. J. Am. Chem. Soc. 2001, 123, 1596.
42. (a) Gloaguen, F.; Lawrence, J. D.; Rauchfuss, T. B. J. Am. Chem. Soc. 2001, 123, 9476. (b) Chong, D.; Georgakaki, I. P.; Mejia-Rodriguez, R.; Sanabria-Chinchilla, J.; Soriaga, M. P.; Darensbourg, M. Y. Dalton Trans. 2003, 4158. (c) Mejia-Rodriguez, R.; Chong, D.; Reibenspies, J. H.; Soriaga, M. P.; Darensbourg, M. Y. J. Am. Chem. Soc. 2004, 126, 12004. (d) Duan, L.; Wang, M.; Li, P.; Na, Y.; Wang, N.; Sun, L. Dalton Trans. 2007, 1277. (e) Song, L.-C.; Yang, Z.-Y.; Bian, H.-Z.; Liu, Y.; Wang, H.-T.; Liu, X.-F.; Hu, Q.-M. Organometallics 2005, 24, 6126. (f) Song, L.-C.; Ge, J.-H.; Zhang, X.-G.; Liu, Y.; Hu, Q.-M. Eur. J. Inorg. Chem. 2006, 3204. (g) Wang, M.; Chen, L.; Sun, L. Energy Environ. Sci. 2012, 5, 6763. (h) Felton, G. A. N.; Mebi, C. A.; Petro, B. J.; Vannucci, A. K.; Evans, D. H.; Glass, R. S.; Lichtenberger, D. L. J. Organomet. Chem. 2009, 694, 2681.
43. (a) Felton, G. A. N.; Vannucci, A. K.; Chen, J.; Lockett, L. T.; Okumura, N.; Petro, B. J.; Zakai, U. I.; Evans, D. H.; Glass, R. S.; Lichtenberger, D. L. J. Am. Chem. Soc. 2007, 129, 12521. (b) Chen, J.; Vannucci, A. K.; Mebi, C. A.; Okumura, N.; Borowski, S. C.; Swenson, M.; Lockett, L. T.; Evans, D. H.; Glass, R. S.; Lichtenberger, D. L. Organometallics 2010, 29, 5330.
44. Felton, G. A. N.; Petro, B. J.; Glass, R. S.; Lichtenberger, D. L.; Evans, D. H. J. Am. Chem. Soc. 2009, 131, 11290.
45. Mason, J.; Larkworthy, L. F.; Moore, E. A. Chem. Rev. 2002, 102, 913.
46. P. Chen, D. E. Root, C. Campochiaro, K. Fujisawa and E. I. Solomon, J. Am. Chem. Soc. 2003, 125, 466.
47. O. Kahn, Molecular Magnetism; VCH Publishers: New York, 1993; pp 103
48. (a) Felton, G. A. N.; Glass, R. S.; Lichtenberger, D. L.; Evans, D. H. Inorg. Chem. 2006, 45, 9181. (b) Fourmond,V.; Jacques, P.-A.; Fontecave, M.; Artero, V. Inorg. Chem. 2010, 49, 10338. (c) Connelly, N. G.; Geiger, W. E. Chem. Rev. 1996, 96, 877.
49. (a) Pool, D. H.; DuBois, D. L. J. Organomet. Chem. 2009, 694, 2858. (b) Kilgore, U. J.; Roberts, J. A. S.; Pool, D. H.; Appel, A. M.; Stewart, M. P.; DuBois, M. R.; Dougherty, W. G.; Kassel, W. S.; Bullock, R. M.; DuBois, D. L. J. Am. Chem. Soc. 2011, 133, 5861.
50. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, J. A., Jr.; Vreven, T.; Kudin, K. N.; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.; Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. G.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; Pople, J. A., Gaussian 09.
51. (a) Becke, A. D. Phys. Rev. A 1988, 38, 3098. (b) Perdew, J. P. Phys. Rev. B 1986, 33, 8822.
52. Kaupp, M.; Schleyer, P. V. R.; Stoll, H.; Preuss, H. J. Chem. Phys. 1991, 94, 1360.
53. (a) Krishnan, R.; Binkley, J. S.; Seeger, R.; Pople, J. A. J. Chem. Phys. 1980, 72, 650. (b) Wachters, A. J. H. J. Chem. Phys. 1970, 52, 1033. (c) Hay, P. J. J. Chem. Phys. 1977, 66, 4377.
54. Brothers, S. M.; Darensbourg, M. Y.; Hall, M. B. Inorg. Chem. 2011, 50, 8532.
55. Miertus, S.; Scrocco, E.; Tomasi, J. Chem. Phys. 1981, 55, 117.
56. (a) Glaser, T.; Hedman, B.; Hodgson, K. O.; Solomon, E. I. Acc. Chem. Res. 2000, 33, 859. (b) Solomon, E. I.; Hedman, B.; Hodgson, K. O.; Dey, A.; Szilagyi, R. K. Coord. Chem. Rev. 2005, 249, 97. (c) Rose, K.; Shadle, S. E.; Eidsness, M. K.; Kurtz, D. M., Jr.; Scott, R. A.; Hedman, B.; Hodgson, K. O.; Solomon, E. I. J. Am. Chem. Soc. 1998, 120, 10743.
57. Sheldrick, G. M. SADABS; University of Göttingen: Göttingen, Germany, 1996.
58. Sheldrick, G. M. SHELXTL; Siemens Analytical X-ray InstrumentsInc.: Madison, WI, 1994.
59. Tsou, C.-C.; Tsai, F.-T.; Chen, H.-Y.; Hsu, I.-J.; Liaw, W.-F. Inorg. Chem. 2013, 52, 1631.
60. Lin, Z.-S.; Chiou, T.-W.; Liu, K.-Y.; Hsieh, C.-C.; Yu, J.-S. K.; Liaw, W.-F. Inorg. Chem. 2012, 51, 10092.
61. T. Hayashi, J. D. Caranto, H. Matsumura, D. M. Jr. Kurtz and P. Moënne-Loccoz, J. Am. Chem. Soc. 2012, 134, 6878.
62. Horrocks Jr, W. D.; Taylor, R. C. Inorg. Chem. 1963, 2, 723.
63. (a) Zaffaroni, R.; Rauchfuss, T. B.; Gray, D. L.; Gioia, L. De; Zampella, G. J. Am. Chem. Soc. 2012, 134, 19260. (b) Ezzaher, S.; Gogoll, A.; Bruhn, C.; Ott, S. Chem. Commun. 2010, 46, 5775. (c) Liu, Y.-C.; Chu, K.-T.; Jhang, R.-L.; Lee, G.-H.; Chiang, M.-H. Chem. Commun. 2013, 49, 4743.
64. (a) DuBois, J. L.; Mukherjee, P.; Stack, T. D. P.; Hedman, B.; Solomon, E. I.; Hodgson, K. O. J. Am. Chem. Soc. 2000, 122, 5775. (b) Westre, T. E.; Kennepohl, P.; Dewitt, J. G.; Hedman, B.; Hodgson, K. O.; Solomon, E. I. J. Am. Chem. Soc. 1997, 119, 6297.
65. (a) Glaser, T.; Rose, K.; Shadle, S. E.; Hedman, B.; Hodgson, K. O.; Solomon, E. I. J. Am. Chem. Soc. 2001, 123, 442. (b) Shadle, S. E.; Hedman, B.; Hodgson, K. O.; Solomon, E. I. Inorg. Chem. 1994, 33, 4235. (c) Sun, N.; Liu, L. V.; Dey, A.; Villar-Acevedo, G.; Kovacs, J. A.; Darensbourg, M. Y.; Hodgson, K. O.; Hedman, B.; Solomon, E. Inorg. Chem. 2011, 50, 427. (d) Shadle, S. E.; Hedman, B.; Hodgson, K. O.; Solomon, E. I. J. Am. Chem. Soc. 1995, 117, 2259. (e) Lu, T.-T.; Lai, S.-H.; Li, Y.-W.; Hsu, I.-J.; Jang, L.-Y.; Lee, J.-F.; Chen, I.-C.; Liaw, W.-F. Inorg. Chem. 2011, 50, 5396.