Thallium complexes 1,3-diketones

Thallium complexes amidines, 205 phthalocyanines, 863 porphyrins, 821 triazines, 205 Thallium(I) complexes hexafluoroacetylacetone, 372 Thallium III) complexes carboxylic acids reactions, 443 1,3-diketones synthesis, 377... 

Diarylacetylenes are converted in 55-90% yields into a-diketones by refluxing for 2-7 h with thallium trinitrate in glyme solutions containing perchloric acid [413. Other oxidants capable of achieving the same oxidation are ozone [84], selenium dioxide [509], zinc dichromate [660], molybdenum peroxo complex with HMPA [534], potassium permanganate in buffered solutions [848, 856, 864,1117], zinc permanganate [898], osmium tetroxide with potassium chlorate [717], ruthenium tetroxide and sodium hypochlorite or periodate [938], dimethyl sulfoxide and iV-bromosuccin-imide [997], and iodosobenzene in the presence of a ruthenium catalyst [787] (equation 143). 

Although T1(III) adducts of /3-diketones are not available, the homoleptic tropolonato derivative has been synthesized. The tris(tropolonato)thallium(III) can bind to trioctylphosphine oxide forming seven-coordinate complexes. The indium(III) analogue behaves similarly. 

The most stable oxo-complexes are chelate compounds. Gallium and indium form tris- -diketone complexes, soluble in alcohol and benzene, and structurally similar to those of aluminium (Fig. 155). Gallium and thallium form trioxalato compounds like the oxalato-aluminates MJ[Ga ( 304)3]HgO. All the metals form tris-complexes with oxine (Fig. 156). 

Bromo(bispentafiuorophenyl)thallium reacts with the sodium or thallium(i) salts of the j8-diketones, (MeCO)gCH2, CFa-CO-CHa-COMe, (CF, CO)3-CH2,PhCOCHj-COMe,and (PhCO)sCH, to form four-co-ordinate dionato complexes, e.g. (C,F5)sTl[(MeCO),CH], and with the sodium salt of 8-hydroxyquinoline to form a dinuclear complex with bridging ligands. Reaction of these with triphenylphosphine oxide and triphenylarsine oxide, and with 2,2 -bipyridyl and phenanthrene, yields a number of five- and six-co-ordinate complexes. ... 

Several diketonate thallium(I) complexes with a different number of alkoxy groups on the aromatic ring have been synthesized [79]. The mesogenic behavior of the thalli-um(I) and of the copper(II) derivatives are qualitatively similar. The authors propose a dimer structure. 

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