Organic Chemistry Chapter 12 Copyright o The McGraw-Hill Companies, Inc. Permission required for reproduction or display
Organic Chemistry Chapter 12 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display
Carbon atoms have the ability to link together and form molecules made up of many carbon atoms The branch of chemistry that is the study of carbon-containing compounds is known as organic chemistry(有机化学) 13 million known organic compounds and 100,000 new ones are added annually Only 200,000-300,000 known inorganic compounds
• Carbon atoms have the ability to link together and form molecules made up of many carbon atoms. • The branch of chemistry that is the study of carbon-containing compounds is known as organic chemistry (有机化学). • 13 million known organic compounds and 100,000 new ones are added annually. • Only 200,000-300,000 known inorganic compounds
121 Hydrocarbons(碳氢化合物、烃) contain only carbon and hydrogen Hydrocarbons differ from each other by the number of carbon atoms methane cH4 Octane C8H18 polyethylene
12.1 Hydrocarbons (碳氢化合物、烃) contain only carbon and hydrogen • Hydrocarbons differ from each other by the number of carbon atoms. methane CH4 Octane C8H18 polyethylene
Hydrocarbons differ from each other also by the way carbon atoms connect to each other. Straight-chain hydrocarbon, branched hydrocarbon Molecules having the same chemical formula but different structures are called structural isomers(结构异构体). Structural isomers have different physical and chemical properties. The number of possible structural isomers for a chemical formula increases rapidly as the number of carbon atoms increases: 3 for CeH, 18 for Coha. 75 for C10H22366,319forC20H c624e 33● HHHH H H CH3H H H CH3 H H-C-C-C-C-C-HHCC-C一C一H HC-C-C—H HHHH H CH3 H n-pentane ISo-pentane Neo- pentane
• Hydrocarbons differ from each other also by the way carbon atoms connect to each other. Straight-chain hydrocarbon, branched hydrocarbon • Molecules having the same chemical formula but different structures are called structural isomers (结构异构体). Structural isomers have different physical and chemical properties. The number of possible structural isomers for a chemical formula increases rapidly as the number of carbon atoms increases: 3 for C5H12, 18 for C8H18, 75 for C10H22, 366,319 for C20H42. n-pentane iso-pentane Neo- pentane C H H H C C C C H H H H H H H H H C H H H C C C H CH3 H H H H H C H H H C C H CH3 CH3 H H
Carbon-based molecules can have different spatial orientations called conformations(构象) Fig 12.2 three conformation for a molecule of n-pentane. the molecule looks different in each conformation but the five-carbon framework is the same in all three conformations In a sample of liquid n-pentane the molecules are found in all conformations-not unlike a bucket of worms
Carbon-based molecules can have different spatial orientations called conformations (构象). Fig12.2 three conformation for a molecule of n-pentane. The molecule looks different in each conformation, but the five-carbon framework is the same in all three conformations. In a sample of liquid n-pentane, the molecules are found in all conformations- not unlike a bucket of worms