Fluorine, chlorine, bromine and iodine

In Sections 11.5, 12.5, 13.6, 14.8, 15.7 and 16.7 we have discussed the halides of the group 1, 2, 13, 14, 15 and 16 elements respectively. Fluorides of the noble gases are discussed in Sections 18.4 and 18.5, and of the d- and /-block metals in Chapters 21, 22 and 27. In this chapter, we discuss the halogens themselves, their oxides and oxoacids, interhalogen compounds and polyhalide ions. 

The structures reported in this Group are divided equally into oxo- or thio-ionic species and interhalogen ions. 

Two crystal structures containing perchloric acid have been described, the sesterhydrate and tiihydrate, both studied at low temperatures. This has allowed the determination of ordered ClOi ions. The Cl-O distances in the two crystallographically independent anions in the former and the sin e ion in the latter range from 1.414 to 1.456 A and the angles from 107.9 to 111.1°. The ions are completely deprotonated, the protons having been used to form HgO+ or H7O8+ ions. 

The anion in CsIOFg has the expected square-pyramidal geometry, with 1=0 at 1.72 A and I-F distances in the range 1.95-1.98 A. The iodine atom lies 0.05 A below the Fg plane, away from the oxygen atom. The I SC(NHj)a + ion in bis(thiourea)iodine iodide has a centrosymraetric structure, with a linear SIS unit I-S is 2.629 A and S-C is 1.724 A, which is not lengthened by the formation of the S-I bond. The I-S-C angle is 106.3°. 

The I-S distance in the 2 1 complex of IBr with 1,4-dithian is 2.687 A, and I-Br is 2.646 A. The IBr group adopts an equatorial position with respect to the S2O4 ring, which is in the chair conformation. 

The dibromine cation, Brg+, studied in the form of its SbaF, salt, has a Br-Br distance of 2.15 A compared with the 2.27 A in the Brg molecule. The reduction is explained in terms of the loss of the electron from a iTgAp antibonding orbital. 

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The mix of inductive and resonance effects varies from one halogen to another but the net result is that fluorine chlorine bromine and iodine are weakly deactivating ortho para directing substituents... 

The most important of the halogenated derivatives of acetic acid is chloroacetic acid. Fluorine, chlorine, bromine, and iodine derivatives are all known, as are mixed halogenated acids. For a discussion of the fluorine derivatives see Fluorine compounds, organic. 

Synthetic procedures are available for the preparation of fluoro, chloro, bromo and iodo compounds from the corresponding lithio derivatives. Perchloryl fluoride (FCIO3), N-chlorosuccinimide, bromine and iodine are examples of reagents which can be used to introduce fluorine, chlorine, bromine and iodine, respectively. 

Describe the preparation of elemental fluorine, chlorine, bromine, and iodine. 

The halogens include fluorine, chlorine, bromine and iodine and all have been used in CVD reactions. They are reactive elements and exist as diatomic molecules, i.e., F2, CI2, etc. Their relevant properties are listed in Table 3.2. 

Wang, C. Y., Bunday, S. D., and Tartar, J. G., Ion Chromatographic Determination of Fluorine, Chlorine, Bromine, and Iodine with Sequential Electrochemical and Conductometric Detection, Ana/. Chem. 55, 1983, 1617-1619. 

Note that a pair of hydrogen atoms bonded together is a hydrogen molecule. Seven elements, when uncombined with other elements, form diatomic molecules. These elements are hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine. They are easy to remember because the last six form a large 7 in the periodic table ... 

Halon is a halogenated compound that contains elements from the halogen series - fluorine, chlorine, bromine and iodine. Halogen atoms from noncombustible gases when they replace... 

In Tables -A, we report oscillator strengths for some fine structure transitions in neutral fluorine, chlorine, bromine and iodine, respectively. Two sets of RQDO/-values are shown, those computed with the standard dipole length operator g(r) = r, and those where core-valence correlation has been explicitly introduced, Eq. (10). As comparative data, we have included in the tables /-values taken from critical compilations [15,18], results of length and velocity /-values by Ojha and Hibbert [17], who used large configuration expansions in the atomic structure code CIVS, and absolute transition probabilities measured through a gas-driven shock tube by Bengtson et al. converted... 

Fluorine, chlorine, bromine, and iodine react with H S to form the corresponding halogen acid. Metal sullides are formed when H S is passed inlo solutions of the heavy metals, such as Ag. Ph. Cu. and Mn. This rcaelion is responsible lor the tarnishing of Ag and is the hasis for the separation of these metals in classical wet qualitative analytical methods. Hydrogen sullide reacts with many organic compounds. 

The halogen family, fluorine, chlorine, bromine, and iodine has only recently been introduced into atmospheric chemistry.9 The catalytic cycle, with an atom such as Cl in the presence of its monoxide CIO, can... 

Even some elements exist as molecules rather than as atoms. Hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine all exist as diatomic (two-atom) molecules whose two atoms are held together by covalent bonds. We therefore have to write them as such when using any of these elements in a chemical equation. 

Some nonmetals can replace another nonmetal from a compound, too. This replacement is usually limited to the nonmetals called the halogens (fluorine, chlorine, bromine, and iodine). The halogens can be found in Group 17 on the periodic table. The activity of the halogens decreases as you go down Group 17. Fluorine is the most active and iodine is the least. 

Halogen Any member of the nonmetallic elements in Group 17 of the periodic table. It includes the elements fluorine, chlorine, bromine, and iodine. 

Group VII consists of the four elements fluorine, chlorine, bromine and iodine, and the radioactive element astatine. Of these five elements, chlorine, bromine and iodine are generally available for use in school. 

Yoshida M, Takahashi K, Yonehara N, Ozawa T, Iwasaki I (1971) The Fluorine, Chlorine, Bromine, and Iodine Contents of Volcanic Rocks in Japan. Bull Chem Soc Jpn 44 1844... 

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