Nickel(II) chloride (or just nickel chloride) is the chemical compound NiCl2. The anhydrous salt is yellow, but the more familiar hydrate NiCl2·6H2O is green. Nickel(II) chloride, in various forms, is the most important source of nickel for chemical synthesis. The nickel chlorides are deliquescent, absorbing moisture from the air to form a solution. Nickel salts have been shown to be carcinogenic to the lungs and nasal passages in cases of long-term inhalation exposure.
Nickel(II) bis(acetylacetonate) is a coordination complex with the formula [Ni(acac)2]3, where acac is the anion C5H7O2− derived from deprotonation of acetylacetone. It is a dark green paramagnetic solid that is soluble in organic solvents such as toluene. It reacts with water to give the blue-green diaquo complex Ni(acac)2(H2O)2.
Metal acetylacetonates are coordination complexes derived from the acetylacetonate anion (CH
3COCHCOCH−
3) and metal ions, usually transition metals. The bidentate ligand acetylacetonate is often abbreviated acac. Typically both oxygen atoms bind to the metal to form a six-membered chelate ring. The simplest complexes have the formula M(acac)3 and M(acac)2. Mixed-ligand complexes, e.g. VO(acac)2, are also numerous. Variations of acetylacetonate have also been developed with myriad substituents in place of methyl (RCOCHCOR′−). Many such complexes are soluble in organic solvents, in contrast to the related metal halides. Because of these properties, acac complexes are sometimes used as catalyst precursors and reagents. Applications include their use as NMR "shift reagents" and as catalysts for organic synthesis, and precursors to industrial hydroformylation catalysts. C
5H
7O−
2 in some cases also binds to metals through the central carbon atom; this bonding mode is more common for the third-row transition metals such as platinum(II) and iridium(III).
Barium acetylacetonate is a compound with formula Ba(C5H7O2)2. It is the Ba2+ complex of the anion acetylacetonate. The compound is typically encountered as an ill-defined hydrate, which would accord with the high coordination number characteristic of barium.
Dysprosium acetylacetonate is a chemical compound of dysprosium with formula Dy(C5H7O2)3(H2O)n.
Europium acetylacetonate is a coordination complex with formula Eu(C5H7O2)3. Although this anhydrous acetylacetonate complex is widel discussed, some sources suggest that it is really the dihydrate Eu(C5H7O2)3(H2O)2.
Gadolinium acetylacetonate is a coordination compound with the formula Gd(C5H7O2)3. This anhydrous acetylacetonate complex is widely discussed but unlikely to exist per se. The 8-coordinated dihydrate Gd(C5H7O2)3(H2O)2 is a more plausible formula based on the behavior of other lathanide complexes. It has also been characterized twice by X-ray crystallography.
Gallium acetylacetonate, also referred to as Ga(acac)3, is a coordination complex with formula Ga(C5H7O2)3. This gallium complex with three acetylacetonate ligands is used in research. The molecule has D3 symmetry, being isomorphous with other octahedral tris(acetylacetonate)s.
Hafnium acetylacetonate, also known as Hf(acac)4, is a coordination compound with formula Hf(C5H7O2)4. This white solid is the main hafnium complex of acetylacetonate. The complex has a square antiprismatic geometry with eight nearly equivalent Hf-O bonds. The molecular symmetry is D2, i.e., the complex is chiral. It is prepared from hafnium tetrachloride and acetylacetone, and base. Zr(acac)4 is very similar in structure and properties.
Rhodium acetylacetonate is the coordination complex with the formula Rh(C5H7O2)3, which is sometimes known as Rh(acac)3. The molecule has D3-symmetry. It is a yellow-orange solid that is soluble in organic solvents.
Tris(acetylacetonato)cobalt(III) is the coordination complex with the formula Co(C5H7O2)3. Often abbreviated Co(acac)3, it is a green, diamagnetic solid that is soluble in organic solvents, but not in water. Owing to its solubility in organic solvents, tris(acetylacetonato)cobalt(III) is used to produce homogeneous catalysts by reduction.
Yttrium oxalate is an inorganic compound, a salt of yttrium and oxalic acid with the chemical formula Y2(C2O4)3. The compound does not dissolve in water and forms crystalline hydrates—colorless crystals.
Neodymium(III) acetylacetonate is a coordination compound with the chemical formula Nd(O2C5H7)3. Although many sources discuss this anhydrous acetylacetonate complex, it is the dihydrate Nd(O2C5H7)3(H2O)2 that has been characterized by X-ray crystallography. It commonly occurs as a white powder. Upon heating under vacuum, other dihydrated lanthanide trisacetylacetonates convert to oxo-clusters M4O(C5H7O2)10. This result suggests that Nd(O2C5H7)3 may not exist.
Holmium acetylacetonate is a coordination complex, with the chemical formula of Ho(C5H7O2)3 or Ho(acac)3. It can be obtained via the reaction between metallic holmium or holmium(III) hydride with acetylacetone, or via the reaction between holmium(III) chloride and ammonium acetylacetonate. Its anhydrous form is stable in a dry atmosphere but forms a hydrate in humid air.
Erbium compounds are compounds containing the element erbium (Er). These compounds are usually dominated by erbium in the +3 oxidation state, although the +2, +1 and 0 oxidation states have also been reported.
Yttrium acetylacetonate is a coordination compound with the chemical formula Y(C5H7O2)3(H2O)x, or Y(acac)3(H2O)x for short. The value of x can vary from 1 to 3.
Praseodymium acetylacetonate is a coordination complex with the formula Pr(C3H7O2)3. This purported anhydrous acetylacetonate complex is widely discussed but only the dihydrate Pr(C3H7O2)3(H2O)2 has been characterized by X-ray crystallography.
Erbium acetylacetonate is a coordination compound, with the chemical formula of Er(C5H7O2)3, or Er(acac)3 for short.
Lutetium acetylacetonate is a coordination compound with the chemical formula Lu(C5H7O2)3, or Lu(acac)3 for short. It is isomorphic to ytterbium acetylacetonate. It can be prepared by the reaction of trialkoxylutetium and acetylacetone.
