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)
“The verbal poetical texture of Shakespeare is the greatest the world has known, and is immensely superior to the structure of his plays as plays. With Shakespeare it is the metaphor that is the thing, not the play.”
—Vladimir Nabokov (1899–1977)
“Man is more disposed to domination than freedom; and a structure of dominion not only gladdens the eye of the master who rears and protects it, but even its servants are uplifted by the thought that they are members of a whole, which rises high above the life and strength of single generations.”
—Karl Wilhelm Von Humboldt (1767–1835)