Hafnium acetylacetonate

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.[2]

Hafnium acetylacetonate[1]

Names
IUPAC name hafnium(4+); (Z)-4-oxopent-2-en-2-olate
Other names tetrakis(acetylacetonato)hafnium, hafnium tetrakis(acetylacetonate)
Identifiers
CAS Number	17475-67-1
3D model (JSmol)	Interactive image
PubChem CID	21953595
InChI InChI=1S/4C5H8O2.Hf/c4*1-4(6)3-5(2)7;/h4*3,6H,1-2H3;/q;;;;+4/p-4/b4*4-3-; Key: MCFIMQJAFAOJPD-MTOQALJVSA-J
SMILES [Hf+4].O=C(C)\C=C(/[O-])C.[O-]\C(C)=C/C(C)=O.[O-]\C(C)=C/C(C)=O.[O-]\C(C)=C/C(C)=O
Properties
Chemical formula	C20H28HfO8
Molar mass	574.93 g·mol^−1
Appearance	White to off-white powder
Density	1.42 g/cm^3
Melting point	193 °C (379 °F; 466 K) (decomposes)
Solubility in benzene	good
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Uses

Along with titanium tetrabutoxide (TBT), hafnium acetylacetonate serves as a catalyst for the production of poly(butylene terephthalate).[3]

References

1. "Hafnium Acetylacetonate". American Elements. Retrieved 2015-04-05.
2. Zherikova, K. V.; Morozova, N. B.; Kuratieva, N. V.; Baidina, I. A.; Igumenov, I. K. (November 2005). "Synthesis and structural investigation of hafnium(IV) complexes with acetylacetone and trifluoroacetylacetone". Journal of Structural Chemistry. 46 (6): 1039–1046. doi:10.1007/s10947-006-0239-2.
3. Banach, T.E; Berti, C; Colonna, M; Fiorini, M; Marianucci, E; Messori, M; Pilati, F; Toselli, M (August 2001). "New catalysts for poly(butylene terephthalate) synthesis". Polymer. 42 (18): 7511–7516. doi:10.1016/S0032-3861(01)00219-1.