Acetylacetonate monoanion

Picolinate (pic) Acetylacetonate (acac) Dipivaloylmethanate (dip) N-methylsalicylimine (sal) SCHEME 3.78 Chemical structures of some bidentate and monoanionic ancillary ligands. 

Complexes of dithioacetylacetone (SacSac) have been reviewed.1830 As with acetylacetone complexes, th. chemical shift of the ring methine proton has been carefully studied for metal and substituent effects in order to probe for any aromatic or anisotropic behavior in these six-membered ring complexes.1830,1831 Much of the earlier work and theories on these complexes are summarized in an electrochemical study of the dithioketone complexes of Ni, Pd and Pt.1832 The complexes undergo two successive reversible one-electron reductions in the range -0.8 to —1.8 V yielding the MSJ and MS2- core.1832,1833 The monoanion MSJ is usually... 

In the photostimulated reaction of Phi with the monoanion of acetylacetone or with the diethylmalonate anion, no substitution products were found. On the other hand, in the reaction of anthrone anion (29) with Phi a 95% yield of the substitution product (126) was formed (equation 86)169. 

But most of the chemistry of acetylacetone and related ligands concerns their behaviour as monoanions, bonding essentially in the keto-enol form (100). The types of ligands of this general... 

Multidentate oxygen ligands such as the symmetric tetrake-tone (H2L) give an asymmetric complex, [Mn3L3], which has been reported as the first asymmetric homometalhc helicate formed from a symmetric ligand. A wide variety of compounds have been studied with the jS-diketonate monoanions such as acetylacetonate (acac) and hexafluoroacetylacetonate (hfacac) that have been used as ligands in many polymeric systems. ... 

Among the most active transition metals are Mo and V, and both are effective in their highest oxidation state during reaction. Linden and Farona have foimd that Mo(V) is inactive for the epoxidation reaction and that V(IV) is converted to V (V) when contacted with a hydroperoxide [467]. The metals are added as compounds soluble in the reaction mixture, for example, Mo(CO)6, MoO2(acac), and VO(acac)2 (acac = monoanion of acetylacetone). Sheldon and Van Doom [266] have found that irrespective of the starting material, all molybdenum catalysts give rise to a common compound, a 1,2-diol complex (Fig. 1.11b). This is formed... 

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