Luminescent complexes a b s t r a c t Complexes [Pt(C 6 F 5 )(bzq)(CNR)] {R = t Bu (1), 2-naphthyl (2), 2,6-Me 2 Ph (3)} have been prepared by replacement of the labile acetone in [Pt(C 6 F 5 )(bzq)(Me 2 CO)] with the corresponding isocyanide ligand. The structures 1 and 3 (X-ray) confirms their square planar geometry, with the bzq ligand coplanar to the metal plane. The reactions of 1-3 toward AgClO 4 lead to the trinuclear complexes [{Pt(C 6 F 5 ) (bzq)(CNR)} 2 Ag]ClO 4 {R = t Bu (4), 2-naphthyl (5)} or the tetranuclear [{Pt(C 6 F 5 )(bzq)(CN-2,6-Me 2 Ph) Ag} 2 ](ClO 4 ) 2 (6). The structures of these three polynuclear complexes have been established by X-ray diffraction studies. Two pseudo-polymorphs of 4 (4a and 4b), only differing in the crystallization solvent, have been found. 4a/b and 5 are trinuclear Pt-Ag-Pt complexes with a ''sandwich'' disposition. In all three cases, two ''Pt(C 6 F 5 )(bzq)(CNR)'' fragments are linked by a silver atom through Pt ? Ag bonds of donor acceptor nature and the silver center establishes a short g 1 interaction with the C ipso of the bzq ligands. Furthermore, the study of the structure of 6 reveals two ''(C 6 F 5 )(bzq)(CN-2,6-Me 2 Ph)PtAg'' subunits, each containing a Pt ? Ag bond related by an inversion center and held together through g 2 interactions established by the silver atom of one unit and one of the aromatic rings of the bzq ligand of the other. The reaction of 1-3 with [Ag(OClO 3 )(PPh 3 )] produces [(C 6 F 5 )(bzq)(CNR)PtAg(PPh 3 )]ClO 4 {R = t Bu, (7), 2-naphthyl (8), 2,6-Me 2 Ph (9)}. These dinuclear clusters contain a Pt ? Ag bond and show dynamic processes in solution (NMR) which involve the rupture and formation of these interactions. The X-ray structure of 7 confirms the presence of a Pt-Ag bond and a g 1 interaction with the C ipso of the bzq ligand (2.514(6) Å). All the crystal structures determined show pÁ Á Áp interactions of the bzq which stack in a parallel fashion with interplanar distances of ca. 3.3-3.4 Å. In 5 and 6 the aromatic fragments of the isocyanide ligands also take part in these pÁ Á Áp interactions. Absorption and emission properties of all the complexes 1-9 have been studied and explained with the aid of TD-DFT theoretical calculations.Compounds 1-9 are not emissive in solution but they are in rigid matrix. In glassy 2-Me-THF or CH 2 Cl 2 at 77 K the Pt/Ag compounds 4-9 at any concentration (10 À3 M, 10 À4 M, 10 À5 M) show the same emission spectra as their corresponding starting complexes 1-3, in line with the rupture of the Pt-Ag bonds. In the solid state only the dinuclear compounds [Pt(C 6 F 5 )(bzq)(CN-t Bu)AgPPh 3 ]ClO 4 (7) and [Pt(C 6 F 5 )(bzq) (CN-2,6-Me 2 Ph)AgPPh 3 ]ClO 4 (9) together with the tetranuclear complex [{Pt(C 6 F 5 )(bzq)(CN-2,6-Me 2 Ph) Ag} 2 ](ClO 4 ) 2 (6) are emissive at room temperature showing bright greenish (7, 9) or yellowish (6) phosphorescence. In all three compounds a significant contribution of M 0 orbitals (AgPPh 3 /Ag) to the frontier orbitals (FO) has been observed, and their main emissions see...