• To get reactivity out of an organic molecule, functional groups have to be added.

• Functional groups control how a molecule functions.• More complicated functional groups contain elements

other than C or H (heteroatoms).• Functional group containing molecules can either be

saturated (alcohols, ethers, amines etc.) or unsaturated (carboxylic acids, esters, amides, etc.).

• We usually use R to represent alkyl groups.

Functional GroupsFunctional Groups

Alcohols• The functional group of an alcohol is

an -OH group bonded to an sp3 hybridized carbon– bond angles about the hydroxyl oxygen

atom are approximately 109.5°• Oxygen is sp3 hybridized

– two sp3 hybrid orbitals form sigma bonds to carbon and hydrogen

– the remaining two sp3 hybrid orbitals each contain an unshared pair of electrons

108.9°O

CH H

H

H

Nomenclature-Alcohols

• IUPAC names– the parent chain is the longest chain that

contains the OH group– number the parent chain to give the OH group

the lowest possible number– change the suffix -e-e to -ol-ol

• Common names – name the alkyl group bonded to oxygen

followed by the word alcoholalcohol

Nomenclature-Alcohols

• Examples1-Propanol

(Propyl alcohol)2-Propanol

(Isopropyl alcohol)1-Butanol

(Butyl alcohol)

OHOH

OH

2-Butanol(sec-Butyl alcohol)

2-Methyl-1-propanol(Isobutyl alcohol)

2-Methyl-2-propanol(tert-Butyl alcohol)

OHOH

OH

cis-3-Methylcyclohexanol

OHOH

Bicyclo[4.4.0]decan-3-ol

14

58

109 12 2

33

456 7

6

Numbering of thebicyclic ring takes precedence overthe location of -OH

Nomenclature of Alcohols• Compounds containing more than one OH

group are named diols, triols, etc.

CH3CHCH2HO OH

CH2CH2OH OH

CH2CHCH2HO HO OH

1,2-Ethanediol(Ethylene glycol)

1,2-Propanediol(Propylene glycol)

1,2,3-Propanetriol(Glycerol, Glycerine)

Nomenclature of Alcohols

• Unsaturated alcohols – show the double bond by changing the infix

from -an- to -en--en-– show the the OH group by the suffix -ol-ol– number the chain to give OH the lower

number1

2 34 5

6

(E)-2-Hexene-1-ol(trans-2-Hexen-1-ol)

HO

Physical Properties

• Alcohols are polar compounds

– they interact with themselves and with other polar compounds by dipole-dipole interactions

• Dipole-dipole interaction:Dipole-dipole interaction: the attraction between the positive end of one dipole and the negative end of another

O

HH

H

CH

+-

+

Physical Properties

• Hydrogen bondingHydrogen bonding: when the positive end of one dipole is an H bonded to F, O, or N (atoms of high electronegativity) and the other end is F, O, or N– the strength of hydrogen bonding in water is

approximately 21 kJ (5 kcal)/mol– hydrogen bonds are considerably weaker than

covalent bonds– nonetheless, they can have a significant effect on

physical properties

Hydrogen Bonding

Physical Properties

• In relation to alkanes of comparable size and molecular weight, alcohols– have higher boiling points– are more soluble in water

• The presence of additional -OH groups in a molecule further increases solubility in water and boiling point

Physical PropertiesStructural FormulaName

bp(°C)

Solubilityin Water

Methanol 32 65 InfiniteEthane 30 -89 InsolubleEthanol 46 78 InfinitePropane 44 -42 Insoluble1-Propanol 60 97 InfiniteButane 58 0 Insoluble

1-Pentanol 88 138 2.3 g/100 g1,4-Butanediol90 230 Infinite

Hexane 86 69 Insoluble

8 g/100 g117741-ButanolPentane 72 36 Insoluble

CH3CH2 CH2OHCH3CH2 CH2CH3

CH3OHCH3CH3

CH3CH2 OHCH3CH2 CH3

CH3(CH2)3CH2 OHHOCH2(CH2)2CH2 OH

CH3(CH2)4CH3

CH3(CH2)2 CH2OHCH3(CH2)3CH3

MW

Phenols• Alcohol with aromatic ring

Phenols

HO

H2N

2-aminophenol

OHON+

-O

4-nitrophenol

OH

3-butylphenol

Phenols• Ingredients in cloves, vanillia, nutmeg, mint

Thiols: Structure• The functional group of a thiol is an

SHSH (sulfhydrylsulfhydryl) group bonded to an sp3 hybridized carbon

• The bond angle about sulfur in methanethiol is 100.3°, which indicates that there is considerably more p character to the bonding orbitals of divalent sulfur than there is to oxygen

Nomenclature• IUPAC names:

– the parent is the longest chain that contains the -SH group

– change the suffix -e-e to -thiol-thiol– when -SH is a substituent, it is named as a

sulfanyl group• Common names:

– name the alkyl group bonded to sulfur followed by the word mercaptanmercaptan

1-Butanethiol(Butyl mercaptan)

2-Methyl-1-propanethiol(Isobutyl mercaptan)

2-Sulfanylethanol(2-Mercaptoethanol)

SH SH OHHS

Thiols: Physical Properties

• Because of the low polarity of the S-H bond, thiols show little association by hydrogen bonding– they have lower boiling points and are less soluble in

water than alcohols of comparable MW

– the boiling points of ethanethiol and its constitutional isomer dimethyl sulfide are almost identical

1177865

1-ButanolEthanolM ethanol

9835

6

1-ButanethiolEthanethiolM ethanethiol

bp (°C)Alcoholbp (°C)Thiol

CH3CH2SH CH3SCH3Dimethyl sulfide

(bp 37°C)Ethanethiol(bp 35°C)

Thiols: Physical Properties• Low-molecular-weight thiols = STENCH

– the scent of skunks is due primarily to these two thiols

– a blend of low-molecular weight thiols is added to natural gas as an odorant; the two most common of these are

3-Methyl-1-butanethiol(Isopentyl mercaptan)

2-Butene-1-thiolSH

SH

2-Methyl-2-propanethiol(tert-Butyl mercaptan)

2-Propanethiol(Isopropyl mercaptan)

SH SH

Ethers (ROR′)

• Compounds in which two hydrocarbons linked by an oxygen are called ethers.

• Ethers are commonly used as solvents.

Nomenclature: ethers• IUPAC: the longest carbon chain is the parent

– name the OR group as an alkoxy substituent

• Common names: name the groups bonded to oxygen in alphabetical order followed by the word etherether

2-Methoxy-2-methylpropane

(tert- Butyl methyl ether)

Ethoxyethane(Diethyl ether)

CH3

CH3CH3CH2OCH2CH3 CH3OCCH3

trans-2-Ethoxy-cyclohexanol

OCH2CH3

OH

Nomenclature: ethers

• Although cyclic ethers have IUPAC names, their common names are more widely used– IUPAC: prefix ox-ox- shows oxygen in the ring– the suffixes -iraneirane, -etaneetane, -olaneolane, and -aneane

show three, four, five, and six atoms in a saturated ring

Oxirane(Ethylene oxide)

Oxolane(Tetrahydrofuran)

Oxane(Tetrahydropyran)

1,4-DioxaneOO1

2 3

O

O

OOOxetane

Physical Properties

• Although ethers are polar compounds, only weak dipole-dipole attractive forces exist between their molecules in the pure liquid state

Physical Properties• Ethanol and dimethyl ether are constitutional isomers. • Their boiling points are dramatically different

– ethanol forms intermolecular hydrogen bonds which increase attractive forces between its molecules resulting in a higher boiling point

– there is no comparable attractive force between molecules of dimethyl ether

bp -24°CEthanolbp 78° C

Dimethyl ether

CH3CH2OH CH3OCH3

Physical Properties• Boiling points of ethers are

– lower than alcohols of comparable MW– close to those of hydrocarbons of comparable

MW • Ethers are hydrogen bond acceptors

– they are more soluble in H2O than are hydrocarbons

Epoxides• Epoxide:Epoxide: a cyclic ether in which oxygen is one atom of a

three-membered ring– simple epoxides are named as derivatives of oxirane– where the epoxide is part of another ring system, it is

shown by the prefix epoxy-epoxy-– common names are derived from the name of the

alkene from which the epoxide is formally derived

Oxirane(Ethylene oxide)

CH2H2CO1

2 3

cis- 2,3-Dimethyloxirane(cis-2-Butene oxide)

1,2-Epoxycyclohexane(Cyclohexene oxide)

CO

CHCH3HH3C

H

HO

1

2

ClClO

epichlorohydrine

Crown Ethers• Crown ether:Crown ether: a cyclic polyethera cyclic polyether

derived from ethylene glycol or a substituted ethylene glycol– the parent name is crown,

preceded by a number describing the size of the ring and followed by the number of oxygen atoms in the ring

O

OO

O

OO

18-Crown-6

Crown Ethers• The diameter of the cavity

created by the repeating oxygen atoms is comparable to the diameter of alkali metal cations– 18-crown-6 provides very

effective solvation for K+

Thioethers

• The sulfur analog of an ether– IUPAC name: select the longest carbon chain

as the parent and name the sulfur-containing substituent as an alkylsulfanyl group

– common name: list the groups bonded to sulfur followed by the word sulfidesulfide

Ethylsulfanylethane(Diethyl sulfide)

2-Ethylsulfanylpropane(Ethyl isopropyl sulfide)

S S

Disulfide

• Disulfide:Disulfide: contains an -S-S-S-S- group– IUPAC name: select the longest carbon chain

as the parent and name the disulfide-containing substituent as an alkyldisulfanyl group

– Common name: list the groups bonded to sulfur and add the word disulfidedisulfide

Ethyldisulfanylethane(Diethyl disulfide)

SS

Silyl Ethers

Si ClMe

MeMe

Si ClMe

MeSi ClSi Cl

EtEt

EtTrimethylsilyl

chloride(TMSCl)

t-Butyldimethylsilylchloride

(TBDMSCl)

Triisopropylsilylchloride(TIPSCl)

Triethylsilylchloride(TESCl)

Carboxylic Acids• Carboxylic acids contain a carbonyl group with an -OH

attached.• The carboxyl functional group is -COOH:

• Carboxylic acids are weak acids.• Named like alkanes with “-oic acid” at the end.• Typical carboxylic acids are found in spinach, vinegar,

cleaners, vitamin C, aspirin, and citrus fruits.• Carboxylic acids are also used to make polymers for

fibers, paints, and films.

R

O

OH

Compounds with a Compounds with a Carbonyl GroupCarbonyl Group

• The functional group of a carboxylic acid is a carboxyl group

– the general formula for an aliphatic carboxylic acid is RCOOH; that for an aromatic carboxylic acid is ArCOOH

Structure

COOH CO2HO

O HCO

O HAlternative representations for a carboxyl group

Nomenclature - IUPAC• IUPAC names: drop the -ee from the parent

alkane and add the suffix -oic acidoic acid

– if the compound contains a carbon-carbon double bond, change the infix -anan- to -enen-

HCOOH CH3COOH3-Methylbutanoic acid

(Isovaleric acid)Ethanoic acid(Acetic acid)

Methanoic acid(Formic acid)

OH

O

Propenoic acid(Acrylic acid)

trans-3-Phenylpropenoic acid(Cinnamic acid)

trans-2-Butenoic acid(Crotonic acid)

OH

O

OH

OOH

O

Nomenclature - IUPAC

• The carboxyl group takes precedence over most other functional groups

5-Oxohexanoic acid 4-Aminobutanoic acid(R)-5-Hydroxyhexanoicacid

OH O

OH

O

OH

OH2N OH

O

Nomenclature - IUPAC

– dicarboxylic acids: add the suffix -dioic aciddioic acid to the name of the parent alkane containing both carboxyl groups

HO OH

O

Propanedioic acid(Malonic acid)

Ethanedioic acid(Oxalic acid)

OHO OH

O

O

Hexanedioic acid(Adipic acid)

Pentanedioic acid(Glutaric acid)

Butanedioic acid(Succinic acid)

OOH

OHOOH

O

HO

OHO OH

O

O

Nomenclature - IUPAC– if the carboxyl group is bonded to a ring, name the

ring compound and add the suffix -carboxylic acidcarboxylic acid

– benzoic acid is the simplest aromatic carboxylic acid– use numbers to show the location of substituents

COOH COOHHOOC32

1

2-Cyclohexenecarboxylicacid

trans-1,3-Cyclopentanedicarboxylicacid

COOH COOHOH COOH

COOHCOOH

COOHBenzoic

acid2-Hydroxybenzoic

acid(Salicylic acid)

1,2-Benzenedicarboxylic acid

(Phthalic acid)

1,4-Benzenedicarboxylic acid

(Terephthalic acid)

Nomenclature-Common

– when common names are used, the letters etc. are often used to locate substituents

L-alanine][(S)--Aminopropionic acid;(-Aminobutyric acid, GABA)(S)-2-Aminopropanoic acid4-Aminobutanoic acid

4 3 25H2N OH

OOH

O

NH2OH

O

1

Physical Properties

• In the liquid and solid states, carboxylic acids are associated by hydrogen bonding into dimeric structures

Physical Properties• Carboxylic acids have significantly higher boiling points

than other types of organic compounds of comparable molecular weight– they are polar compounds and form very strong

intermolecular hydrogen bonds• Carboxylic acids are more soluble in water than alcohols,

ethers, aldehydes, and ketones of comparable molecular weight– they form hydrogen bonds with water molecules

through their C=O and OH groups

Physical Properties

• Table 17.2

CH3COOHCH3CH2CH2OHCH3CH2CHO

CH3(CH2)2COOHCH3(CH2)3CH2OHCH3(CH2)3CHO

CH3(CH2)4COOHCH3(CH2)5CH2OHCH3(CH2)5CHO

Acetic acid1-PropanolPropanal

60.160.158.1

1189748

16388.1Butanoic acid1-Pentanol 88.1 137

103Pentanal 86.1

Heptanal 153176116.21-Heptanol

Hexanoic acid 116.2 205

114.1

Structure Name

MolecularWeight(g/mol)

Boiling Point(°C)

Solubility(g/100 g H2O)

InfiniteInfinite16

Infinite2.3Slight

1.00.20.1

Physical Properties

– water solubility decreases as the relative size of the hydrophobic portion of the molecule increases

EXERCICES

Aldehydes and Ketones• The carbonyl functional group is C=O.• Aldehydes must have at least one H atom attached to the

carbonyl group:

• Ketones must have two C atoms attached to the carbonyl group:

• Aldehydes and ketones are prepared from the oxidation of alcohols.

Compounds with a Compounds with a Carbonyl GroupCarbonyl Group

R

O

H

R

O

R'

Structure– the functional group of an aldehyde is a

carbonyl group bonded to a H atom and a carbon atom

– the functional group of a ketone is a carbonyl group bonded to two carbon atoms

Propanone(Acetone)

Ethanal(Acetaldehyde)

Methanal(Formaldehyde)

OO O

CH3CHHCH

CH3CCH3

Nomenclature

• IUPAC names:– the parent chain is the longest chain that

contains the functional group– for an aldehyde, change the suffix from -e-e to -al-al– for an unsaturated aldehyde, change the infix

from -an--an- to -en--en-; the location of the suffix determines the numbering pattern

– for a cyclic molecule in which -CHO is bonded to the ring, add the suffix -carbaldehydecarbaldehyde

Nomenclature: Aldehydes

– the IUPAC retains the common names benzaldehyde and cinnamaldehyde, as well formaldehyde and acetaldehyde

H

O

3-Methylbutanal 2-Propenal(Acrolein)

(2E)-3,7-Dimethyl-2,6-octadienal(Geranial)

1

2

3

4

5

6

78H

O

H

O

CHO HO CHOCyclopentane-carbaldehyde

trans-4-Hydroxycyclo-hexanecarbaldehyde

14

CHOC6H5CHO

trans-3-Phenyl-2-propenal(Cinnamaldehyde)

Benzaldehyde

Nomenclature: Ketones• IUPAC names

– the parent alkane is the longest chain that contains the carbonyl group

– indicate the ketone by changing the suffix -e-e to -one-one – number the chain to give C=O the smaller number– the IUPAC retains the common names acetone,

acetophenone, and benzophenone

Propanone(Acetone)

Benzophenone 1-Phenyl-1-pentanoneAcetophenone

O O OO

Common Names– for an aldehyde, the common name is derived

from the common name of the corresponding carboxylic acid

– for a ketone, name the two alkyl or aryl groups bonded to the carbonyl carbon and add the word ketone

HCHO

HCOHO

CH3CHO

CH3COHO

Formaldehyde Formic acid Acetaldehyde Acetic acid

Ethyl isopropyl ketone Diethyl ketone Dicyclohexyl ketone

O OO

Physical Properties• Oxygen is more electronegative than carbon (3.5 vs 2.5) and,

therefore, a C=O group is polar

– aldehydes and ketones are polar compounds and interact in the pure state by dipole-dipole interaction

– they have higher boiling points and are more soluble in water than nonpolar compounds of comparable molecular weight

Esters

• The functional group of an ester is an acyl group bonded to -OR or -OAr– name the alkyl or aryl group bonded to

oxygen followed by the name of the acid – change the suffix -ic acid-ic acid to -ate-ate

O

OEtO

O

OEtO

O

O

Ethyl ethanoate(Ethyl acetate)

Diethyl butanedioate(Diethyl succinate)

Isopropyl benzoate

Esters• Some common esters are: benzocaine (in sun burn

lotions), ethyl acetate (nail polish remover), vegetable oils, polyester thread, and aspirin.

• Esters contain -COOR groups:

• Esters can be prepared by reacting a carboxylic acid with an alcohol and eliminating water:

R

O

OR'

OHH3CCO

HO CH2CH3OCH2CH3H3C

CO

H2O+ +

• Esters are named first using the alcohol part and then the acid part (in the above example: ethyl from ethanol and acetate from acetic acid).

• In the presence of base, esters hydrolyze (molecule split into acid and alcohol). – REVERSE OF ESTERIFICATION

• Saponification is the hydrolysis of an ester in the presence of a base.

• Esters tend to have characteristic odors and are used as food flavorings and scents.

Esters

• Cyclic esters are called lactoneslactones– name the parent carboxylic acid, drop the

suffix -ic acid-ic acid and add -olactone-olactone

4-Butanolactone-Butyrolactone)

3-Butanolactone-Butyrolactone)

O OO O

H3C23

1213 4

6-Hexanolactone-Caprolactone)

O

O2 13

45 6

Lipids• Lipids:Lipids: a heterogeneous class of naturally

occurring organic compounds classified together on the basis of common solubility properties– they are insoluble in water but soluble in

aprotic organic solvents, including diethyl ether, methylene chloride, and acetone

• Lipids include– triglycerides, phospholipids, prostaglandins,

prostacyclins, and fat-soluble vitamins– cholesterol, steroid hormones, and bile acids

Triglycerides

• Triglyceride:Triglyceride: an ester of glycerol with three fatty acids

A triglyceride

CH2OCR

CH2OCR''R'COCH 1. NaOH, H2O

2. HCl, H2O

CH2OH

CH2OH 1,2,3-Propanetriol(Glycerol, glycerin)

+RCOOHR'COOHR''COOHFatty acids

OHOCH

O

O

Fatty Acids• Fatty acid:Fatty acid: an unbranched chain carboxylic acid derived

from hydrolysis of animal fats, vegetable oils, or membrane phospholipids– nearly all have an even number of carbon atoms, most

between 12 and 20, in an unbranched chain– the three most abundant are palmitic (16:0), stearic acid

(18:0), and oleic acid (18:1)– in most unsaturated fatty acids, the cis isomer

predominates; the trans isomer is rare– unsaturated fatty acids have lower melting points than

their saturated counterparts; the greater the degree of unsaturation, the lower the melting point

Unsaturated Fatty Acids

Saturated Fatty Acids

20:418:318:218:116:1

20:018:016:014:012:0

Carbon Atoms/Double Bonds*

Melting Point(°C)

Common Name

-49-11-5161

7770635844

Arachidonic acidLinolenic acidLinoleic acidOleic acidPalmitoleic acid

Arachidic acidStearic acidPalmitic acidMyristic acidLauric acid

Triglycerides• Physical properties depend on the fatty acid components

– melting point increases as the number of carbons in its hydrocarbon chains increases and as the number of double bonds decreases

– triglycerides rich in unsaturated fatty acids are generally liquid at room temperature and are called oilsoils

– triglycerides rich in saturated fatty acids are generally semisolids or solids at room temperature and are called fatsfats

Triglycerides• The lower melting points of triglycerides rich in

unsaturated fatty acids are related to differences in their three-dimensional shape– hydrocarbon chains of saturated fatty acids can lie

parallel with strong dispersion forces between their chains; they pack into well-ordered, compact crystalline forms and melt above room temperature

– because of the cis configuration of the double bonds in unsaturated fatty acids, their hydrocarbon chains have a less ordered structure and dispersion forces between them are weaker; these triglycerides have melting points below room temperature

Soaps and Detergents

• Natural soaps are prepared by boiling lard or other animal fat with NaOH, in a reaction called saponification (Latin, sapo, soap)

Sodium soaps

1,2,3-Propanetriol(Glycerol; Glycerin)

A triglyceride(a triester of glycerol)

+

saponification+CHCH2OCR

CH2OCRCHOHCH2OH

CH2OHRCO 3NaOH

3RCO- Na+

O

OO

O

Esters of Phosphoric Acid– phosphoric acid forms mono-, di-, and triesters– name by giving the name of the alkyl or aryl group(s)

bonded to oxygen followed by the word phosphatephosphate– in more complex phosphoric esters, it is common to

name the organic molecule and then indicate the presence of the phosphoric ester by the word phosphatephosphate or the prefix phospho-phospho-

OCH3

CH3OPOHO C-H

CH2-O-P-O-

CHOHO

O-

O

N

HO

H3C

CH2O-P-O-

O-

CHO OCO-

CCH2

O P O-

O-

OO

Dimethylphosphate

Glyceraldehyde3-phosphate

Pyridoxal phosphate Phosphoenol-pyruvate

Phospholipids• Phospholipids are the second most abundant group of

naturally occurring lipids– they are found almost exclusively in plant and animal

membranes, which typically consist of 40% -50% phospholipids and 50% - 60% proteins

– the most abundant phospholipids are derived from phosphatidic acid, a molecule in which glycerol is esterified with two molecules of fatty acid and one of phosphoric acid

– the three most abundant fatty acids in phosphatidic acids are palmitic acid (16:0), stearic acid (18:0), and oleic acid (18:1)

Phospholipids

• A phosphatidic acid

– further esterification with a low-molecular weight alcohol gives a phospholipid

– among the most common of these low-molecular-weight alcohols are

CH2

CHCH2-O-P-O-

OO

O

O glycerolpalmitic acid

stearic acid O

O-

Phospholipids

– among the most common of these low-molecular-weight alcohols are

Ethanolamine

+Choline Phosphatidylcholine

(Lecithin)

Phosphatidylethanolamine(Cephalin)

Serine Phosphatidylserine

Inositol Phosphatidylinositol

NH3+

HOHO

OHOH

OHHO

HOCH2CHCOO-

HOCH2CH2N(CH3)3

HOCH2CH2NH2

Phospholipids

• A lecithin

in aqueous solution, phospholipids spontaneously form into a lipid bilayer, with a back-to-back arrangement of lipid monolayers

CH2

CHCH2

OO

O

O

O P OCH2CH2N(CH3)3

O

O-

+

palmitic acid

stearic acid

glycerol

choline

Biological Membranes

a biological membrane consists of a phospholipid bilayer with proteins, carbohydrates, and other lipids embedded on the surface and in the bilayer

Structure & Classification• Amines are classified as

– 1°, 2°, or , 3° amines:1°, 2°, or , 3° amines: amines in which 1, 2, or 3 hydrogens of NH3 are replaced by alkyl or aryl groups

Methylamine(a 1° amine)

Dimethylamine(a 2° amine)

Trimethylamine(a 3° amine)

CH3 -NH2 CH3 -NH CH3 -NCH3 CH3

CH3: :

:

Structure & Classification• Amines are further divided into aliphatic,

aromatic, and heterocyclic amines:– aliphaticaliphatic amine:amine: an amine in which nitrogen is bonded

only to alkyl groups– aromatic amine:aromatic amine: an amine in which nitrogen is bonded

to one or more aryl groups

Aniline(a 1° aromatic amine)

N-Methylaniline(a 2° aromatic amine)

B enzyldimethylamine(a 3° aliphatic amine)

NH2 N-H CH2 -N-CH3

CH3 CH3

::

:

Structure & Classification

– heterocyclic amine:heterocyclic amine: an amine in which nitrogen is one of the atoms of a ring

PyrrolePiperidinePyrrolidine Pyridine(heterocyclic aliphatic amines) (heterocyclic aromatic amines)

NN NH H

NH

Structure & ClassificationExample:Example: classify each amino group by type

O

O C6H5

NCH3

COOCH3

HN

H

N

NCH3

H

(b)

(S)-Coniine

(a)

Cocaine(S)-Nicotine

(c)

Structure & Classification

• Aliphatic amines: replace the suffix -ee of the parent alkane by -amineamine

1,6-Hexanediamine(S)-1-Phenyl-ethanamine

2-Propanamine

NH2

NH2

NH2H2N

1

Nomenclature

• The IUPAC system retains the name aniline

3-Methoxyaniline(m- Anisidine)

4-Methylaniline(p-Toluidine)

Aniline 4-Nitroaniline(p- Nitroaniline)

NH2 NH2

CH3OCH3

NH2

NO2

NH2

Nomenclature

• Among the various functional groups discussed in the text, -NH2 is one of the lowest in order of precedence

COOHH2NOHNH2

H2N OH

4-Aminobenzoic acid2-Aminoethanol (S)-2-Amino-3-methyl-1-butanol

Nomenclature

• Common names for most aliphatic amines are derived by listing the alkyl groups bonded to nitrogen in one word ending with the suffix -amineamine

CH3NH2 NH

Et3NNH2

TriethylamineDicyclopentylamineMethylamine tert-Butylamine

Nomenclature

• When four groups are bonded to nitrogen, the compound is named as a salt of the corresponding amine

Me4N+ Cl - NCH2(CH2)12CH3

Cl -

Ph CH2NMe3 OH-+

Benzyltrimethyl-ammoniumhydroxide

Tetramethyammonium

chloride

Tetradecylpyridinium chloride(Cetylpyridinium chloride)

Physical Properties

• Amines are polar compounds, and both 1° and 2° amines form intermolecular hydrogen bonds– N-H- - -N hydrogen bonds are weaker than O-

H- - -O hydrogen bonds because the difference in electronegativity between N and H (3.0 - 2.1 =0.9) is less than that between O and H (3.5 - 2.1 = 1.4)

bp (°C) -6.3 65.0-88.632.031.130.1MW (g/mol)

CH3CH3 CH3NH2 CH3OH

Amides

• The functional group of an amide is an acyl group bonded to a nitrogen atom– IUPAC: drop -oic acidoic acid from the name of the

parent acid and add -amide-amide– if the amide nitrogen is bonded to an alkyl or

aryl group, name the group and show its location on nitrogen by NN--

CH3CNH2O

CH3C-NH

CH3

OH-C-N

CH3

CH3

O

N-Methylacetamide(a 2° amide)

Acetamide(a 1° amide)

N,N-Dimethyl-formamide (DMF)

(a 3° amide)

Amides

• Cyclic amides are called lactams– name the parent carboxylic acid, drop the

suffix -ic acid-ic acid and add -lactam-lactam

6-Hexanolactam-Caprolactam)

H3C

O

NH

O

NH1

2 123

45 63

3-Butanolactam-Butyrolactam)

Amino Acids

• Amino acid:Amino acid: a compound that contains both an amino group and a carboxyl group -Amino acid:-Amino acid: an amino acid in which the

amino group is on the carbon adjacent to the carboxyl group

– although -amino acids are commonly written in the unionized form, they are more properly written in the zwitterionzwitterion (internal salt) form

RCHCOHNH2

ORCHCO-

NH3+

O

Nonpolar side chains

NH3+

COO-

NH3+

COO-

NH3+

COO-

NH3+

COO-

NH3+

COO-S

NH3+

COO-

NH H

COO-

NH3+

COO-

NH

COO-

NH3+

Alanine (Ala, A)

Glycine (Gly, G)

Isoleucine (Ile, I)

Leucine (Leu, L)

Methionine (Met, M)

Phenylalanine (Phe, F)

Proline (Pro, P)

Tryptophan (Trp, W)

Valine (Val, V)

Polar side chains

NH3+

COO-H2N

O

NH3+

COO-H2N

ONH3

+

COO-HO

NH3+

COO-OH

Asparagine (Asn, N)

Glutamine (Gln, Q)

Serine (Ser, S)

Threonine (Thr, T)

Acidic & basic side chainsNH3

+

COO--O

O

NH3+

COO--O

O

NH3+

COO-HS

NH3+

COO-

HO

NH3+

COO-NH

H2N

NH2+

NH3+

COO-N

NH

NH3+

COO-H3N

Cysteine (Cys, C)

Tyrosine (Tyr, Y)

Glutamic acid (Glu, E)

Aspartic acid (Asp, D)

Histidine (His, H)

Lysine (Lys, K)

Arginine (Arg, R)

+

Other Amino Acids

NH3+

COO-NH

H2NO

NH3+

COO-H3N

HO O CH2CHCOO-

NH3+

I I

I I

NH3+

-O

O

L-CitrullineL-Ornithine

L-Thyroxine, T4 4-Aminobutanoic acid(-Aminobutyric acid, GABA)

+

Imides

• The functional group of an imide is two acyl groups bonded to nitrogen– both succinimide and phthalimide are cyclic

imides

PhthalimideSuccinimide

NH NH

O O

OO

Nitriles

• The functional group of a nitrile is a cyano group– IUPAC names: name as an alkanenitrilealkanenitrile– common names: drop the -ic acid-ic acid and add --

onitrileonitrile

CH3C N C N CH2C N

Ethanenitrile(Acetonitrile)

Benzonitrile Phenylethanenitrile(Phenylacetonitrile)

Isocyanates

• -N=C=O• CH3 –NCO methylisocyanate

• IPDI• HDI OCN-(CH2)6-NCO

• TDI• MDI

HaloalkanesHaloalkanes

Structure• Haloalkane (alkyl halide):Haloalkane (alkyl halide): a compound containing a

halogen covalently bonded to an sp3 hybridized carbon; given the symbol RX

• Haloalkene (vinylic halide):Haloalkene (vinylic halide): a compound containing a halogen bonded to an sp2 hybridized carbon

• Haloarene (aryl halide):Haloarene (aryl halide): a compound containing a halogen bonded to a benzene ring; given the symbol ArX

Nomenclature– number the parent chain to give the substituent

encountered first the lowest number, whether it is halogen or an alkyl group

– indicate halogen substituents by the prefixes fluoro-, chloro-, bromo-, and iodo-, and list them in alphabetical order with other substituents

– locate each halogen on the parent chain by giving it a number preceding the name of the halogen

– in haloalkenes, number the parent chain to give carbon atoms of the double bond the lower set of numbers

Nomenclature

– examples

• Common names:Common names: name the alkyl group followed by the name of the halide

Br

2-Bromo-4-methyl-pentane

1234

54-Bromo-

cyclohexene

1

23

4

56

trans-2-Chloro-cyclohexanol

Br Cl

OH

Br Cl Cl

2-Bromobutane(sec-Butyl bromide

Cnhloroethene(Vinyl chloride)

3-Chloropropene(Allyl chloride)

Nomenclature

– several polyhaloalkanes are common solvents and are generally referred to by their common or trivial names

– hydrocarbons in which all hydrogens are replaced by halogens are commonly named as perhaloalkanes or perhaloalkenes

CHCl3CH2Cl2 CCl2=CHClCH3CCl3 Dichloromethane(Methylene chloride)

Trichloromethane (Chloroform)

Trichloroethyne (Trichlor)

1,1,1-Trichloroethane (Methyl chloroform)

PerchloroethylenePerfluoropropanePerchloroethane

C CCl

ClClCl

ClCl

F C C C FF

F

F

F

F

F ClC C

Cl

ClCl

Dipole Moments

• Dipole moment of RX depends on:– the sizes of the partial charges – the distance between them – the polarizability of the unshared electrons on

halogen

CH3ClCH3F

CH3BrCH3I

Halomethane Electronegativityof Halogen

Carbon-HalogenBond Length

(pm)

Dipole Moment

(debyes; D)4.03.02.82.5

139178193214

1.851.871.811.62

van der Waals Forces• Haloalkanes are associated in the liquid state by van der

Waals forces• van der Waals forces:van der Waals forces: a group intermolecular attractive

forces including – dipole-dipole forces– dipole-induced dipole forces– induced dipole-induced dipole (dispersion) forces

• van der Waals forces pull molecules together– as molecules are brought closer and closer, van der

Waals attractive forces are overcome by repulsive forces between electron clouds of adjacent atoms or molecules

Boiling Points• For an alkane and a haloalkane of comparable size and

shape, the haloalkane has the higher boiling point– the difference is due almost entirely to the greater

polarizability of the three unshared pairs of electrons on halogen compared with the low polarizability of shared electron pairs of covalent bonds

– polarizability:polarizability: a measure of the ease of distortion of the distribution of electron density about an atom in response to interaction with other molecules and ions; fluorine has a very low polarizability, iodine has a very high polarizability

CH3CH3 CH3Brbp -89°C bp 4°C

Boiling Points

– among constitutional isomers, branched isomers have a more compact shape, decreased area of contact, decreased van der Waals attractive forces between neighbors, and lower boiling points

2-Bromo-2-methylbutanebp 72°C

Br

1-Bromobutanebp 100°C

Br

Boiling Points– boiling points of fluoroalkanes are comparable to

those of hydrocarbons of similar molecular weight and shape

– the low boiling points of fluoroalkanes are the result of the small size of fluorine, the tightness with which its electrons are held, and their particularly low polarizability

Hexane(MW 86.2, bp 69°C)

F1-Fluoropentane

(MW 90.1, bp 63°C)

CH3CHCH3

CH3CH3CHCH3

F

2-FluoropropaneMW 62.1, bp -11°C

2-MethylpropaneMW 58.1, bp -1°C

Density• The densities of liquid haloalkanes are greater than

those of hydrocarbons of comparable molecular weight– a halogen has a greater mass per volume than a

methyl or methylene group• All liquid bromoalkanes and iodoalkanes are more dense

than water• Di- and polyhalogenated alkanes are more dense than

water

CHX3

CH2X2

CX4

Cl Br IX=

1.4832.497

4.008

Density (g/mL) at 25°C

3.3252.890

1.594 3.273 4.23

Haloalkane1.327

Bond Lengths, Strengths

• C-F bonds are stronger than C-H bonds; C-Cl, C-Br, and C-I bonds are weaker

C-HC-F

C-ClC-BrC-I

Bond

BondLength(pm)

Bond Dissociation Ethalpy

[kJ (kcal)/mol]

109142

178193214

414 (99)464 (111)

355 (85)309 (78)228 (57)