Zirconium chelate structure

ZrCU RC(0)NHC(0)NH2 ] (R = Me or Ph).132 IR studies indicate that urea coordinates to zirconium through the carbonyl oxygen atom.131 The acylureas coordinate through both oxygen atoms, giving a chelate structure.132... 

Chem. Descrip. Zirconium chelate in 2,4-pentanedione Uses Catalyst for two-component urethane coatings (automotive topcoats, high performance maintenance coatings, aerospace coatings, coatings for structural plastics)... 

Mercury, like zinc, appears in some chain-like structures, but apparently only in combination with other metals such as As, Sb, Nb, and Ta. Some of these have the characteristics of metallic conductors.15 Rather high molecular weights have been obtained in the preparation of 6-coordinate cobalt (III) chelate polymers with acetylacetonato and leucinato ligands, 7-coordinate dioxouranium-(VI) dicarboxylate polymers, and 8-coordinate zirconium (IV) polymers with Schiff-base ligands.77... 

You may not be able to fix it. Zirconium columns have a different chemical structure than silica. They are more pH resistant and can be used at elevated temperatures, but they run differently than a silica Ci8. First, find out if it has a chemically bonded tetraphosphonic acid chelator. If not, you may have to add a chelator to the mobile phase. If you are not getting sharp peaks, make sure you have made new inlet tubing specifically for this column. Old tubing can ruin the performance of a new column. Run a standard mix on both columns and see how they differ. This column can give you the ability to separate mixture that you can t separate on a reverse-phase silica column. 

A variety of new ligand designs and ligand combinations were used in attempts to mimic some properties of the ubiquitous bent metallocene environment at the early metal centers consequently, some of these systems were used in the further development of butadiene zirconium chemistry. The pyridine based chelate zirconium dichloride complex 43 cleanly formed the butadiene complex 44 upon treatment with butadiene-magnesium. Its structure shows that the C4H6 is arranged perpendicular to the chelate ligand plane. Complex 44 inserts one equivalent of an alkene or alkyne to form the metallacyclic 7i-allyl system 4545 (Scheme 13). 

There are few exceptions in zirconium/phosphine compounds to the basic [ZrCl3L2]2 structural motif. The presence of the chelating phosphine ligand dppe [bis(diphenylphosphino)ethane] in a toluene solution of ZrCl4 results in the formation of the green compound,... 

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