Zirconium complexes 2,2 -bipyridyl

Mn(II) > Mg(II).270 It should be underlined that titanium and zirconium alkoxides are efficient catalysts for both stages of reaction. Lanthanide compounds such as 2,2/-bipyridyl, acetylacetonate, and o-formyl phenolate complexes of Eu(III), La(III), Sm(III), Er(III), and Tb(III) appear to be even more efficient than titanium alkoxides, Ca or Mn acetates, Sb203, and their mixtures.273 Moreover, PET produced with lanthanides has been reported to exhibit better thermal and hydrolytic stability as compared to PET synthesized with the conventional Ca acetate -Sb203 catalytic system.273... 

The properties of a- or y- zirconium hydrogen phosphate, a synthetic inorganic ion-exchanger material with layered structure, as "heterogenizing" support for carbonylation reactions are still to be studied. Our first studies in this field showed that the Pd(II)-2,2 -bipyridyl complex intercalated in these materials catalyzes the oxidative carbonylation of aniline even though its activity falls with time, because the support slowly loses palladium and deactivates during the catalysis process [2]. 

Homoleptic anionic zirconium and hafnium phosphine complexes have recently been prepared using bisphosphinine ligands, which are phosphine analogs of the ubiquitous bipyridyl ligand. Structure determinations of the Li3(solv)Cl salts were performed (solv = DME for M = Zr and THF for M = Hf) show the overall geometry around the metal center to be trigonal prismatic. Disruption of the aromaticity is... 

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