Substitution reactions of dihydridotetracarbonyliron

Abstract

The i.r. [(ν(CO) and ν(Fe–H)] and Mössbauer spectra of H₂Fe(CO)₄ in hexane at –78 and –196° are reported. The reaction between H₂Fe(CO)₄ and thiols proceeds by simultaneous loss of hydrogen and carbon monoxide to the known thiolate-bridged complexes, [Fe(CO)₃SR]₂(R = Ph, C₆F₅, or Prⁱ). With triphenyl-phosphine and -arsine, hydrogen substitution occurs producing the complexes, Fe(CO)₄L and Fe(CO)₃L₂(L = Ph₃P or Ph₃As). Two unstable complexes were also isolated in low yield from the Ph₃As reaction, one of which was identified by mass spectrometry as Fe(CO)₄H₂AsPh₃. A structure with bridging hydrogen atoms between iron and arsenic is suggested.