Norbornene polymerization using multinuclear nickel catalysts based on a polypropyleneimine dendrimer scaffold

Four multinuclear nickel complexes derived from generation 1 (G1) and generation 2 (G2) dendrimeric salicylaldimine ligands based poly(propyleneimine) dendrimer scaffolds of the type, DAB-(NH2)n (n = 4 or 8, DAB = diaminobutane) were evaluated as catalysts precursors in the polymerization of norbornene, using methylaluminoxane as co-catalyst. All four catalyst evaluated were found to be active for norbornene polymerization giving polymers with moderate to high molecular weights and low polydispersity indices. The polymerization results indicate that there is some sort of dendritic effect, in that the catalyst activity appears to be influenced by the dendrimer generation.

Graphical abstractFour novel dendritic salicylaldimine complexes of Ni were evaluated as catalyst precursors in the polymerization of norbornene. The catalysts activated by methylaluminoxane show moderate to high activity producing polynorbornenes with relatively low polydispersity indices.Figure optionsDownload full-size imageDownload as PowerPoint slide