应用化学专业英语 教学课件 ppt 作者 黄忠 谢普会 付颖 主编lesson 2.ppt

In science, organic can be a biological or chemical term. In biology it means any thing that is living or has lived. The opposite is non-organic. In chemistry, an organic compound is one containing carbon atoms. The opposite term is inorganic. Carbon rings Other Atoms These can contain atoms like phosphorus, sulphur (e.g. thiamine, Vitamin B1), magnesium (e.g. chlorophyll), iron (e.g. haemoglobin), and chlorine (e.g. DDT). Lesson 7 Nomenclature of Organic Compounds In accord with the IUPAC rules, a hydrocarbon is specifically identified by a root, which indicates the number of carbon atoms in the longest continuous chain, and a suffix, which describes the kind of bonds present in the molecule. Prefixes indicate where side chains of carbons or other substituents are attached. Straight-chain hydrocarbons A hydrocarbon in which all carbon atoms are sp3-hybridized is a member of the class of alkanes, designated by the suffix-ane. When a double bond is present, the suffix is-ene, and the compound is an alkene. When a triple bond is present, the suffix is-yne, and the compound is an alkyne. TableⅠ IUPAC Nomenclature for some hydrocarbons to be continued: Branched hydrocarbons For branched hydrocarbons, IUPAC rules dictate that the longest continuous carbon chain be identified as the root, with branching groups named as alkyl substituents. Alkyl groups Alkyl groups with more than two carbons are often designated by common rather than IUPAC names. The common names designate not only the structure of the alkyl group but also the point on the group at which it is attached to the main chain. s- is short for “secondary”, indicating attachment at a secondary carbon-——that is, one attached to two other carbons. Cis and trans isomers However, if two or more groups are present, the relative positions of the groups are fixed: two groups on the same side of the ring are said to be in a cis arrangement; two groups on opposite sides of the ring are said to be in a