Amidinate group 4 complexes in the polymerization of olefins

Abstract

The current perspective will present the use of amidinate group 4 complexes in α-olefin polymerizations. We will present the structural studies of the complexes bearing various numbers of amidinates as spectator ligands, with a special emphasis on the bisIJamidinate) group 4 systems. The mechanistic studies elucidate the influence of various reaction conditions on the behaviour of the reactive species. Additionally, the study of the active species by techniques such as EPR spectroscopy and MALDI-TOF spectrometry are presented. We will also demonstrate how, based on such techniques, highly stereospecific bis(amidinate) titanium complexes may be designed and applied in the polymerization of propylene.

N-Heterocyclic carbene–carbodiimide (NHC–CDI) betaine adducts: synthesis, characterization, properties, and applications

“…Amidinates are p-electron rich chelating ligands, whose coordination chemistry has been extensively studied across the periodic table. [17][18][19][20][21][22] These complexes have seen applications in homogenous catalysis 46 (in particular, olen polymerization 19,47 ). Amidinates are the nitrogen-analogues of carboxylates, containing two nitrogen atoms that can coordinate to metals as monodentate, bidentate, or bridging ligands (Fig.…”

Hydroboration of Aldehydes, Ketones, and Carbodiimides Promoted by Mono(imidazolin‐2‐iminato) Hafnium Complexes

“…Complexes of hafnium have been predominantly used as Lewis acid catalysts in various organic transformations, such as the polymerization of cyclic esters, and as catalysts for the homo‐ and copolymerization of α‐olefins . Recently, Hf‐MOF compounds have been used as active catalysts for the activation of small molecules .…”

New Homoleptic Rare‐Earth Metal Complexes Comprising the Unsymmetrically Substituted Amidinate Ligand [MeC(NEt)(NtBu)]–

“…[9,10] Many of them are promising homogeneous catalysts e.g. for olefin polymerization and hydroamination reactions, [11][12][13][14][15] whereas certain alkyl-substituted complexes are sufficiently volatile to be useful precursors for ALD (atomic layer deposition) and CVD (chemical vapor deposition) processes. [16][17][18][19][20][21][22][23][24] Recent contributions to this field clearly revealed that the use of unsymmetrically substituted amidinate and guanidinates ligands leads to further improved volatility of the respective transition metal and lanthanide complexes.…”