Living polymerization of phenylacetylenes catalyzed by cationic rhodium complexes bearing tetrafluorobenzobarrelene

Binary catalysts composed of cationic rhodium complexes, [(tfb)Rh(L) 2 ]X (tfb: tetrafluorobenzobarrelene, L: phosphine ligand, X: counter anion), and i PrNH 2 induced living polymerization of phenylacetylene and its ring-substituted derivatives. For instance, [(tfb)Rh(PPh 3 ) 2 ]BPh 4 in conjunction with i PrNH 2 polymerized phenylacetylene in a living manner to yield poly(phenylacetylene) with narrow molecular weight distribution ( M w / M n 1.09) quantitatively. The living nature was confirmed by kinetic plots of the polymerization. Nuclear magnetic resonance studies revealed that i PrNH 2 serves to dissociate the coordinating PPh 3 ligand of [(tfb)Rh(L) 2 ]X to form an initiating species. Block copolymers were synthesized by the sequential polymerization of different phenylacetylenes using the present catalyst. Binary catalysts composed of cationic rhodium complexes, [(tfb)Rh(L) 2 ]X (tfb: tetrafluorobenzobarrelene, L: phosphine ligand, X: counter anion), and i PrNH 2 induced living polymerization of phenylacetylene and its ring-substituted derivatives. The living nature was confirmed by kinetic plots of the polymerization. Nuclear magnetic resonance studies revealed that i PrNH 2 serves to dissociate the coordinating PPh 3 ligand of [(tfb)Rh(L) 2 ]X to form an initiating species. Block copolymers were synthesized by the sequential polymerization of different phenylacetylenes using the present catalyst.