Potassium tetracarbonyliron hydride is the inorganic salt with the formula K[HFe(CO)4]. A pale yellow solid, it is the potassium salt of [HFe(CO)4]−, which is the conjugate base of iron tetracarbonyl dihydride:
H2Fe(CO)4 + KOH → K[HFe(CO)4] + H2O Potassium tetracarbonyliron hydride is prepared by treating iron pentacarbonyl with potassium hydroxide:
Fe(CO)5 + 2 KOH → K[HFe(CO)4] + KHCO3 Potassium tetracarbonyliron hydride is an intermediate in the synthesis of trisubstituted phosphine complexes:
K[HFe(CO)4] + 3 PBu3 + EtOH → Fe(CO)2(PBu3)3 + EtOK + 2 CO + H2
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