The reaction of Ph 2 PCH 2 PPh 2 (dppm) with ClCH 2 C(O)CH 2 Cl (1:1 molar ratio) in refluxing CHCl 3 gives the new ylide-phosphonium salt 1, through quaternization of the two P atoms of the dppm and spontaneous loss of HCl. Compound 1 reacts with NEt 3 in CHCl 3 or CH 2 Cl 2 solution (1:1 molar ratio) giving a mixture of the bis-ylide compound 2a and the ylide-methanide 2b (molar ratio 2a:2b=1:2). This mixture (prepared in situ) reacts with PdCl 2 (NCMe) 2 to give the corresponding dichloride(bis-ylide) complex 3a (coordination through the two ylidic carbons) and the dichloride(ylide-methanide) complex 3b (coordination through the ylide carbon and the methanide carbon), in a molar ratio 3a:3b=1:2. The reaction of the mixture 3a:3b with AgClO 4 (1:2 molar ratio, NCMe or Me 2 CO) in the presence of neutral ligands L gives the corresponding mixtures of the dicationic complexes [Pd(L) 2 (C,C-bis-ylide)](ClO 4 ) 2 (4a, L=NCMe; 5a, L=pyridine) and [Pd(L) 2 (C,C-ylide-methanide)](ClO 4 ) 2 (4b, L=NCMe; 5b, L=pyridine) (molar ratio 4a:4b=1:2; molar ratio 5a:5b=3:1). On the other hand, the reaction of Ph 2 PCH 2 PPh 2 (dppm) with ClCH 2 C( CH 2 )CH 2 Cl (1:1 molar ratio) in refluxing ClCH 2 CH 2 Cl gives the bis-phosphonium salt 6. This salt reacts with Li t Bu and PdCl 2 (NCMe) 2 (1:2.2:1 molar ratio) in THF affording the ylide-methanide complex 7. The crystal structures of complexes 3b.3dmso and 7.CHCl 3 have been determined by X-ray diffraction.