Thallium triiodide

Note that upon forming a full name — as in Na4Sn9, tetrasodium (nonastannide) and Tl(l3), thallium (triiodide) — enclosing marks may be useful to avoid ambiguity. Compare with TII3, thallium triiodide. In some circumstances, such as when the name of the electronegative species is cited alone, e.g. in the discussion of an anion, it may be useful to indicate the charge Sn9 , nonastannide(4-) (13) , triiodide(l-) 82 , disulfide(2-). This is discussed further below. Some trivial names are still... 

When polyatomic cations and/or anions are involved, enclosing marks should be used to avoid possible ambiguity. Thus Tl lj is thallium (triiodide) and Tl11113 is thallium tn-ioJide. Alternatively. thalliumU) triiodide and thalliumfllh triiudide would suffice. 

Both compounds in Examples 1 and 2 have the overall formula T1I3 and both could be named by the simple stoichiometric name thallium triiodide. However, it is possible, and usually desirable, to convey more information in the name. 

Thallium (ITT) fluoride has been prepared by the action of fluorine or bromine trifluoride on thaUium(III) oxide at 300°C. It is stable to ca 500°C but is extremely sensitive to moisture. Thallium (ITT) chloride can be obtained readily as the tetrahydrate [13453-33-3] by passing chlorine through a boiling suspension of HCl in water. It can be dehydrated with thionyl chloride. Thallium (ITT) bromide tetrahydrate [13453-29-7] is prepared similarly, whereas the iodide prepared in this manner is thaUium(I) triiodide [13453-37-7] H" F2-... 

Metal Halides. Reacts explosively or violently with the following calcium bromide iron(III) bromide or chloride iron(II) bromide or iodide cobalt(II) chloride silver fluoride all four mercury(II) halides copper(I) chloride, bromide or iodide copper(II) chloride and bromide ammonium tetrachlorocuprate zinc and cadmium chlorides, bromides, and iodides aluminum fluoride, chloride, and bromide thallium bromide tin(II) or (IV) chloride tin(IV) iodide arsenic trichloride and triiodide antimony and bismuth trichlorides, tribromides, and triiodides vanadium(V) chloride chromium(IV) chloride manganese(II) and iron(II) chlorides and nickel chloride, bromide, and iodide.17,22"25... 

All four trihalides of each element are known, with one exception. The compound T1I3, obtained by adding iodine to thallous iodide, is not thallium(III) iodide, but rather thallium(I) triiodide [Tl1 )]. This situation may be compared with the nonexistence of iodides of other oxidizing cations such as Cu2+. 

The compound in Example 1 consists of iodide, I-, and thallium, in the proportion 3 1, whereas the compound in Example 2 consists of triiodide(l—), I3, and thallium in the proportion 1 1. In the first name for the first compound, then, the multiplicative prefix tris is used to make it completely clear that three iodide ions are involved rather than one triiodide ion. The alternative names use the oxidation number III for thallium and the charge number 3+, respectively, to convey indirectly the proportions of the constituents. 

For both compounds, fully explicit names including the charge number for the thallium ion, although partly redundant, are also acceptable. Thus, thallium(3+) tris(iodide) and thallium(l+) triiodide(l—), for Examples 1 and 2 respectively, may be preferable in systematic contexts such as indexes and registries. 

The compound TII3 is isomorphous with the alkali metal triiodides and is really thallium(I) triiodide, 13.17. However, when treated with excess I , an interesting redox reaction occurs with the formation of [Tll4] (see Section 13.9). The decrease in stability of the higher oxidation state on going from the binary fluoride to iodide is a general feature of all metals that exhibit more than one oxidation state. Eor ionic compounds, this is easily explained in terms of... 

C45H76N2O12S, Tetranactin ammonium thiocyanate, 41B, 586 43B, 654 Cl, 7H7 gClgl 3NO17, 9-Propionylmaridomycin triiodide tetrachloromethane 1,2-dichloroethane solvate, 44B, 474 Cl, 7H7 yAgOi 3, Antibiotic A-130A silver salt, 43B, 656 C47H79O15TI, Carriomycin thallium salt, 45B, 552... 

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