Structural and skeletal formula

L.O.:

Understand and use the term structural formula.

Understand and use the term skeletal formula.

Draw skeletal formulae for simple molecules containing functional groups.

Draw and interpret the skeletal formula for complex molecules.

Displayed and structural formulae for (a) propane and (b) 1-bromopropane

Displayed formula shows the relative positioning of all the atoms in a molecule and the bonds between them.

A skeletal formula is a simplified organic formula, with hydrogen atoms removed from alkyl chains, leaving just a carbon skeleton and associated functional groups.

decanoic acid

Displayed and skeletal formulae of hexane

Displayed, structural and skeletal formulae for (a) pentane and (b) 3-methylpentane

Aromatic hydrocarbons

Skeletal formula for pent-2-ene

Skeletal formula for butan-2-ol

Skeletal formula for pentanoic acid

Paracetamol

Retinol, vitamin A

Salbutamol

Isomerism

L.O.:

Describe structural isomers, stereoisomers and E/Z isomerism, including cis–trans isomerism.

Determine possible structural formulae and/or stereoisomers from a molecular formula.

Structural isomers of C4H10

Structural isomerism

Where the atoms are arranged together in different ways, with different chemical bonds e.g.

• Branched or unbranched hydrocarbon chain,

• Functional groups coming off of different carbons,

• Different kinds of functional groups (an aldehyde or a ketone for example)

Structural isomers of C3H8O

Stereoisomer are compounds with the same structural formula, but with a different arrangement of the atoms in space.

E and Z isomers of CICH=CHCI

E/Z isomerism is a type of stereoisomerism in which different groups attached to each carbon of a C=C double bond may be arranged differently in space because of the restricted rotation around C=C bond

E and Z isomers of but-2-ene

E and Z isomers

Naming E/Z isomers

Providing that there are two different groups on each side of the double bond, then we put a E or a Z in front of the molecule to denote this

• E = when the two are on different sides• Z = when they are on the same side

Mnemonic: Z when they are on Ze Zame Zide

Naming E/Z isomers 2

Z-1,2-dichloroethene E-1,2-dichloroethene

Naming alkenesThese two molecules look very similar, but are

actually two different stereoisomers

Z-but-2-ene E-but-2-ene

Z or E isomers?Name these molecules:1. 2. 3.

4. 5.

Organic reagents and their reactions

L.O.:Describe the different types of covalent bond

fission – homolytic and heterolytic.

Define the terms: nucleophile; electrophile; radical; addition; and substitution

A radical: an species with an unpaired electron.

A covalent bond can be broken in one of two way:

Homolytic fission: two radical are formed

Heterolytic fission: two different species are formed (cation and anion)

Define:

Nucleophile, electrophile

Substitution reaction

An atom or group is replaced with a different atom or group of atoms.

Addition reaction

Two reactants combine together to make one product.

Elimination reaction

One reactant reacts to form two products.