1.1 : 什么是有机化学？

Organic chemistry is the study of chemical compounds composed primarily of carbon atoms bonded to hydrogen, oxygen, nitrogen, or sulfur atoms.

Organic compounds form a vast variety of molecules—from fundamental building blocks of life like DNA or plant cell walls to energy-liberating materials like fuels. They are usually easily broken down.

Carbon atoms constitute the backbone of every organic compound, which can assume diverse structures with ring-shaped, branched, and straight-chain arrangements due to carbon’s versatility in forming four bonds as either single, double, or triple bonds. 

Organic compounds can be either hydrocarbons or functionalized hydrocarbons.

Hydrocarbons are constituted entirely of carbon and hydrogen atoms. Alkanes are hydrocarbons containing single bonds. Alkenes contain one or more double bonds, while alkynes contain one or more triple bonds.

Hydrocarbons with one or more of their hydrogen atoms substituted by a specific group of atoms or functional groups are called ‘functionalized hydrocarbons’. The general formula of functionalized hydrocarbons designates the hydrocarbon portion by the letter ‘R’, followed by the specific functional group.

Functional groups can be of many types and have specific physical and chemical properties. All organic compounds carrying a common functional group fall under the same family of hydrocarbons, exhibit similar properties, and follow similar nomenclature.

For instance, all organic compounds with a carbon atom carrying an –OH functional group are called alcohols. In contrast, all organic compounds carrying carboxyl functional groups are called carboxylic acids.

Overall, understanding the structure, bonding, and reactions of organic compounds, both natural and man-made, is key to understanding their functions in real life.