Group 7 elements oxoanions

Tellurium, a group 6A element, forms the oxoanions Te042- and Te032. What are the likely names of these ions To what other group 6A oxoanions are they analogous ... 

Oxoanions of even group elements have even charges (2-) and those of odd group elements have odd charges (1- or3-). 

When polycondensation of these addenda atoms is carried out in the presence of another oxoanion containing an heteroatom X, an Heteropolyanion is obtained, formulated as [XxMmOy] l , X belongs usually to the main group elements (B, Si, Ge, P, As,. ..) but can also be a metal. 

This description of the main group ions of the first three columns of the periodic table shows that with the exception of alkali metal ions all these ions are adsorbed specifically the same is true of other ions, especially the heavy metal ions, which generally are of greatest practical interest. The other main group elements form anions or oxoanions directly. In the case of equal valence, the transition metal ions resemble each other more than the main group elements do, so more generalization should be possible. 

Table 26.2 also reveals a diminished tendency on the part of these elements to form compounds of high coordination number when compared with the iron group and, apart from [Co(N03)4], a coordination number of 6 is rarely exceeded. There is also a marked reluctance to form oxoanions (p. 1118). This is presumably because their formation requires the donation of n electrons from the oxygen atoms to the metal and the metals become progressively... 

The electrochemical preparation of metal chalcogenide compounds has been demonstrated by numerous research groups and reviewed in a number of publications [ 1-3]. For the most part, the methods that have been used comprise (a) cathodic co-reduction of the metal ion and a chalcogen oxoanion in aqueous solution onto an inert substrate (b) cathodic deposition from a solvent containing metal ions and the chalcogen in elemental form (the chalcogens are not soluble in water under normal conditions, so these reactions are carried out in non-aqueous solvents) (c) anodic oxidation of the parent metal in a chalconide-containing aqueous electrolyte. 

Out of the Cd compounds with oxoanions of elements of group 16, the trimorphic CdS03 is to be mentioned, with different six-coordinate Cd in each of the three phases.289... 

This chapter consists of a description of the ions formed in aqueous solutions by the transition elements - the d-block elements - and a discussion of the variations of their redox properties across the Periodic Table from Group 3 to Group 12. There is particular emphasis on the first transition series from scandium to zinc in the fourth period, with summaries of the solution chemistry of the second (Y to Cd) and third (Lu to Hg) series. The d-block ions in solution are those restricted solely to aqua complexes of cations, e.g. [Fe(H20)f,]" +, and the various oxocalions and oxoanions formed, e.g. V02+ and MnCXj". Oxidation states that are not well characterized are omitted or referred to as such. 

Analogous oxoanions of elements in the same group of the periodic table are named similarly. Based on the names of the oxoanions of phosphorus and sulfur, name the following anions ... 

The names of monatomic anions have the ending of the element s name changed to -ide. The charge on any monatomic anion (except H ) is equal to the classical group number minus 8. The charge on each second-period oxoanion has two fewer negative charges than the... 

What can be said about the oxidation numbers of the group VIA elements in oxoanions whose names have the suffix -ate ... 

Actinyl compounds with tetrahedral oxoanions TO4 (T = S, Cr, Se, Mo) that are based upon 3D networks of comer-sharing coorination polyhedra are listed in Table 9. To proceed with their stmctural description, we shall use graph theory analysis of heteropolyhedral frameworks as developed in [221], It turns out that the most actinyl-based 3D units with comer-sharing between chemically different polyhedra can be described as based upon ID stmctural elements for which we adopt the term fundamental chain suggested by Liebau [222] for tetrahedral frameworks in silicates and related materials. However, some actinyl oxosalt stmctures are better described as consisting of polymerized 2D sheets. For convenience, the frameworks will be classified into three major groups (1) frameworks based upon fundamental chains (2) microporous chiral uranyl molybdate frameworks (3) frameworks based upon 2D sheets. 

Oxoanions are formed by elements of groups 5-8, examples being an(j KuCL... 

Further, there is little difference in energy between the various oxidation state species of sulfur, a fact that is doubtless involved in the complicated oxoacid and oxoanion chemistry of sulfur. We have already discussed some aspects of the aqueous solution chemistry of the group 16 elements ... 

There is no cation chemistry in aqueous solution for the group 16 elements. The coordination to metal ions of oxoanions such as [804] and [8203] is well established (e.g. see equation 15.112). 

Halogen Oxides, Oxoacids, and Oxoanions The Group 7A(17) elements form many oxides that are powerful oxidizing agents. Dichlorine monoxide (CI2O), chlorine dioxide (CIO2, with an unpaired electron and Cl in the unusual -t-4 oxidation state), and dichlorine heptaoxide (CLOy) are important examples. 

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