니켈 아세틸아세톤산

Nickel(II) acetylacetonate Ni(CH3COCHCOCH3)2, is obtained as emerald green crystals by dehydration of the dihydrate at 50°C in vacuum; it has an unusual trimeric structure in the solid state. The dihydrate Ni(CH3COCH3)2.2H2O is prepared by the addition of acetylacetone to solutions of nickel(II) salts in the presence of a weak base such as sodium acetate. Nickel(II) acetylacetonate is soluble in organic solvents and finds use in the synthesis of organometallic compounds such as nickelocene and bis(cyclooctadiene) nickel. It is also industrially important as a catalyst component in the oligomerization of alkenes and in the conversion of acetylene to cyclooctatetraene.

용도Nickel(II) acetylacetonate is usefully soluble in organic solvents and is therefore used in the Grignard synthesis of nickelocene from cyclopentadienyl magnesium halides. More ionic nickel(II) salts such as the thiocyanate can be reacted with potassium cyclopentadienide in liquid ammonia.

Nickel(II) acetylacetonate is isolated as the dihydrate Ni(acac)2·2H2O from aqueous solutions of nickel(II) salts in the presence of acetylacetone and a weak base such as sodium acetate; it is readily dehydrated to the green anhydrous compound at 50° in vacuo. From ammoniacal solutions of nickel(II) salts the diammoniate Ni(acac)2·2NH3 precipitates; this also readily evolves the two extra ligands to give the green acetylacetonate.