7.2 The Stereogenic Center (a) Structures A and B are mirror-image representations of bromochlorofluoromethane(BrCIFCH) (b) To test for superposability, reorient B by turning it 180 tumn180° B (c)C A and B. The two do not match. A and B cannot be superposed on each other. a chiral molecule. The two mirror-image forms are of each other two mirror-image forms are not superposable. groups FIGURE 7. 1 A molecule with four different groups attached to a single carbon is chiral. Its are chiral when w, x, v, and z are different substituents. a tetrahedral carbon atom that bears four different substituents is variously referred to as a chiral center, a chiral car- 1987 issue of the Joumal of bon atom, an asymmetric center, or an asymmetric carbon atom. A more modern term Chemical Education gives a is stereogenic center, and that is the term that we'll use (Stereocenter is synonymous horough discussion of molec- ar chirality and with stereogenic center:) past and present terminal- Back Forward Main MenuToc Study Guide ToC Student o MHHE Websiteare chiral when w, x, y, and z are different substituents. A tetrahedral carbon atom that bears four different substituents is variously referred to as a chiral center, a chiral car￾bon atom, an asymmetric center, or an asymmetric carbon atom. A more modern term is stereogenic center, and that is the term that we’ll use. (Stereocenter is synonymous with stereogenic center.) 7.2 The Stereogenic Center 261 (a) Structures A and B are mirror-image representations of bromochlorofluoromethane (BrClFCH). (b) To test for superposability, reorient B by turning it 180°. (c) Compare A and B. The two do not match. A and B cannot be superposed on each other. Bromochlorofluoromethane is therefore a chiral molecule. The two mirror-image forms are enantiomers of each other. B A A B Br Cl H F Br Cl H F Br Cl H F A Br Cl H F Br Cl H F B Br Cl H F turn 180° FIGURE 7.1 A molecule with four different groups attached to a single carbon is chiral. Its two mirror-image forms are not superposable. An article in the December 1987 issue of the Journal of Chemical Education gives a thorough discussion of molec￾ular chirality and some of its past and present terminol￾ogy. Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website