ORGANIC FUNCTIONAL GROUPS AND NOMENCLATURE

ALKYL GROUPS• An alkyl group is an unbranched alkane

with a hydrogen atom removed from the terminal, or end, carbon.

• To name the alkyl group, replace the –ane ending of the unbranched alkane with –yl.

• Thus, if you take one hydrogen from CH4, it becomes —CH3, and the name changes from methane to methyl.

Alkane

Molecular Formula

Structural Formula Alkyl

Molecular Formula

Methane CH4 CH4 Methyl CH3

Ethane C2H6 CH3CH3 Ethyl C2H5

Propane C3H8 CH3CH2CH3 Propyl C3H7

Butane C4H10 CH3(CH2)2CH3 Butyl C4H9

Pentane C5H12 CH3(CH2)3CH3 Pentyl C5H11

Hexane C6H14 CH3(CH2)4CH3 Hexyl C6H13

Heptane C7H16 CH3(CH2)5CH3 Heptyl C7H15

Oktane C8H18 CH3(CH2)6CH3 Oktyl C8H17

Nonane C9H20 CH3(CH2)7CH3 Nonyl C9H19

Dekane C10H22 CH3(CH2)8CH3 Dekyl C10H21

Undekane C11H24 CH3(CH2)9CH3 Undekyl C11H23

Dodekane C12H26 CH3(CH2)10CH3 Dodekyl C12H25

NAMES OF ALKANES and ALKYL GROUPS

ALKYL GROUPS ANIMATION

•  

• Carbon atoms are classified as primary, secondary, tertiary, or quaternary based on the number of non-hyrogen groups attached to the sp3 carbon. • The hydrogen atoms attached to these carbon atoms are given the same designation.

Primary,secondary and tertiary carbon atoms

• Organic compounds often contain functional groups bonded on to different types of carbon chains.

• These can often be usefully distinguished using the terms primary,secondary and tertiary.

• Primary means that the carbonthat the functional group is joined to is bonded to only one other carbon atom

• Secondary means that it is bondedto two other carbon atoms

• Tertiary three other carbon atoms.

METYL,ETHYL and PROPYL GROUPS

methyl

H |

H-C- | H

ethyl

H H | |

H-C-C- | | H H

n-propyl or simply propyl

H H H | | |

H-C-C-C- | | | H H H

isopropyl

H H H | | |

H-C-C-C-H | | | H H

The skeletal structural formulas shown here are intended to emphasize the fact that the n-propyl and isopropyl groups can be drawn in a variety of orientations.

It is not the way that the Cs are drawn that makes the difference.

It is the location of the bond to something else that distinguishes n-propyl from isopropyl.

Starting from the bonding point in a normal propyl group there is a continuous string of three carbon atoms.

Starting from the bond point in an isopropyl group the three carbon atoms are not continuous, instead they are branched.

n-propyl isopropyl

DRAWING PROPYL GROUPS IN A VARIETY OF ORIENTATIONS

BUTYL GROUPS The next set of alkyl groups contains four carbons. That is why they are called butyl groups. There are four types of butyl groups each with a different combination of carbon chain and bonding point.

The first one is a straight chain with an H missing from the end and is called a normal butyl group (or n-butyl group).

n-butyl or

butyl The next one is iso-butyl (usually spelled isobutyl). It has a branched chain at the end opposite where it attaches to something else.

iso-butyl or

isobutyl

There is also a secondary-butyl which is often referred to as sec-butyl. Its structural arrangement is shown here.

sec-butyl

Also, tertiary-butyl (also called tert-butyl or t-butyl) has a fourth kind of arrangement as shown.

tert-butyl or

t-butyl

TRIVIAL(COMMON) AND IUPAC NAMES OF COMMON ALKYL GROUPS

PENTYL GROUPS

There are eight different pentyl groups (-C5H11), but only four of these have trivial names. These four are shown above.

ALKYL GROUP

• Note that an alkyl group (CnH2n+1, like an alkane with one H removed) can be represented by R.

• Thus alcohols (which contain the hydroxyl group — OH) can be represented as ROH.

• Similarly the benzene ring can be represented as so that phenol (a benzene ring with an — OH attached) is represented as

ALKENYL GROUP

• An alkenyl group is a hydrocarbon group formed when a hydrogen atom is removed from an alkene group.

• Alkenyl compounds are named by replacing the -e from the parent alkene's name with -yl.

• H2C=CH- (ethenyl or commonly known as vinyl). The parent alkene was H2C=CH2, ethene.

ALKYNYL GROUP

• An alkynyl group is a hydrocarbon group formed when a hydrogen atom is removed from an alkyne group.

• Alkenyl compounds are named by replacing the -e from the parent alkyne's name with -yl.

• ethynyl group, H C C derived from ethyne, H C C H is also called ethynyl radical.

AROMATICS (ARENES) • Arenes are cyclic hydrocarbons that contain three

single bonds and three double bonds conjugated in a six-carbon ring.

• Arenes are usually derived from benzene.• Another commonly used name for arenes is

aromatic hydrocarbons. • Arenes are cyclic hydrocarbons with alternating

single and double bonds. • Aromatic hydrocarbons are arenes based on

benzene.

BENZENE DERIVATIVES• The nomenclature of substituted benzene ring

compounds is less systematic than that of the alkanes, alkenes and alkynes.

• A few mono-substituted compounds are named by using a group name as a prefix to "benzene", as shown by the combined names listed below.

• A majority of these compounds, however, are referred to by singular names that are unique.

• There is no simple alternative to memorization in mastering these names.

BENZENE DERIVATIVES

ARYL GROUP

• aryl group , in chemistry, group of atoms derived from benzene or from a benzene derivative by removing one hydrogen that is bonded to the benzene ring.

• The simplest aryl group is phenyl, C6H5 ; it is derived from benzene.

ALKYL, ALKENYL, ALKYNYL and ARYL GROUPSHydrocarbons Groups after one hydrogen removed

Name of the Group

Formula Name of the Compound

Name of the Group

Formula Name of the Substituent

Alkane CH4 Methane Alkyl CH3 – Methyl

C2H6 Ethane C2H5 – Etihyl

Cyclohexane Cyclohexyl

Alkene CH2 = CH2 Etene Alkenyl CH2 = CH – Ethenyl(Vinyl)

– CH = CH – CH3 1-PropenylCH2 = CH – CH3 Propene

CH2 = CH – CH2 – 2-Propenyl (Allyl)

Alkyne CH CH Ethyne Alkynyl CH C – Ethynyl

CH C – CH3 Propyne CH C – CH2 – Propynyl

Arene Benzene Aryl Phenyl

Toluene Benzyl

Naphtaline naphthyl

CH3CH2

FORMATION OF ALKANES AND ARENES

• Alkyl, Alkenyl, Alkynyl and Aryl groups are not stable enough to exist as alone.• Their tendency is to join other groups and this bonding tendency is the basis of synthetic organic chemistry.• When alkyl groups join with each other alkanes will form:

CH3-CH3 CH3CH2-CH2CH3 CH3CH2- CH2CH2CH3

Ethane Butane Pentane

• When alkyl groups joined to aryl groups arenes will form. When we are naming arenes (aromatic hydrocarbons) first the name of alkyl group is said then the word benzene is added:

Methylbenzene ( Toluene ) Ethylbenzene

CH3C2H5

FORMATION OF POLYCYCLIC ARENES

• When aryl groups join to each other polycyclic arenes (polycyclic aromatic hydrocarbons) will form.These compounds are named by using their common names.

AnthraceneNaphtaline

FORMATION OF ALKENES • When alkyl groups join to alkenyl groups alkenes will form. 2-

propenyl (CH2 = CH – CH2 -) and methyl ( CH3-) groups join 1- butene will form:

CH2 = CH – CH2 – CH3

• When we are naming alkenes according to IUPAC (Systematic Naming) rules number the carbons in the chain so that the double bond would be between the carbons with the lowest designated number.

1 2 3 4 CH2 = CH – CH2 – CH3

• When writing the name of the compound:

1. first the lower number of the carbon atom which makes the double bond is written then

2. a hyphene (-) is drawn and 3. finally the name of the alkene corresponding to the parent

chain( the longest continuous chain of carbons that have the double bond) is written.

4. 1 2 3 4 1 2 3 4 CH2 = CH – CH2 – CH3 CH3- CH=CH - CH3

1- butene 2- butene

NAMING ALKENES

NAMING ALKENES

FORMATION OF ALKYNES • When alkyl groups join to alkynyl groups alkynes will

form.

• For example: ethyl (C2H5-) and propynyl (CH C – CH2 -) groups joined to each other 1-pentyne will form:

1 2 3 4 5

CH C – CH2 – CH2 – CH3

NAMING ALKYNES1. Identify the longest continuous chain of carbon atoms that

contains the carbon-carbon triple bond. The parent name of the alkyne comes from the IUPAC name for the alkane of the same number of carbon atoms, except the - ane ending is changed to - yne to signify the presence of a triple bond. Thus, if the longest continuous chain of carbon atoms containing a triple bond has five atoms, the compound is pentyne.

2. Number the carbon atoms of the longest continuous chain, starting at the end closest to the triple bond. Thus,

is numbered from right to left, placing the triple bond between the second and third carbon atoms of the chain. (Numbering the chain from left to right incorrectly places the triple bond between the third and fourth carbons of the chain.)

Naming Alkynes3. The position of the triple bond is indicated by placing

the lower of the pair of numbers assigned to the triple-bonded carbon atoms in front of the name of the alkyne. Thus the compound shown in rule 2 is 2-pentyne.

4. The location and name of any substituent atom or group is indicated. For example, the compound

is 5-chloro-2-hexyne.

ALKYL HALIDES AND ALCOHOLS• When halogens and alkyl groups join to each

other alkyl halides will form.• In the functional groups table - I we can see

ethyl bromide as an example of an alkyl halide.• Similarly when hydroxide and alkyl groups join

to each other alcohols will form.• In the functional groups table - I we can see

propyl alcohol or propanol (C3H7 - OH) as a combination of a propyl (C3H7 -) and hydroxide

(- OH) groups.When we are naming alcohols in common naming syste,first the name of alkyl group is written than the family name alcohol is added.

FUNCTIONAL GROUPS

• Alkyl groups can also join with halogens and other atoms or atom groups to form organic ompounds other than hydrocarbons.

• Groups that are joined to alkyl grous which have tendency to react chemically are called Functional Groups.

• Functional groups will be represented in a table in the next two slides. The R, R',R1,R2,R3 and R4

written as bold represent different alkyl groups.• But R not written as bold are generally represent

alkyl groups and in some special cases it may be hydrogen,H.

Functional

Groups in

Compounds

Family Name

General Formula Formula of the Compund as an

Example

Name of the Compound

R Alkane R H or R R CH3 – CH3 Ethene

C = C Alkene R2 R1 HC = CH R3 R4 CH3CH2CH = CHCH2CH3 3-hexene

C C Alkyne R1 C C R2 C2H5 – C C – CH3 2-pentyne

Arene Methyl benzene

(Toluene)

X(-F, -Cl, Br, -I)

Alkyl

Halide

R – X C2H5 – Br Ethyl bromide

OH Alcohol R – OH C3H7 – OH Propyl alcohol

(propanol)

O Ether R – O – R' CH3 – O – CH3 Dimethyl ether

Aldehyde Acetaldehyde

Ketone Propanone

(dimethyl ketone)

R CH3

O

C H

O

C HR

O

C HCH3

O

CO

C R'R

O

CCH3 CH3

NAMES AND FORMULAS OF COMMON FUNCTIONAL GROUPS AND DERIVED COMPOUNDS - I

Functional Groups in

Compounds

Family Name General Formula Formula of the Compund as an

Example

Name of the Compound

carboxylic acid Propanoik acid

Amine Propylamine

Nitro alkane Nitromethane

C N Nitrile R C N CH3 C N Ethanenitrile

Ester Ethyl ethanoate

Amide acetamide

(Ethanamide)

Acyl halide acetyl chloride

O

C OH

O

C OHR

O

CC2H5 OH

H

N H

H

N HRH

NC3H7 H

O

N OO

N OR

O

NCH3 O

O

CC2H5 OCH3

O

C O

O

C OR R'

O

C N

H

H

O

C NR H

H O

CCH3 N

H

H

O

CCH3 Cl

O

C X

O

C XR

NAMES AND FORMULAS OF COMMON FUNCTIONAL GROUPS AND DERIVED COMPOUNDS - II

FUNCTIONAL GROUPS

FUNCTIONAL GROUPS

LEARNING CHECK1. Draw the stuructural formula and write the

name of the compound made of ethyl(-C2H5) and butenyl(CH2 = CH – CH2 – CH2-) grops.

2. Draw the stuructural formula of 2- pentene.3. Draw the stuructural formula of isobutyl

chloride.4. Write the IUPAC name of the structure:

CH3 – CH2 – C C – C2H5

5. Draw the stuructural formula and then write the name of the compound when the alkyl group 1,1-Dimethylethyl and hydroxyl

group (- OH) join to each other.

CCH3

CH3

CH3

PHYSICAL PROPERTIES OF HETEROATOMIC ORGANIC COMPOUNDS

• Heteroatomic groups like hydroxide

(- OH), formyl(- CHO) and caboxyl(-COOH) can join to alkyl groups.

• The physical properties of these heteroatomic compounds are different than that of hydrocarbons having the same number of carbon atoms.

• Due to changes in intermolecular forces based on mass,volume and polarity changes) physical properties will change.

• Alcohols,aldehydes and carboylic acids have higher melting and boiling points than alkyl halides having the same number of carbon atoms due to addition of hydrogen bonding to dipole-dipole interactions.(Remember hydrogen bonding is stronger interaction than dipole-dipole forces.)

LEARNING CHECK

Name m.p (ºC)

b.p

(ºC)

Butane - 138 - 0.5

Butanol - 88.6 117.7

Etoxyethane

(Dimethyl ether)

- 116 34.6

Butylamine - 51 78

Try to explain the differences in melting and boiling points of the compounds in the given table by comparing their intermolecular forces.

PHYSICAL PROPERTIES OF HETEROATOMIC ORGANIC COMPOUNDS

• When heteroatomic groups like hydroxide (- OH), and caboxyl (- COOH) join to alkyl groups solubility

in water will increase since these hydrophilic groups are polar.

Hydrofobic group Hydrophilic group CH3- CH2- CH2 - OH propopyl alcohol Hydrofobic group Hydrophilic group CH3- CH2- CH2 - COOH butanoic acid

• On the other hand hydrocarbons having the same number of carbon atoms with alcohols and carboxylic acids do not dissolve in water since hydrophobes are nonpolar molecules.

CHEMICAL PROPERTIES OF HETEROATOMIC ORGANIC COMPOUNDS

• When heteroatoms are joined to alkyl groups chemical reactivity will be greater than the hydrocarbons having the same number of carbon atoms.

• Saturated hydrocabons(Alkanes) can only give substitution and combustion reactions.

• Alkenes and Alkynes are more reactive than alkanes due to existance of pi bonding.So they can also give addition reactions.

• Heteroatomic organic compounds can give other types of reactions due to polar character of heteroatomic part.

CHEMICAL PROPERTIES OF HETEROATOMIC ORGANIC COMPOUNDS

• Funcional groups can be cations and anions in chemical reactions.

• Acetyl group in the compound H3C – CO – Cl act as a cation since acetyl chloride molecule is polar.

• Cl is partial negative and C is partial positive.

• In the compound Li – CH3 methyl group act as an anion,since methyl lithium molecule is polar.

• CH3 is partial negative and Li is partial positive.

Li+ + CH3- LiCH3

Lithium Methyl Methyl lithium cation anion

O

C+CH3 Cl

Acetyl cation

Chlorine

anion

O

CCH3 Cl

Acetyl chloride

CHEMICAL PROPERTIES OF HETEROATOMIC ORGANIC COMPOUNDS

• In the polar compound Methyl fluoride (Fluoromethane) CH3F methyl group act as a cation and fluorine act as an anion.

CH3+ + F- CH3F

Methyl Fluorine Methyl fluoride cation anion

NAMING OF DIOLS AND TRIOLS• Diols, hydroxyaldehydes ,

hydroxyketones,dicarbonyls,hydroxyacids,ketoacids and dicarboxylic acids are the examples of organic compunds having more than one functional groups.

• Diols (glycols) have two hydroxide (-OH) groups but triols (glycerine) have three hydroxide groups.

• When naming these compounds the longest continuous chain having hydroxide groups is chosen and numbering should start from the end closer to hydroxide group.

• After writing the numbers of carbon atoms bonded to hydroxide groups a hyphen is drawn and then the name of the hydrocarbon is written according to the number of carbon atoms in the longest chain.

• Finally the word diol or triol is added if the molecule has two or three hydroxide groups respectively.

CH2OH2

1

1,2-Ethanediol(Glycol)

CH2OH

CH2OH3

2

1,2,3-Propanetriol(Glycerine)

CHOH

CH2OH1

NAMING OF HYDROXYALDEHYDES AND HYDROXYKETONES

• Hdroxyaldehdes and hdroxyketones have both hydroxide (- OH) and carbonyl( C=O ) groups.

• When naming these compunds the carbon atom having the double bonded should be located to the lowest possible number.

3-Hydroxybutanal

CHCH3

OH1 2

CH2

3C

O

H4

4-Hydroxy-4-methyll-pentane-2-on

(Diaceton alcohol)

CCH3

O1 2

CH2

3C OH

4

CH3

CH3

5

NAMING OF DICARBONYL COMPOUNDS• Dicarbonyl compounds are dialdehydes,aldehyde-ketone and

diketones.• When naming these compounds the longest chain is

numbered in such away that the carbonyl group should be located to the lowest possible number.

• After writing the numbers of carbon atoms bonded to oxygen atoms a hyphen is drawn and then the name of the hydrocarbon is written according to the number of carbon atoms in the longest chain.

• Finally do not forget to add the suffixes - dione,- trione,- dial and – trial depending on the the type and number of functional groups.

• –al suffix will be used for aldehyde and -one suffix will be used for ketone.

2,4-PentandioneAcetylacetone

CCH3

O1 2

CH2

3C CH3

4O

5

1,4-ButanedialSuccinindialdehy

de

CH

O31

CH2

2C H

4O

CH2

NAMING OF KETOACIDS

• Ketoacids are the carbonyl group containing carboxylic acids.

• When naming these compounds the longest chain is numbered in such a way that the carboxylic acid should be located to the lowest possible number.

• Carbonyl group is defined by oxo- (=O) prefix.

• Write the name of the hydrocarbon according to the number of carbon atoms in the longest chain and then add the suffix –oic acid.

O

CCH3 COOH

2-Oxopropanoic acidPirüvik asi

4O

CCH3 CH2

3-Oxobutanoic acidAcetoacetic acid

COOH3 2 1

NAMING OF HYDROXYACIDS

• Hydroxy acids are the compounds having both hydroxyl(-OH) and carboxyl (-COOH) groups.

• When naming these compounds the longest chain is numbered in such a way that the carboxylic acid should be located to the lowest possible number.

• After writing the number of carbon atom which is bonded to hydroxyl group a hyphene is added.

• Then hydroxy prefix is written, the name of the hydrocarbon according to the number of carbon atoms in the longest chain and the suffix –oic acid is added.

COOH

2-Hydroxypropanoic acidLactic acid

C OHH

C HH

H

COOH

2,3-Dihydroxyibutanedioic acid

Tartaric acid

C OHH

C HOH

COOH

COOH

Hydroxybutanedioic acidMalic acid

C OHH

CH2

COOH

NAMING OF DICARBOXYLICACIDS

• Dicarboxylic acids are the compounds having two carboxyl groups in their molecules.

• When naming them, write the name of the hydrocarbon according to the number of carbon atoms in the longest chain and then add the suffix –dioic acid.

Ethanedioic acid

Oxalic acid

COH

O

C

O

OHButanedioic

acidSuccinic acid

COH

O

C

O

OHCH2 CH2

CONDENSED STRUCTURAL FORMULAS

• Chemical structures may be written in more compact forms, particularly when showing organic molecules.

• In condensed structural formulas, many or even all of the covalent bonds may be left out, with subscripts indicating the number of identical groups attached to a particular atom.

• Two varieties of condensed structural formula, both showing butane:

SKELETAL ( BOND-LINE ) FORMULA

• Another shorthand structural diagram is the skeletal formula (also known as a bond-line formula or carbon skeleton diagram).

• In skeletal formulae, carbon atoms are not signified by the symbol C but by the vertices of the lines.

• Hydrogen atoms bonded to carbon are not shown — they can be inferred by counting the number of bonds to a particular carbon atom — each carbon is assumed to have four bonds in total, so any bonds not shown are, by implication, to hydrogen atoms.

• A skeletal diagram of butane:

SKELETAL ( BOND-LINE ) FORMULA

• For example, in the image below, the skeletal formula of hexane is shown.

• The carbon atom labelled C1 has only one bond shown to it, so there must also be three hydrogens bonded to it, in order to make its total number of bonds four.

• The carbon atom labelled C3 has two bonds to other carbons and is therefore bonded to two hydrogen atoms as well.

BALL-AND-STICK MODEL

• A ball-and-stick model of the actual molecular structure of hexane, as determined by X-ray crystallography, is shown for comparison, in which carbon atoms are depicted as black balls and hydrogen atoms as white ones.

COMPARISON OF DIFFERENT MODELS

• Shown below for comparison are a ball-and-stick model of the actual three-dimensional structure of the ethanol molecule in the gas phase (determined by microwave spectroscopy, left), the Lewis structure (centre) and the skeletal formula (right).

Bazı organik bileşiklerin iskelet (çizgi-bağ) formülleri

Name of the compound

Molecular formula

Stuructural Formula

Bond-Line Formulas

Isohexane C6H14

Ethyl acetate

(Ethyl ethanoate)

CH3CO2C2CH5

Acetophenone C6H6COCH3

Neopentane C5H12

CH3

CH

CH2

CH2

CH3

CH3

CH3 O

CH2

CH3

C

O

C

CH3

O

CH3CH3

C

CH3CH3

O

O

O

BOND-LINE FORMULAS OF SOME ORGANIC COMPOUNDS

LEARNING CHECK

1. Name the following compounds represented by the bond- line formulas:

2. Draw the stuructural formulas of the following compounds and then write their bond-line formulas:

a) ethyl ethanoate

b) 1- aminobutane

c) 2- chloro- 4 - methylheptane

OH

REFERENCES• http://chemed.chem.purdue.edu/genchem/topicreview/bp/1organic/1org_frame.h

tml• http://en.wikipedia.org/wiki/Hydrocarbon• http://www.elmhurst.edu/~chm/vchembook/500hydrocarbons.html• http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/nomen1.htm• http://chemed.chem.purdue.edu/genchem/topicreview/bp/2organic/function.html• http://en.wikipedia.org/wiki/Functional_group#Table_of_common_functional_gro

ups• http://en.wikibooks.org/wiki/Organic_Chemistry/Overview_of_Functional_Groups• http://www.tamug.edu/mars/chem227/functgrtbl.htm• http://masterorganicchemistry.com/2011/02/14/table-of-functional-group-prioritie

s-for-nomenclature/• http://www.chemistry-drills.com/functional-groups.php?q=simple• http://www.ausetute.com.au/fungroup.html• http://www.ausetute.com.au/usehydrc.html• http://en.wikipedia.org/wiki/Aromatic_hydrocarbon• http://en.wikipedia.org/wiki/Simple_aromatic_ring• http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/nomen1.htm

REFERENCES• http://en.wikipedia.org/wiki/Lewis_structure• http://en.wikipedia.org/wiki/Skeletal_formula• http://en.wikipedia.org/wiki/IUPAC_nomenclature_of_organic_chemistry• http://www.physchem.co.za/OB12-mat/organic2.htm• http://dl.clackamas.edu/ch106-01/alkyl1.htm• http://www.personal.psu.edu/the1/nomencl.htm• http://www.personal.psu.edu/faculty/t/h/the1/chem/Nomenclature/index.ht

ml#12• http://www.vanderbilt.edu/AnS/Chemistry/Rizzo/chem220a/alkenes.pdf• http://www.cliffsnotes.com/study_guide/Alkynes-

Nomenclature.topicArticleId-22667,articleId-22630.html• http://www.angelo.edu/faculty/kboudrea/organic/IUPAC_Handout.pdf• http://www.angelfire.com/bc2/OrgChem/alkenes.html• http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/nomen1.htm• http://en.wikipedia.org/wiki/Functional_group