Ethanolic Solutions of Potassium l Tetracarbonylhydridoferrate

Solutions of tetracarbonylhydridoferrate(l — ) salts can be prepared by numerous methods. The most straightforward and widely used involves the reaction of Fe(CO)s and an excess of an alkaline base in protic media. The conventional method to prepare ethanolic solutions of K[FeH(CO)J is to react Fe(CO)5 and 3 equiv of KOH in EtOH at room temperature. The procedure described here uses 2KOH equivalents only and allows the rapid and quantitative preparation of ethanolic K[FeH(CO)4] solutions, which are stable provided that all traces of oxidizing agents are rigorously excluded. 

A 60-mL ethanolic solution of K[FeH(CO)4] (11 mmol) is prepared as described above. Tri-n-butylphosphine (distilled under argon and stored 

Chemical shifts are in parts per million (ppm) downfield from external 85% H3PO4. 

The properties of the complexes Fe(CO)3L2 have been extensively studied and reviewed. Spectroscopic data are listed in Table I. 

---