3 Alkanes08化本.pptVIP

* * 3 Organic Compounds: Alkanes and Their Stereochemistry Based on McMurry’s Organic Chemistry, 7th edition Chemistry and Materials Engineering College Wenzhou University Families of Organic Compounds Organic compounds can be grouped into families by their common structural features 3.1 Functional Groups The chemistry of every compound, regardless of size and complexity, is determined by the functional groups it contain. A characteristic chemical behavior where it occurs. For example, react with bromine in the same way Types of Functional Groups: Multiple Carbon–Carbon Bonds Alkenes have a C-C double bond Alkynes have a C-C triple bond Arenes have special bonds that are represented as alternating single and double C-C bonds in a six-membered ring Functional Groups with Carbon Singly Bonded to an Electronegative Atom Alkyl halide Alcohol Ether Amine Thiol Sulfide Bonds:polar, partial positive charge on C (?+) , partial negative charge (??) on electronegative atom Groups with a Carbon–Oxygen Double Bond (Carbonyl Groups) Aldehyde: Ketone Carboxylic acid Ester Amide Acid chloride Carbonyl C: partial positive charge (?+) Carbonyl O : partial negative charge (?-). Hydrocarbons (烃) C. H elements Aliphatic (脂肪的) Aromatic (芳香的) Cycloalkanes Alkenes Alkynes 3.2 Alkanes and Alkanes Isomers Alkanes Saturated Unsaturated Hydrocarbons Alkanes Alkenes alkynes Four tetrahedral sp3 orbital 3.2 Structures of Alkanes The Structure of ethane C C H H H C C H H H σbond The carbon-carbon bond is formed byσoverlap of 2 carbon sp3 hybrid orbitals An ball-and-stick model of ethane (球棒模型) Shapes of alkanes Zigzag not straight （曲折性） General formula CnH2n+2 for alkanes C3H8 CH3CH2CH3 Propane General formula CnH2n for cycloalkanes (环烷烃） CnH2n Cyclopropane Isomerization of Alkanes n-Pentane Straight-chain ,unbranched alkanes or normal alkanes Isopentane Neopentane Branched-chain alkane Constitutional Isomers (构造异构体) 3.3 Alkyl groups Remo