Nickel Complexes of Guanidine Functionalized Trisiloxane

The present paper presents the preparation and characterization of Ni complex of a guanidine functionalized trisiloxane as a model compound for polysiloxanes supported metal complexes. The structures of the ligand and its Ni complex are elucidated by theoretical calculations using semi-empirical PM6 and DFT methods, and experimentally confirmed by IR, UV, NMR, SEM and EDX. Thus, a 1/1 ligand/Ni complex with a tetragonal structure was established. As proved by ATG and DSC analysis, the Ni complex is stable up to about 170 °C and is characterized by a Tg value of 25 °C in dry state. Dielectric measurements revealed a conductivity of 5.6 × 10−7 S cm−1 at 25 °C for the Ni complex, about ten times higher as compared to that of the ligand, due to the reduction of the conduction activation energy induced by the presence of the metal.