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Semiclathrates of the Ge–P–Te System: Synthesis and Crystal Structures
Author(s) -
Kirsanova Maria A.,
Reshetova Liudmila N.,
Olenev Andrei V.,
Abakumov Artem M.,
Shevelkov Andrei V.
Publication year - 2011
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201003553
Subject(s) - tellurium , crystallography , superstructure , covalent bond , clathrate hydrate , crystal structure , group (periodic table) , chemistry , materials science , inorganic chemistry , physics , hydrate , thermodynamics , organic chemistry
Novel compounds [Ge 46− x P x ]Te y (13.9≤ x ≤15.6, 5.92≤ y ≤7.75) with clathrate‐like structures have been prepared and structurally characterized. They crystallize in the space group Fm $\bar 3$ with the unit cell parameter changing from 20.544(2) to 20.698(2) Å ( Z =8) on going from x =13.9 to x =15.6. Their crystal structure is composed of a covalently bonded GeP framework that hosts tellurium atoms in the guest positions and can be viewed as a peculiar variant of the type I clathrate superstructure. In contrast to the conventional type I clathrates, [Ge 46− x P x ]Te y contain tricoordinated (3 b ) atoms and no vacancies in the framework positions. As a consequence of the transformation of the framework, the majority of the guest tellurium atoms form a single covalent bond with the host framework and thus the title compounds are the first representative of semiclathrates with covalent bonding. A comparison is made with silicon clathrates and the evolution of the crystal structure upon changing the tellurium content is discussed.