The cyclometallated Pd compound PdCl[PPh₂CH₂CH₂CHCH₂CH₂PPh₂] 1, obtained from PdCl₂(Ph₂P(CH₂)₅PPh₂) in refluxing DMF (N,N-dimethylformamide), was characterized by NMR and X-ray single-crystal diffraction analysis. The cyclometallation of MCl₂(Ph₂P(CH₂)₅PPh₂)(M = Pd, Pt) to give 1 and its Pt(II) analogue was probed using electrospray ionisation mass spectrometry (ESMS). The reactivity of 1 towards neutral ligands such as phosphines and pyridines as well as basic metal complexes such as pyridine-thiolate compounds of Au(I), Hg(II) and Pt(II) in solution was also investigated. The results showed that the chloride trans to the Pd–C bond is susceptible to ligand replacement. A number of entry metalloligands was examined in an attempt to establish a route to cyclometallated aggregates and clusters.