halogen Chem.
(ˈhæləʊdʒɛn)
[mod. f. Gr. ἅλς, ἁλο- salt + -gen; cf. F. halogène]
An element or substance which forms a salt by direct union with a metal. The halogens are chlorine, fluorine, bromine, iodine, and the compound cyanogen. In mod. use, any of the elements of group 7 of the periodic table, viz. fluorine, chlorine, bromine, iodine, and astatine.
| 1842 Proc. Amer. Phil. Soc. II. 219 The epithet halogen is applied to bodies whose binary compounds with metals are deemed salts. 1867 C. L. Bloxam Chem. 10 A salt-radical or halogen is a substance which forms an acid when combined with hydrogen. Examples.—Chlorine, which forms hydrochloric acid (HCl); Cyanogen (C2N), which forms hydrocyanic acid (HC2N). 1872 Watts Dict. Chem. III. 6 Halogen, the electro-negative radicle of an haloïd-salt. 1880 Nature XXI. 290 Displacement between oxygen and the halogen elements united with metals. 1884 T. S. Humpidge tr. Kolbe's Short Text-bk. Inorg. Chem. 96 The halogens or salt-producers. The four elements chlorine, bromine, iodine, and fluorine are grouped together under this name. 1959 Nomencl. Inorg. Chem. (I.U.P.A.C.) 6 The use of the collective names: halogens (F, Cl, Br, I, and At),..may be continued. |
Hence haˈlogenated a., combined with a halogen. halogeˈnation, the introduction of an atom of a halogen into a molecule of a compound by addition or substitution. haˈlogenous a., of the nature of a halogen.
| 1846 Smart Suppl. s.v., The simple halogenous bodies or halogens at present known, are chlorine, fluorine, iodine and bromine. 1882 Nature XXV. 353 The action of halogenated..radicals on the potassic compound of pyrol. 1911 Chem. Abstr. V. 1436 (heading) Halogenation of benzene monohalides... The expts...were carried out at 55–75° without a diluent. 1965 Phillips & Williams Inorg. Chem. II. xii. 463 Some of the interhalogens provide convenient solvents for halogenation reactions, particularly in view of their partial ionization. |