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A new rhodium complex [Rh(cod)(TTT)2] was synthesized by [Rh(cod)Cl]2 as a precursor, and 4,4',4''-(1,3,5-triazine-2,4,6-triyl)trianiline (TTT) as a ligand. Its structure was verified by 1H and 13C NMR. The results indicate that the complex shows high activity in phenylacetylene polymerization. It was applied to the polymerization of phenylacetylene with a yield of 45.0% and Mw = 2.26×105 at ultra-low rhodium feed ratio ([Rh.]/[M.]=1/60000). A new rhodium complex [Rh(cod)(TTT)2] was synthesized by [Rh(cod)Cl]2 as a precursor, and 4,4',4''-(1,3,5-triazine-2,4,6-triyl)trianiline (TTT) as a ligand. It was applied to the polymerization of phenylacetylene with a yield of 45.0% and Mw = 2.26×105 at ultra-low rhodium feed ratio ([Rh.]/[M.]=1/60000 [ABSTRACT FROM AUTHOR]

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%).

Three novel rhodium complexes, with l-tyrosine (l-Tyr), l-arginine (l-Arg), or 2,4-diamino-6-phenyl-1,3,5-triazine (Dpt) as a ligand, named as [Rh(cod)(l-Tyr)], [Rh(cod)(l-Arg)], and [Rh(cod)(Dpt)2], respectively, had been synthesized for catalyzing the polymerization of phenylacetylene. Their yields were 62.34, 54.87, and 58.21%, respectively, by the most suitable synthesis conditions at 25°C for 4 h. The structures and purity of these complexes were proved by 1H NMR, element analysis, and scanning electron microscope (SEM). It has been examined that phenylacetylene could be polymerized by the three complexes as catalysts with high degrees of polymerization (n = 368, 385, and 664, respectively) and yields (about 87.62, 88.39, and 59.67%, respectively). In conclusion, compared with traditional [Rh–N] type catalysts, the novel [N–Rh–N] type catalyst ([Rh(cod)(Dpt)2]) gained better catalytic performance. By comparing the yield, Mw, and degree of their polymerization, the polymerization mechanism was found under the [N–Rh–N] type rhodium catalyst system.