The P,N,P-tridentate ligand 2,6-bis(diphenylphosphino)pyridine, L, was employed to generate a twelve-membered metallomacrocyclic host species cis-Pt2Me4(mu-L)(2) that encapsulates TI(I) and Cu(I) guest ions. The ligand was also used to synthesize another two linear heterotrinuclear complexes, [Me2Pt(mu-L)(2)Ag-2(MeCN)(2)](BF4)(2).MeCN and [(CO)(3)Fe(mu-L)(2)Ag-2(Et2O)](ClO4)(2), both containing a metal-metal dative bond (Pt-->Ag and Fe-->Ag, respectively) and stabilized by the d(10)-d(10) argentophilic interaction.