Functional Groups

Rainbow education*

Elements in Organic CompoundsIn organic molecules,carbon atoms bond with four bonds.mostly with H and other C atoms.sometimes to O, N, S, sometimes to halogens F, Cl, and Br.

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Functional groups area characteristic feature of organic molecules that behave in a predictable, similar way. composed of an atom or group of atoms. groups that replace a hydrogen atom in the corresponding alkane.a way to classify families of organic compounds.Functional Groups*

Alkenes and AlkynesAlkenes contain a double bond between adjacent carbon atoms.(Double bond: 4 electrons)

Alkynes contain a triple bond.(Triple bond: 6 electrons)

Copyright 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings*

Organic compounds with Carbon-Oxygen bonds1. AlcoholsAn alcohol contains the hydroxyl (-OH) functional group.(instead of an H in that place)Copyright 2005 by Pearson Education, Inc.Publishing as Benjamin CummingsEthanol

OH- vs -OHOH- : hydroxide anion found in bases (e.g NaOH)

-OH: hydroxyl group colvalently bound to carbon atom in an organic compound(e.g. ethanol CH3-CH2OH)*

2. Ethers

In an ether, an oxygen atom is bonded to two carbon atoms. COC . has a common name that gives the alkyl names of the attached groups followed by ether.

Copyright 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings*Diethyl ether

3. AldehydesAn aldehyde contains a carbonyl group (C=O), which is a carbon atom with a double bond to an oxygen atom.

*acetaldehydeformaldehyde

4. Ketones

In a ketone, the carbon of the carbonyl group is attached to two other carbon atoms.*Acetone

5. Carboxylic Acids and EstersCarboxylic acids contain the carboxyl group, which is a carbonyl group attached to a hydroxyl group. O COH*Acetic acid

5. EstersAn ester contains the carboxyl group between carbon atoms.*Methyl acetate

Organic compounds with Carbon-Nitrogen bonds1. AminesIn amines, the functional group is a nitrogen atom. H HC N H or C N C

*Methyl amineDimethyl amine

2. Amides

In amides, the hydroxyl group of a carboxylic acid is replaced by a nitrogen group (-NH2).*acetamide

Functional Groups*

Learning CheckClassify each of the following as: alcohol, ether, aldehyde, ketone, carboxylic acid, ester, amine or amide.1)CH3CH2CH2OH2) CH3OCH2CH33) CH3CH2NH2

O O 4) CH3COH 5) CH3COCH3

alcoholetheraminecarboxylic acidester*

Unsaturated Hydrocarbons Cis-Trans Isomers

Chapter 11.2

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Cis and Trans IsomersIn an alkene the double bond, is rigid.holds attached groups in fixed positions. makes cis/trans isomers possible.

CH3CH3 CH3

CH = CH CH = CH cis trans CH3*

In cis-trans isomersthere is no rotation around the double bond in alkenes.groups attached to the double bond are fixed relative to each other.

You can make a double bond with your fingers with both thumbs on the same side or opposite from each other.Cis-Trans Isomers*

Two isomers are possible whengroups are attached to thedouble bond are different.(a double bond cannot rotate)In a cis isomer, groups are attached on the same side of the double bond.

In the trans isomer, the groups are attached on opposite sides.Cis-Trans Isomers*

Cis-Trans IsomerismAlkenes cannot have cis-trans isomers if a carbon atom in the double bond is attached to identical groups. Identical Identical

2-bromopropene 1,1 dibromoethene (not cis or trans) (not cis or trans)

H H H Br*

Cis-Trans Isomers in Nature*

Organic Compounds with Oxygen and Sulfur12.1 Alcohols, Ethers, and Thiols

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AlcoholsAn alcohol contains a hydroxyl group (OH) attached to a carbon chain.

A phenol contains a hydroxyl group (OH) attached to a benzene ring.

water alcohol phenol*

Naming AlcoholsThe names of alcoholsin IUPAC replace the -e with -ol.with common names use the name of the alkyl group followed by alcohol.

FormulaIUPACCommon Name CH4 methaneCH3OH methanol methyl alcoholCH3CH3ethaneCH3CH2OH ethanol ethyl alcohol*

Classification of alcohols isdetermined by the number of alkyl groups attached to the carbon bonded to the hydroxyl.primary (1), secondary (2), or tertiary(3).

Primary (1) Secondary (2) Tertiary (3) 1 group 2 groups 3 groups H CH3 CH3 | | | CH3COH CH3COH CH3COH | | | H H CH3Classification of Alcohols*

ThiolsThiols are carbon compounds that contain a SH group. are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain. not for 10 std.*

ThiolsThiols often have strong odors.

are used to detect gas leaks.

are found in onions, oysters, and garlic.*

Properties of Alcohols, Ethers, and Thiols*

Boiling Points of AlcoholsAlcoholscontain polar OH groups. form hydrogen bonds with other alcohol molecules.have higher boiling points than alkanes and ethers of similar mass.*

Boiling Points of EthersEthersdo not have a polar group.have an O atom, but there is no H attached. cannot form hydrogen bonds between ether molecules.*

Solubility of Alcohols and Ethers in WaterAlcohols and ethers are more soluble in water than alkanes because the oxygen atom can hydrogen bond with water. with 1-4 C atoms are soluble, but not with 5 or more C atoms. *

Comparing Solubility and Boiling Points Molar Boiling Soluble Compound Mass Point (C) in Water?Alkane CH3CH2CH3 44-42 No

Ether CH3OCH3 46-23 Yes

Alcohol CH3CH2OH 4678 Yes

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Solubility of PhenolPhenol is soluble in water. has a hydroxyl group that ionizes slightly (weak acid). is corrosive and irritating to skin.+ H2O + H3O+*

Combustion of AlcoholsAlcohols undergo combustion with O2 to produce CO2 and H2O.

2CH3OH + 3O2 2CO2 + 4H2O + HeatCopyright 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings*

Oxidation and ReductionIn an oxidation, there is an increase in the number of C-O bonds.there is a loss of H.

In a reduction,there is an decrease in the number of C-O bonds.there is a gain of H.*

Oxidation and Reduction *

When a primary alcohol is oxidized, [O],one H is removed from the OH. another H is removed from the carbon bonded to the OH.an aldehyde is produced. [O] Primary alcohol Aldehyde OH O | [O] || CH3CH CH3CH + H2O | H Ethanol Ethanal (ethyl alcohol) (acetaldehyde)Oxidation of Primary (1) Alcohols*

Oxidation of Secondary (2) AlcoholsWhen a secondary alcohol is oxidized, [O],one H is removed from the OH.another H is removed from the carbon bonded to the OH.a ketone is produced. [O] secondary alcohol ketone OH O [O] CH3CCH3 CH3CCH3 + H2O Hisopropyl alcohol dimethyl ketone

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Oxidation of Tertiary AlcoholsTertiary 3alcohols do not readily oxidize. [O]Tertiary alcoholno reaction OH [O] CH3CCH3no product CH3 no H on the C-OH to oxidize

2-methyl-2-propanol

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