Bidentate acetate ligands

The molecular structures of several [TpBut]ZnX derivatives have been determined by x-ray diffraction. For example, x-ray diffraction studies confirm that the acetate ligand in [TpBut]Zn(r)1-02CMe) is bound to zinc in a unidentate mode, similar to that proposed for [TpBut]Mg(7j1-02CMe), but in contrast to the bidentate coordination proposed for the copper analogue [TpBut]Cu(T)2-02CMe) (86,87). Such a change in coordination mode for copper and zinc derivatives is to be anticipated on the basis of structural studies on the nitrate derivatives [TpBut]M(N03) (M = Co, Ni, Cu, Zn), as described in Section V,B,2,e. The thioacetate [TpPh]-Zn V-SC(0)Me (81), and cyanoacetate [Tp lZnlr -C CCH N) (88) derivatives also exhibit unidentate coordination. 

Triacontanuclear Octahedral Clusters Stabilized by Bidentate Acetate Ligand... 

In this instance, the resulting species possess both alkoxide and acetate ligands. Because the acetate species may be (and typically are) bidentate in nature,77 as well as sterically larger than short chain alkoxy groups, they are less susceptible to attack by water, and the hydrolysis and condensation reactions are slowed. Because of the reduced sensitivity toward hydrolysis, the nature of the precursor species resulting from these processes is desirable for film formation (to be discussed in Sections 2.5 and 2.6). 

RuH(COOMe)(PPh3)3] 0.089 highly distorted octahedral Ru coordination. Acetate ligand is bidentate, weakly held (Ru—O ca. 2.2 A) b... 

In another study, these workers found that cis complexes of palladium acetate with bidentate ligands such as o-phenanthroline will catalyze the exchange at higher temperatures (190). As trans complexes were inactive, it is likely that two adjacent cis coordination positions are required for catalysis. These new catalysts are extremely interesting and deserve further mechanistic study. 

The most commonly used compound for C-based solid-state temperature measurements is samarium acetate tetrahydrate. The Sm + is nine-coordinated by the oxygen atoms of three bidentate acetate ligands, two water molecules, and a bridging oxygen from an acetate ligand of an adjacent... 

Upon hydroysis, alkoxy groups are removed first, whereas bidentate acetate ligands remain bonded to titanium. They prevent further condensation and increase the gelation time. The functionality of the new molecular precursor de-... 

Added acetate ion promoted the Hirao coupling of PH(0)(0R)2 with aryl bromides and iodides. Formation of a bidentate acetate ligand was suggested to result in PPh3 dissociation, yielding a more reactive Pd electrophile for coordination (followed by deprotonation) of the H-phosphonate. P-C reductive elimination would then yield the product (Scheme 59) [99, 100]. 

Based on many experimental details, it is strongly believed that olefins form a coordination complex with mercuric salts in solution, which can decompose to release olefins again. As only 10 outer electrons are available for Hg +, the complexes from olefin and mercuric halides that do not have a stable 18-electron configuration require additional ligands of hydroxide in aqueous solution for comparison, the complexes from olefin and mercuric acetate are stable because acetate is bidental. Olefin is activated as of coordination, so that the formation of an addition product is quite possible. A tentative mechanism is outlined here to show the dynamic equilibrium between the coordination complex and the addition product. 

McCleverty, Ward and co-workers have characterized a [Cu2L2(OAc)2] " helicate based on square-pyramidal Cu. " One bidentate pyridyl/pyrazolyl chelate from each ligand and one monodentate terminal acetate ligand complete the copper coordination sphere. 

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