Substituted metal carbonyls XII. Synthesis of Fe(CO)4(η1-dppf) (dppf = (Ph2PC5H4)2Fe) and its conversion into Fe2(CO)8(μ-dppf) and (CO)4Fe(μ-dppf)Mo(CO)5

Abstract

Carbonyl substitution of Fe(CO)5 by 1,1′-bis(diphenylphosphino)ferrocene (dppf) at 25° C with the aid of trimethylamine N-oxide (TMNO) gives Fe(CO)4(η1-dppf), 1, and the dinuclear triiron phosphine-bridged complex, Fe2(CO)8(μ-dppf), 2. Like dppf itself, complex 1 is a good precursor for heterometallic species, as exemplified in the synthesis of (CO)4Fe(μ-dppf)Mo(CO)5. Conversion of 1 into 2 is facile in the presence of Fe(CO)5 and TMNO. The chelate, Fe(CO)3(η2-dppf) is accessible by reaction of Fe(CO)5 with dppf and NaBH4 in n-butyl alcohol under reflux. The structures have been determined by IR, NMR (1H and 31P) and elemental analyses. © 1990.