Tellurium, polyatomic cations

Thus, sulfur is the element richest in allotropes,1 while tellurium holds the record for the number of positively charged polyatomic cations. Moreover, tellurium (and to a lesser extent Se) is at the border between a nonmetal and a metal thus, solid grey Se and Te are semiconductors and especially... 

Important thermodynamic properties that relate to the structure and stability of the chalcogen ailotropes and their polyatomic cations are the formation enthalpies listed in Table 2. Only reliable experimentally or quantum chemically established numbers have been included. From Table 2 it is evident that tellurium is the least investigated with respect to the entries thus, there is clearly space for more thorough experimental or quantum chemical work in this direction. Therefore, we have assessed the missing Te data from the IP determination in ref. 12 (PE spectroscopy) and ref. 13 (quantum chemical calculations) and have put them in the table in parentheses, although it is clear that the associated error bars are relatively high. The data in ref. 14 were not considered. 

Polyheteroatom Cations. So far, only studies on homopolyatomic cations of oxygen, sulfur, selenium, and tellurium have been discussed. Most of them were of the type X,21. There is a new class of polyatomic cations that comprise two or more heteroatoms. 

Like their sulfur congener, selenium and tellurium can form polyatomic cations and anions in many compounds. 

Table 12-3 Polyatomic Cations of Sulfur, Selenium, and Tellurium...

The preparation and properties of homopolyatomic cations of the Group VI elements have been reviewed recently.1 The general method described below, involving the oxidation of elemental sulfur, selenium, and tellurium with either antimony pentafluoride or arsenic pentafluoride in liquid sulfur dioxide, is convenient for the preparation of compounds containing these polyatomic cations. The procedure is basically that briefly described previously2 for the preparation of Se8(Sb2F j i )2. 

Polyatomic Chalcogen Polymers and Polymeric Tellurium Cations... 

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