Chapter 3 Drawing Chemical StructuresAnd Classification of Organic Chemistry

2.1 Drawing Chemical Structures

2.2 Classification of Organic Chemistry

2.1.4 Hydrocarbons

. . . compounds composed of carbon and hydrogen.

Saturated: carbon-carbon bonds are all single - alkanes [CnH2n+2]

H C

H

H

C

H

H

H

Hydrocarbons(continued)

Unsaturated: contains carbon-carbon multiple bonds.

H C

H

H

C

H

CH

H

Alkanes

the general formula CnH2n+2

saturated hydrocarbons

All the carbon atoms in an alkane are sp3 hybridized and tetrahedral inshape.

Cycloalkanesalicyclic compounds)

the general formula CnH2n

X

Alkyl groups

Alkyl groups (CnH2n+1) are alkane substituents of a complex molecule.

CH3, CH2CH3,CH2CH2CH3,

Classes of Compounds

Classification based on functional group Three broad classes

Hydrocarbons Compounds containing oxygen Compounds containing nitrogen

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2.2 Classification of Organic Chemistry

2.2.1 Hydrocarbons

Alkane: single bonds, sp3 carbons Cycloalkane: carbons form a ring Alkene: double bond, sp2 carbons Cycloalkene: double bond in ring Alkyne: triple bond, sp carbons Aromatic: contains a benzene ring

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2.2.2 Compounds Containing Oxygen

Alcohol: R-OH Ether: R-O-R' Aldehyde: RCHO

Ketone: RCOR'

CH3CH2 C

O

H

CH3 C

O

CH3

=>

2.2.4 The Common Functional Groups

Class General Formula

Halohydrocarbons RX Alcohols ROH Ethers ROR Aldehydes

CRO

H

Class General Formula

Ketones Carboxylic Acids Esters Amines RNH2

CRO

R'

CRO

OH

CRO

O R'

2.2.4 The Common Functional Groups

● functional groups involving double bonds and which contain oxygen

醛

酮

羧酸

酰氯

酸酐

酯

酰胺

酚

ROR醚Ether

Nitrile 睛

Alcohol or akanol 醇

Amine 胺

Nitro 硝基化合物

醛

酮

羧酸

酰氯

酸酐

酯

酰胺

酚

● functional groups which contain a halogen atom

Functional groups can be classed as aliphatic or aromatic.

Aliphatic functional groups(脂肪族官能团）

the aromatic ring is attached to the heteroatom

Aromatic functional groups

the aryl group is directly attached to the carbonyl end of the functional group

Primary( 伯 ), secondary( 仲 ), tertiary( 叔 ), or quaternary( 季 ) nomenclature

The primary (1), secondary (2), tertiary (3) and quaternary (4) nomenclature isused in a variety of situations: to define a carbon center, or to define functionalgroups such as alcohols, halides, amines and amides. Identifying functional groupsin this way can be important since the properties and reactivities of these groupsmay vary depending on whether they are primary, secondary, tertiary, orquaternary.

One of the easiest ways of determining whether a carbon center is 1, 2, 3 or 4 isto count the number of bonds leading from that carbon center to another carbonatom

数 C-C数量

数 N-C数量

Amines and amides

数 C-C数量Alcohols and halides