The structural properties of the [Re(bpm)(C0),(MeQ)l2' cation were investigated in solution by proton and "C NMR. The assignments of the resonances were made by comparison to those of the uncoordinated ligands bpm (2,2'-bipyrimidine) and MeQ (N-methyl-4,4'-bipyridinium ion). Two distinct "C resonances were found for "two equivalent" sites of the bipyrimidine ligand. A crystal structure of the PF, salt revealed that the geometry of the cation was facial and the reason for the two resonances was a 9O twist of the pyrimidine rings from planarity. The crystal structure also revealed a 38' twist between the py and Me-py components of the MeQ ligand, a Re-N(bpm) bond distance of 2.17 A, and a Re-N(MeQ) bond distance of 2.21 A.

A series of bis(o-hydroxyphenyl)quinolines have been prepared, starting from 2,8-dibromoquinoline. Reaction of these new ligand precursors with group 4 tetrabenzyl complexes MBn 4 results in benzyl substitution of the azine fragment with the formation of amide complexes (M = Ti) or amine complexes with an N−H fragment coordinated to the metal (M = Zr, Hf). The third structural typeZr complexes where the aromatic system of the precursor remains intactcan be prepared through the reaction of the bis(o-hydroxyphenyl)quinolones with 4 mol of methyllithium, followed by ZrCl 4 . The new complexes result in active polymerization catalysts when activated with MAO/borate cocatalysts on silica supports, resulting in polyethylene copolymers with very high molecular weights and multimodal MWDs.

A general and efficient approach toward new zirconium and hafnium complexes based on 2-aryl-8-arylaminoquinoline ligands was developed. These precursors, when activated with MAO/borate cocatalyst and supported on silica, result in active olefin polymerization catalysts. The ethylene copolymers produced under industrially relevant conditions show very high molecular weights and unique microstructures defined by the multisite nature of the catalyst. A site-diversification mechanism is proposed to explain the presence of at least five individual sites, as deduced from 3D-TREF analysis of ethylene-butene copolymers.

The structural properties of the title complex (I) (prepared from ReCl(CO)3(2,2'‐bipyrimidine) and methyl viologen hexafluorophosphate, 84% yield) are investigated in solution by 1H and 13C NMR spectra which indicate that the C(5) carbon atoms of the pyrimidine rings are not equivalent.