bibtex: ISI:000400553000098 bibtex\location:'THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND',publisher:'ROYAL SOC CHEMISTRY',type:'Article',affiliation:'Walter, MD (Reprint Author), Tech Univ Carolo Wilhelmina Braunschweig, Inst Anorgan & Analyt Chem, Hagenring 30, D-38106 Braunschweig, Germany. Maron, L (Reprint Author), Univ Toulouse, INSA UPS LPCNO, CNRS LPCNO, 135 Ave Rangueil, F-31077 Toulouse, France. Reiners, Matthias; Maekawa, Miyuki; Daniliuc, Constantin G.; Freytag, Matthias; Jones, Peter G.; Walter, Marc D., Tech Univ Carolo Wilhelmina Braunschweig, Inst Anorgan & Analyt Chem, Hagenring 30, D-38106 Braunschweig, Germany. White, Peter S., Univ N Carolina, Dept Chem, CB 3290, Chapel Hill, NC 27599 USA. Hohenberger, Johannes; Sutter, Joerg; Meyer, Karsten, Univ Erlangen Nurnberg, Dept Chem & Pharm, Inorgan Chem, Egerlandstr 1, D-91058 Erlangen, Germany. Maron, Laurent, Univ Toulouse, INSA UPS LPCNO, CNRS LPCNO, 135 Ave Rangueil, F-31077 Toulouse, France.','author-email':'[email protected][email protected]',da:'2018-12-05','doc-delivery-number':'ET8MH',eissn:'2041-6539','funding-acknowledgement':'Alexander von Humboldt Foundation; NSF [CHE-0615704]; Emmy Noether and Heisenberg program [WA 2513/2, WA 2513/6]; Humboldt Foundation','funding-text':'We thank the Alexander von Humboldt Foundation for a Feodor-Lynen Fellowship (M. D. W.) and Prof. Maurice Brookhart for providing financial support (through NSF Grant CHE-0615704) and laboratory facilities (M. D. W.) during the initial phase of this research program. Deutsche Forschungsgemeinschaft (DFG) is acknowledged for generous funding by the Emmy Noether and Heisenberg program (WA 2513/2 and WA 2513/6, respectively). LM is grateful to the Humboldt Foundation for a grant of experienced researcher and the Chinese Academy of Science. CalMip is also gratefully acknowledged for a generous computational grant.','journal-iso':'Chem. Sci.','keywords-plus':'FE2O2 DIAMOND CORE; STRUCTURAL-CHARACTERIZATION; DINITROGEN ACTIVATION; SULFUR CLUSTERS; SOLVENT PURIFICATION; MOLECULAR-STRUCTURES; ELECTRON-TRANSFER; 2FE-2S CLUSTERS; DOUBLE-BOND; FE-IVN','number-of-cited-references':'106',oa:'DOAJ Gold','orcid-numbers':'Meyer, Karsten/0000-0002-7844-2998 Daniliuc, Constantin G./0000-0002-6709-3673','research-areas':'Chemistry','researcherid-numbers':'Meyer, Karsten/G-2570-2012 Walter, Marc/E-4479-2012','times-cited':'4','unique-id':'ISI:000400553000098','usage-count-last-180-days':'4','usage-count-since-2013':'20','web-of-science-categories':'Chemistry, Multidisciplinary'\The iron half-sandwich [Cp'Fe(mu-I)](2) (Cp' = 1,2,4-(Me3C)(3)C5H2, 1) reacts with the pseudohalides NCO-, SCN-, SeCN- and N-3(-) to give [Cp'Fe(mu-NCO)](2) (2), [Cp'Fe(mu-S)](2) (3), [Cp'Fe(mu-Se-2)](2) (4) and [Cp'Fe(mu-N)](2) (5), respectively. Various spectroscopic techniques including X-ray diffraction, solid-state magnetic susceptibility studies and Fe-57 Mossbauer spectroscopy were employed in the characterization of these species. Mossbauer spectroscopy shows a decreasing isomer shift with increasing formal oxidation state, ranging from Fe(II) to Fe(IV), in complexes 1 to 5. The sulfido-bridged dimer 3 exhibits strong antiferromagnetic coupling between the Fe(III) centers. This leads to temperature-independent paramagnetism (TIP) at low temperature, from which the energy gap between the ground and the excited state can be estimated to be 2J = ca. 700 cm(-1). The iron(IV) nitrido complex [Cp'Fe(mu-N)](2) (5) shows no reactivity towards H-2 (10 atm), but undergoes clean reactions with CO (5 bar) and XylNC (Xyl = 2,6-Me2C6H3) to form the diamagnetic isocyanate and carbodiimide complexes [Cp'Fe(CO)(2)(NCO)] (7) and [Cp'Fe(CNXyl)(2)(NCNXyl)] (8), respectively. All compounds were fully characterized, and density functional theory (DFT) computations provide useful insights into their formation and the electronic structures of complexes 3 and 5