Synthesis of a novel phosphate-containing ligand rhodium catalyst and exploration of its optimal reaction conditions and mechanism for the polymerization of phenylacetylene

Due to the chemical properties of Group VIII transition metals and their importance in catalytic processes, the reactions of rhodium and its neighboring organic complexes have received much attention as model systems. In the present experiments, we successfully prepared two new rhodium complexes named [Rh(cod)(TTP)Cl] and [Rh(cod)(CDP)Cl] using tri(o-tolyl)phosphine and clohexyldiphenylphosphine as ligands, respectively, and the proofs of their structures were completed using 1H NMR and 13C NMR. Subsequently, it was applied to the polymerization reaction of phenylacetylene (PA), and the effects of different solvents, time, and temperature on the yield and molecular weight of the polymerization reaction products were discussed. The experimental results show that both complexes can play a catalytic role in the polymerization of PA. From the point of view of polymer molecular weight, the best reaction conditions for both catalysts were 3 h at 20°C in THF solvent (molecular weight up to 2.40 × 105). From the point of view of yield, the best reaction conditions for both catalysts were 4 h at 35°C in THF solvent (yield up to 89.2%).