Diketonato ligands

Komiya, S., and Kochi, J.K. (1977) Reversible linkage isomerisms of p-diketonato ligands. Oxygen-bonded and carbon-bonded stmctures in gold(III) acetylacetonate complexes induced by phosphines. Journal of the American Chemical Society, 99, 3695. 

In related work, an unusual ytterbium(IIl) complex, [(i7-C5Me5)2-Yb]2[Fe3(CO)7(ja-CO)4], was shown by Tilley and Andersen to contain four isocarbonyl ligands (30). The iron portion of this complex acts formally as a l,3,5-trimetalla-/3-diketonato ligand coordinated to the two Yb(III) ions. 

Metalla-j3-diketones or metalla-/3-diketonate anions react with trigonal boron compounds, BX2Y, in which X = Y = halogen or X = Cl and Y = Ph, to afford neutral (metalla-/3-diketonato)B(X) (Y) complexes. Complexes of this type are known with mangana-, rhena-, and ferra-/3-diketonato ligands. The earlier chemistry of these complexes has also been previously reviewed (J). 

Solvent-solvent and solvent-solute interactions were examined by measuring the Raman spectrum of CO2 in neat "C02 and in solutions of -diketones (acacH, tfacH and hfacH) or the complex [U02(hfac)2DMS0]". It was found that the Raman bands of "C02 containing -diketones are shifted to lower wave numbers compared to neat CO2 and no shift to lower wave numbers was observed for the uranyl complex solution. Acid-base interactions between the carbonyl oxygen atoms of diketonato ligand and... 

The luminescent cyclometalated Pt(II) complexes 5, with absorption maxima around 520 nm, exhibit similarly structured emission bands, independent of the nature of the /3-diketonato ligand. A representative complex of this type (R = H, R = Me) in a frozen EPA (ether-isopentane-alcohol) glass at 77 K has two sets of vibrationally structured bands (460-560 nm, 570-800 nm), due to the presence of two emitting isomeric species. 

Silicon-containing S-diketonate anions (14) provides an attractive, novel approach to modification of the thermal stability and volatility of Cu(II) MOCVD precursors based on / -diketonato ligands. Multinuclear NMR studies suggest that the sUa-/ -diketons exist as the enolic tautomer with a C=C—Si structure. 

One of the few examples in which an aryl ligand acts as the deprotonating agent to form an enolato ligand is the reaction of 121 with ethyl acetate to afford a rare example of a complex, 122, with a bridging instead of chelating diketonato ligand. In addition, a condensation reaction takes place". ... 

In some cases, complexes with a monocoordinated /3-diketonato ligand are obtained by substitution of other monodentate terminal ligands. Thus, PhCH(CHO)2 reacts with [SnPh3(OEt)] to afford the polymer [SnPh3 OCH=C(Ph)CHO ] . 

Dibenzoylacetone (132) reacts with [Pt(C03)L2] (L = PPhs, AsPh3) to give complex 133 containing a dianionic /3,/3 -bis(diketonato) ligand". ... 

The abbreviations listed below are used in the chapter. Unless otherwise stated, the diketonato ligands are assumed to be 0,0 -dicoordinated. 

There are many complexes containing a C,0,C-/3-diketonato ligand. The best known example is 35, which can be prepared by reacting PtMesX with M(acac) (M/X = H/ 804", Na/V2S04" , Replacement of a ligand in a /3-diketonato complex by a... 

Reaction of 0,0-diketonato complexes with strong nucleophiles can replace one coordinated oxygen to give a complex with a /c -O-diketonato ligand. Thus, addition of P(c-Hex)3 to an acetone solution of tropolonato (tropo) complex 46 gives 47. Similarly, Ag(tropo) reacts with P(Bu-n)3 to give [Ag(0-tropo)P(Bu-n)3]. ... 

Pt(F3acac)2] reacts with two equivalents of neutral ligands (L = PArs, AsPhs, py) to give 101 and [Pt(acac)2] reacts with two equivalents of PPhs in hot MeOH to afford 102 containing, respectively, a di- or trianionic / -diketonato ligand. The latter also contains a noncoordinated acac counterion (Section Vin.A.)... 

A. Formation of Complexes with Noncoordinated / -Diketonato Ligands... 

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