Laurence D. Rosenhein

Synthesis and structure of [NEt4]Fe(CO)3(μ-SPh)2Mo(CO)3(SPh): A heterodinuclear compound with bridging and terminal thiolate ligands

Abstract A new heterodinuclear compound, [NEt4]Fe(CO)3(μ-SPh)2Mo(CO)3(SPh), has been prepared from the reaction of Fe(CO)4Br2 with [NEt4]SPh and molybdenum carbonyl starting materials. The compound has been characterized spectroscopically and by X-ray diffraction.

Synthesis of cis- and trans-Fe(CyNC)4(SPh)2: bis-thiolate precursors of the mixed-metal complex, (CyNC)4Fe(SPh)2Mo(CO)4

Abstract Reaction of [Et 4 N] 2 [Fe(SPh) 4 ] with CyNC in MeCN yields cis - and trans -Fe(CyNC) 4 (SPh) 2 which have been identified by their IR spectral data and physical properties. The less-soluble trans isomer converts spontaneously into its cis analog in MeCN by a first order process with k obs = 1.5 x 10 −4 s −1 at 20°C. Cyclic voltammetry studies show that the trans isomer undergoes clean, pseudoreversible, one-electron oxidation with E 1 2 = −0.28 V, while cis -Fe(CyNC) 4 (SPh) 2 is oxidized in a multistep, irreversible process at more positive potentials. Both forms of Fe(CyNC) 4 (SPh) 2 react with the substitution-labile carbonylmolybdenum(0) species, (norbornadiene)Mo(CO) 4 , to generate the new binuclear mixed-metal complex (CyNC) 4 Fe(SPh) 2 Mo(CO) 4 . Cyclic voltammetry of the hetereometallic species shows two pseudoreversible oxidative redox events which formally correspond to Fe II /Fe III and Mo 0 /Mo I couples.

Structural changes upon oxidation of a linear, trinuclear iron-molybdenum complex

Abstract The previously-reported compounds, [NEt4]4Mo[(CO)4]2Fe(SPh)4 (1) and [Mo(CO)4]2Fe(SPh)4 (2), which are related by two-electron oxidation and reduction, have been structurally characterized by low-temperature X-ray diffraction. Both are linear compounds, differing principally by the presence in 2 of two iron-molybdenum bonds. The FeMo distances in 1 are 3.362(1) and 3.440(1) A, while in 2 they are 2.748(1) and 2.793(1) A.