Adducts of the diphosphine cis-Ph2P(CHCH)PPh2 (L) with AgX (X = NO3, BF4, ClO4 or CF3SO3) have been synthesized and characterized both in solution (1H, 31P NMR) and in the solid state (IR, single crystal X-ray structure analysis). The topologies of the structures in the solid state were found to depend on the nature of the counter-ion X. The adduct AgNO3:L (2:1)2 is tetranuclear, derivative of the chair form, the bidentate ligands bridging peripheral silver centers, the nitrates being coordinated through two oxygen atoms, the first O,O′-bridging the second bridging bidentate.