The reaction between N, N-dimethylpropargylamine (DMPA) and a Ni(II) complex Ni(NCS)(2)(PPh(3))(2), leads to the formation of a pi-conjugated polymer (PDMPA) and to the interaction of the nickel atom of the complex with the nitrogen atoms of the pendent groups; a polymer-metal complex, PDMPA-Ni(II), is obtained. Reactions have been carried out using various complex/monomer molar ratios : the yield of the reaction and the nickel content of the polymer-metal complexes increase by increasing the amount of Ni(NCS)(2)(PPh(3))(2). Reactions of DMPA with a Rh(I) complex have also been studied for comparison; this catalyst induces only the linear polymerization of the monomer. The structure of PDMPA and of its complexes with Ni(II) has been studied by means of infra-red, nuclear magnetic resonance and X-ray photoelectron spectroscopies; a change in the stereochemistry of nickel, passing from Ni(NCS)(2)(PPh(3))(2) to the PDMPA-Ni(II) complexes, has been demonstrated.