The synthesis of poly-yne polymers containing transition metals inserted in the main chain has been attempted by reacting a dialkyne molecule, 4,4'-diethynylbiphenyl (or DEBP), with [PtCl2(dppe)] and [PdCl2(dppe)], the platinum- and palladium-cis square-planar dichlorine complexes containing diphenylphosphine ethane (dppe) as bidentate ligand. The aim of this work was to obtain organometallic polymers ([Pt(dppe)DEBP](n) and [Pd(dppe)DEBP](n), respectively) having an all-cis 'zigzag' structure, by formation of a sigma -acetylide bond between the transition metal complexes and the dialkyne molecule. When [PtCl2(dppe)] was reacted with DEBP, the formation of a chlorine-terminated [Pt(dppe)DEBP], oligomer was evidenced in the reaction involving the Pd(II) complex, on the other hand, [PdCl2(dppe)] seems to catalyse the polymerisation of DEBP via opening of the triple bond, producing a poly-DEBP polymer containing Pd(II) atoms inserted in the main chain.