In contrast to the facile formation of fac-[Re(CO)₃(dpk)Cl] 1 from the reaction between [Re(CO)₅Cl] and dpk [(C₅H₄N)₂C(O)], in refluxing toluene, [Re(CO)₅Cl] was recovered unchanged when di-2-pyridylamine, dpa [(C₅H₄N)₂NH], was allowed to react with [Re(CO)₅Cl] under a variety of conditions. However, a mixture of [Re(CO)₅Cl] and PPh₃ in refluxing toluene followed by a CH₂Cl₂ solution of dpa gave cis-[Re(CO)₂(PPh₃)(dpa)Cl]. The intermediate involved appears to be a general synthon for the binding of the Re^I(CO)₂(PPh₃)Cl chromophore to a variety of bi- and mono-dentate nitrogen-donor ligands and has been utilized to isolate cis-[Re(CO)₂(PPh₃)(dpk)Cl]. Nucleophilic addition of water at the carbonylic carbon atom of co-ordinated dpk in 1 and cis-[Re(CO)₂(PPh₃)(dpk)Cl] resulted in the hydration of the keto group and formation of fac-[Re(CO)₃{(C₅H₄N)₂C(O)(OH)}] and cis-[Re(CO)₂(PPh₃){(C₅H₄N)₂C(O)(OH)}]. The compounds isolated exhibit rich electrochemical and photochemical properties and the potential application of fac-[Re(CO)₃(dpk)Cl] as an electrochemical sensor for electrophiles and Group I and II metal ions is demonstrated.