Structure
Paratellurite, α-TeO2, converts at high pressure into the β-, tellurite form. Both the α-, (paratellurite) and β- (tellurite forms) contain four coordinate Te with the oxygen atoms at four of the corners of a trigonal bipyramid. In paratellurite all vertices are shared to give a rutile-like structure, where the O-Te-O bond angle are 140°. α-TeO2 In tellurite pairs of trigonal pyramidal, TeO4 units, sharing an edge, share vertices to then form a layer. The shortest Te-Te distance in tellurite is 317 pm, compared to 374 pm in paratellurite. Similar Te2O6 units are found in the mineral denningite.
TeO2 melts at 732.6 °C, forming a red liquid.
Read more about this topic: Tellurium Dioxide
Famous quotes containing the word structure:
“Science is intimately integrated with the whole social structure and cultural tradition. They mutually support one other—only in certain types of society can science flourish, and conversely without a continuous and healthy development and application of science such a society cannot function properly.”
—Talcott Parsons (1902–1979)
“A special feature of the structure of our book is the monstrous but perfectly organic part that eavesdropping plays in it.”
—Vladimir Nabokov (1899–1977)
“The syntactic component of a grammar must specify, for each sentence, a deep structure that determines its semantic interpretation and a surface structure that determines its phonetic interpretation.”
—Noam Chomsky (b. 1928)