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Title: Crystal structure of tetrakis(1,1,1,5,5,5-hexafluoroacetylacetonato)hafnium(IV)
The crystal structure of the title compound, [Hf(C 5 HF 6 O 2 ) 4 ], has been determined. The asymmetric unit contains two Hf(hfac) 4 molecules (hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate); both are located on general positions and have identical structures apart from the disorder involving three CF 3 groups in one of the two molecules. The molecules of Hf(hfac) 4 are arranged in layers that are parallel to the ab plane, and the coordination geometry of each hafnium(IV) center is a distorted square antiprism. An interesting aspect of the structure is that the hfac ligands are arranged so that the Hf(hfac) 4 molecules have idealized 2 point symmetry, in which two of the hfac groups bridge between the two squares. Although all other M (β-diketonate) 4 compounds of Hf (and Zr) also have square-antiprismatic geometries; in almost all of them the ligands are arranged so that the molecules have 222 point symmetry (in which none of the hfac ligands bridges between the two squares). The factors that favor one structure over another are not clear.  more » « less
Award ID(s):
1665191
PAR ID:
10097543
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Acta Crystallographica Section E Crystallographic Communications
Volume:
74
Issue:
8
ISSN:
2056-9890
Page Range / eLocation ID:
1182 to 1185
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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