Polystyrene acetylacetonate

Nickel dialkyldithiocarbamates stabili2e vulcani2ates of epichlorhydrinethylene oxide against heat aging (178). Nickel dibutyldithiocarbamate [56377-13-0] is used as an oxidation inhibitor in synthetic elastomers. Nickel chelates of substituted acetylacetonates are flame retardants for epoxy resins (179). Nickel dicycloalkyldithiophosphinates have been proposed as flame-retardant additives for polystyrene (180—182) (see Flame retardants Heat stabilizers). 

The kinetics of ligand exchange between [M(dik)4] (M = Zr or Hf dik = acac or tfacac) and the corresponding free /3-diketones have been studied by Adams and Larsen.233 [Zr(acac)4] exchanges ligands with a polystyrene resin functionalized with acetylacetonate groups to give a polymer-bound zirconium complex.234... 

Besides pyridine-containing polystyrene and pol)q5ropylene resins, polybenzimidazole has been employed as support for nickel(II) acetylacetonate [94]. The nickel-loaded polymer was shown to be an efficient catalyst for the epoxidation of (S)-(—)-limonene, a-pinene, and 1-octene using isobutyraldehyde/02 as coreac-tant/oxidant. However, significant metal leaching from the support associated with a loss of activity upon recycling was reported. It was shown that the reaction is heterogeneously catalyzed, and leached metal species did not contribute to the catal)d ic activity. 

Apart from Ti(IV), titanium complexes of other oxidation states (Ti(III) and Ti(II)), such as Ti(acac)3 (acac = acetylacetonate) and TiPh2, also show syndioselective polymerization activity and produce syndiotactic polystyrene. As for the Ti(0) complex, Ti(bipy)3 (bipy = 2,2 -bipyridine), only atactic polymer is produced (Table 14.1, entries 10-12). ... 

Titanium complexes with acetylacetonate (acac) ligands were first tested for the polymerization of styrene by Ishihara et al." and Zambelli et al When activated with MAO, Ti(acac)2Cl2 and Ti(acac)3 can produce syndiotactic polystyrene with low activities, whereas their zirconium analogues only afford atactic polystyrene. Hu and coworkers studied a series of MAO activated 1,3-diketonato titanium complexes (Figure 14.11, 53-57) and found that their activities increased in the following... 

Metal acetylacetonates are covalently bound by the reaction of crosslinked chloromethyl-ated polystyrene (DMF, 100 °C) under formation of 7 [104]. Rare earth Eu(III)-complexes of l-carboxy-8-naphthoyl bound covalently at polystyrene 8 are obtained by Friedel-Crafts acylation of the corresponding naphthalenetetracarboxylic acid anhydride with the polymer followed by reaction with Eu [105]. The luminescence properties of lanthanide ions with polycarboxylates were investigated in detail [106]. The effects of the conformation of polymer chains on electron transfer and luminescence behaviour of Co(II)-, Co(III)-ethylenediamine complexes at polycarboxylates were studied [107]. 

Other groups than amines have been used, such as crosslinked polymers and rubbers containing acetylacetonate groups with metal ions. Ito and Saegusa prepared chelating polystyrenes containing 22- and 2 membered macrocyclic-l,3-diketones (reaction 13). 

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