The reaction of PEt₂OH with K₂PtCl₄ yields [PtCl{(PEt₂O)₂H}]₂ (2). The X-ray crystal structure of 2 shows that the two chloride ligands bridge the two Pt atoms. The structure is unusual in that the PtCl₂Pt unit is bent, which is the first example of a platinum phosphinito chloride-bridged dimer that is bent. Dimer 2 is a poor catalyst for the hydration of acetonitrile (and presumably other nitriles). Likewise, the monomeric catalyst that results from the reaction of 2 with sodium hydroxide is not a good hydration catalyst. In an attempt to form a more reactive monomeric catalyst, PtCl(PMe₂OH){(PMe₂O)₂H} (1) was reacted with sodium hydroxide. This reaction resulted in the formation of two species, tentatively characterized as Na[PtCl(PMe₂O){(PMe₂O)₂H}] (5) and Na[PtCl(OH){(PMe₂O)₂H}] (6). Complexes 5 and 6 could not be separated. However, the mixture of the two complexes quickly hydrated acetonitrile. The catalyst mixture of 5 and 6 was efficiently poisoned by cyanide, which prevented its use as a catalyst for the hydration of cyanohydrins.