Bi- and tri-dentate imino-based iron and cobalt pre-catalysts for ethylene oligo-/polymerization

Recent progress on the use of iron and cobalt complex pre-catalysts for ethylene reactivity is reviewed. The review is organized in terms of the denticity of the chelate ligands employed, with particular reference to the influence of the ligand frameworks and their substituents on the catalytic performance for ethylene oligomerization/polymerization catalysis. The majority of the systems bear tri-dentate ligation at the iron/cobalt centre, though it is clear that bi-dentate iron/cobalt complex pre-catalysts have also attracted significant attention. Such systems produce in most cases highly linear products ranging from oligomeric α-olefins to high molecular weight polyethylene, and as such are promising candidates for both academic and industrial considerations

Cationic rhodium(I) and iridium(I) α-diimine complexes

AbstractCondensation of glyoxal with fluoroarylanilines [ArFNH2; ArF=4-C6H4F; 2,4-C6H3F2; 2,4,6-C6H2F3] generates new fluorine-substituted aryl α-diimines, ArFNCHCHNArF; ArF=4-C6H4F and 2,4,6-C6H2F3 have been structurally characterised. Displacement of acetonitrile from [M(COD)(MeCN)2][BF4] (M=Rh, Ir, COD=1,5-cyclooctadiene) with fluorine- and non-fluorine-substituted aryl α-diimines yields cationic rhodium(I) and iridium(I) complexes, that can be carbonylated to [M(CO)2(α-diimine)][BF4]

Catalysis in Plastics for the 21st Century

For this Special Issue, which is part of the Organic and Polymer Chemistry Section, we would like to present the following editorial message. The Special Issue accepted manuscripts related to molecular catalysis, including metal-catalyzed polymerization of α-olefins, ring opening polymerization (ROP) of cyclic esters, acyclic diene metathesis polymerization, mechanistic studies, co-catalyst effects and DFT calculations. In this Special Issue, there is one review entitled “Synthesis of Biodegradable Polymers: A Review on the Use of Schiff-Base metal Complexes as catalysts for the Ring Opening Polymerization (ROP) of Cyclic Esters” [1]. As expected from the beginning, the scope of the catalysts covered in this issue is broad, from zirconium and hafnium to iron and cobalt-based catalysts </p