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Synthesis of the Clathrate‐II K 8.6(4) Ge 136 by Oxidation of K 4 Ge 9 in an Ionic Liquid
Author(s) -
Guloy Arnold M.,
Tang Zhongjia,
Ramlau Reiner,
Böhme Bodo,
Baitinger Michael,
Grin Yuri
Publication year - 2009
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200801073
Subject(s) - chemistry , clathrate hydrate , crystallography , metastability , ionic liquid , ionic bonding , transmission electron microscopy , crystal structure , annealing (glass) , x ray crystallography , germanium , analytical chemistry (journal) , diffraction , ion , hydrate , silicon , nanotechnology , organic chemistry , chromatography , optics , composite material , catalysis , biochemistry , materials science , physics
The new clathrate‐II K 8.6(4) Ge 136 has been synthesized by mild oxidation of K 4 Ge 9 in the ionic liquid n ‐dodecyltrimethylammonium chloride (DTAC)/AlCl 3 at 300 °C and subsequent annealing at 370 °C. Refinement of the crystal structure from X‐ray powder diffraction data revealed the composition K 8.6(4) Ge 136 [space group Fd $\bar {3}$ m , a = 15.302(1) Å], which was also confirmed by energy‐dispersive X‐ray spectrometry (EDXS), transmission electron microscopy, and scanning electron microscopy on the bulk material. K atoms preferably occupy the larger Ge 28 cages rather than the Ge 20 cages in the clathrate‐II structure. K 8.6(4) Ge 136 is metastable and was found to decompose exothermically at 471 °C. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)