Abdolali Alemi,^a Esmaiel Soleimani,*^a Zoya A. Starikova^b
a : Inorganic Synthesis Laboratory, Faculty of Chemistry, Tabriz University, Tabriz, IRAN   Phone : 0098 41 355998, Fax : 0098 41 340191, soleimani@ark.tabrizu.ac.ir
^b: X-ray Structural Center, General and Technical Chemistry Division, Academy of Science of Russia, star@xrpent.ineos.ac.ru
 

ABSTRACT

The reaction of iodine trichloride with tellurium in a sealed evacuated glass ampoule at 250 oC yields yellow-green, moisture sensitive crystals of TeCl4. The crystal structure of TeCl4  has been determined in low temperature at 100 K from three-dimensional X-ray data collection. The compound crystallizes in space group C2/c of monoclinic system with unit cell dimensions a = 16.846(3)A, b = 10.347(2)A, c = 15.051(3) A, ? = 116.87(3) o, Z = 8, V = 2340.2(8) A3  , roc = 3.059 g/cm3 , final R indices [ I>2sigma (I) ] R = 0.0507, wR = 0.1304 , and R indices (all data) R = 0.0564, wR = 0.1341.
The structure consists of tetramers, Te4Cl16, which have a cubane-like structure. The Te atoms occupy the half of the corners with Td  symmetry. Each Te atom has been attached to three terminal Cl atoms with an average distance of 2.325A. The coordination of the Te atom is completed to a distorted octahedron by three bridging chlorine atoms with much longer Te-Cl bond lengths (average 2.915A). In the polar limiting case the structure may be described, in a rough approximation, as an arrangement of TeCl3+ ions with nearly C3v symmetry and of Cl- ions. The structure data suggest possible concentration of the nonbonding Te electrons toward the center of the cubane skeleton.