Linear Trimeric Hafnium Clusters in Hf0.86(1)I3

Crystals

Jan Beekhuizen¹  Anja-Verena Mudring² 

[1] Department für Chemie, Universität zu Köln, Greinstraße 6, D-50939 Köln, Germany; E-Mail:;Fakultät für Chemie, Ruhr-Universität Bochum, D-44780 Bochum, Germany; E-Mail:

关键词: hafnium;    Iodide;    cluster;    crystal structure;   

DOI  :  10.3390/cryst1020040

来源: mdpi

【 摘 要 】

The reduction of hafnium tetraiodide, HfI₄, with aluminum at 600 °C or 850 °C in the presence of a NaI flux resulted in black single crystals of Hf_0.86(1)I₃. This composition corresponds well to the upper end of the non-stoichiometry range 0.89 ≤ x ≤ 1.00 previously reported for Hf_xI₃. The crystal structure (a = 1250.3(2), c = 1999.6(3) pm, R-3m, Z = 18) is made up of hexagonal closest packed layers of iodide ions. One third of the octahedral holes would be filled as in TiI₃ or ZrI₃ if it were Hf_1.00I₃. In Hf_0.86(1)I₃, one out of six octahedral holes along [001] are, however, only occupied by 16%. In contrast to TiI₃-I and ZrI₃, one striking structural feature is in the formation of linear hafnium trimers with identical Hf—Hf distances of 318.3(2) pm rather than the formation of dimers. These may be associated with Hf—Hf bonding although only 2.64 electrons are available for one Hf_5.16I₁₈ column.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.