Interhalogens table

Typical examples of linear (or nearly linear) triatomic polyhalides are in Table 17.15 the structures are characterized by considerable variability of interatomic distances and these distances are individually always substantially greater than for the corresponding diatomic interhalogen (p. 825). Note also that for... 

At(0) reacts with halogens X2 to produce interhalogen species AtX, which can be extracted into CCI4, whereas halide ions X yield polyhalide ions AtX2 which are not extracted by CCLt but can be extracted into Pr O. The equilibrium formation constants of the various trihalide ions are intercompared in Table 17.28. 

The halogens form compounds among themselves. These interhalogens have the formulas XX, XX 5, XX 5, and XX 7, where X is the heavier (and larger) of the two halogens. Only some of the possible combinations have been synthesized (Table 15.5). They are all prepared by direct reaction of the two halogens, the... 

TABLE 15.5 Interhalogcn Known Interhalogens Normal form... 

A third factor comes into play in bromine chemistry, which is that atmospheric solutions containing bromide and chloride are most typically formed from seawater. Wave action generates small airborne droplets of seawater, which thus initially contain the elements in the ratios found in seawater. The molar ratio of Br- to Cl- is 1 650. However, despite the relatively small amounts of bromide relative to chloride, it plays a disproportionate role because of its reactivity and because its chemistry is closely intertwined with chloride ion chemistry. Table 8.16, for example, shows some of the interhalogen reactions of bromide and chloride. It can be seen that the chemistry preferentially generates Br2 rather than Cl2. 

Table 11.1 Major Interhalogen Compounds Compound Name and Formula Physical Properties... 

Fluorine is a sufficiently strong oxidant to oxidize chlorine, bromine, and iodine, whereas chlorine can oxidize bromine and iodine. The compounds thus formed are called interhalogen compounds. The major interhalogen compounds are listed in Table 11.1. 

The halogens react with each other to form binary interhalogen compounds XY, XY3, XY5 and XY7, where X is the heavier halogen. A few ternary compounds are also known, e.g., IFCI2 and IF2CI. All interhalogen compounds contain an even number of halogen atoms. Table 17.2.1 lists the physical properties of some XYm compounds. 

Table 17.2.1. Physical properties of some interhalogen compounds...

These ions have the general formulas XY+ and XY , where n can be 2, 4, 5, 6, and 8, and the central halogen X is usually heavier than Y. Table 17.2.2 lists many of the known interhalogen ions. 

The interhalogens, particularly the halogen fluorides, are chemically very reactive materials and hydrolyze easily. The handling and manipulation of these, their derivatives, and cationic or anionic species have to be performed using the safety precautions customary in fluorine chemistry (exclusion of moisture and air, and in vacuum lines constracted from materials that are resistant to fluorine). The properties of the interhalogens are intermediate between those of their parent halogens, and some physical properties are summarized in Table 4. 

Several trends are noticeable from the data in the table. The bond strengths of the interhalogens are clearly related to the dift erence in electronegativity between tbe component halogen atoms, as expected on the basis of Pauling s ideas on ionic character (Chapter 5). Furthermore, the tendency to form the higher fluorides and chlorides depends upon the initial eiectronegativiiy of the central atom.- Only iodine forms a heptafluoride or a trichloride. Not shown in Table 17.2 (except indirectly by computation from the values) is the instability of certain lower oxidation states to disproportionation ... 

Bromine vapour diluted with nitrogen reacts with fluorine to give mainly BrFg, unless an excess of Fg is present, when BrFg is the chief product. There are eleven interhalogen compounds of the four types shown in Table 89 ... 

Table 15.5 in the text provides a compilation of the known interhalogens. 

---