The reaction of Pd(OAc)(2) with the bis(phosphonium) salt [Ph3PCH2COCH2PPh3]Cl-2 (1:1 molar ratio) results in the formation of the cis-dichlorobis(ylide) derivative Cl2Pd{[C(H)PPh3](2)CO}, 1, in which the bis(ylide) ligand [C(H)PPh3](2)CO acts as a chelating group through the two ylide carbon atoms. Complex 1 reacts with TlClO4 (1:1 molar ratio) to give [Pd(mu-Cl){[C(H)PPh3](2)CO}](2)(ClO4)(2), 2, which reacts with two further equivalents of TlClO4 in NCMe to give [Pd{[C(H)PPh3](2)CO}(NCMe)(2)](CLO4)(2) 3. The reactivity of 2 and 3 has been explored. Compound 2 reacts with pyridine, 3,5-lutidine, or Ph3P=C(H)CN (1:2 molar ratio), resulting in the rupture of the chlorine bridging system and formation of [PdCl{[C(H)PPh3](2)CO}(L)](ClO4) (L = py (4), 3,5-lu (5), NC-C(H)= PPh3 (6)), and with Tlacac (1:2 molar ratio) with formation of the acetylacetonate [Pd(acac){[C(H)PPh3](2)CO}](ClO4), 7. On the other hand, complex 3 reacts with the ylide Ph3P=C(H)CN (1:2 molar ratio) giving [Pd{[C(H)PPh3](2)CO}[NC-C(H)=PPh3](2)] (ClO4)(2), 8, which contains two N-coordinated ylides, and with NBu4OH (1:1) to give [Pd(mu-OH){[C(H)PPh3](2)CO}](2)(ClO4)(2), 9. The reaction of Pd(OAc)(2) with the ylide phosphonium salt [Ph3P=C(H)COCH2PPh3](ClO4) (1:1) gives the acetate dimer [Pd(mu-OOCCH3){[C(H)PPh3](2)CO}](2)(ClO4)(2), 10. The structures of complexes 1-10 were deduced from their spectroscopic data and from the resolution of the molecular structure of complex 2 . CH2Cl2.