1858 ~ 1861, Kekulé, Couper, and Butlerov, laid the basis for one of the most fundamental theories in chemistry: the structural theory. Valence（化合价）: C — tetravalent; O — divalent; H — monovalent
4.1 卤代烃的分类 结构和命名 Classification, Structure, and Nomenclature of Alkyl Halides 4.2 卤代烃的物理性质 Physical Properties of Alkyl Halides 4.3 卤代烃的化学性质 Chemical properties of Alkyl Halides
1.12A The Structure of Methane sp3 Hybridization The 4 sp3 orbitals should be oriented at angles of 109.5° with respect to each other. An sp3-Hybridized carbon gives a tetrahedral structure for methane, and with four equivalent C—H bonds
Isomers are different compounds that have the same molecular formula. Constitutional isomers are isomers that differ because their atoms are connected in a different order. Stereoisomers differ only in arrangement of their atoms in space.Stereoisomers are not constitutional isomers. Enantiomers are stereoisomers whose molecules are nonsuperposable mirror images of each other. Diastereomer are stereoisomers whose molecules are not mirror images of each other
Before 1951 only relative configurations of chiral molecules were known. Configurations of chiral molecules were related to each other through reactions of known stereochemistry. The standard compound was glyceraldehyde
