3.3.1 Introduction to organic chemistry What can you remember from GCSE? 1. Organic chemistry is all about the Chemistry of compounds containing which element? How many covalent bonds do atoms of this element normally form? 2. Draw the displayed formula and write the formula of the following alkanes: methane, ethane, propane, butane. 3. What is the general formula of alkanes? 4. Are alkanes described as saturated or unsaturated? Explain your answer. 5. Draw the displayed formula and write the formula of the following alkenes: ethene and propene. 6. What is the general formula of alkenes? 7. Are alkenes described as saturated or unsaturated? Explain your answer.

Organic nomenclature (ie naming organic compounds)

We are learning about... naming organic compounds IUPAC rules We shall do this by... noticing links between structures and names testing and modifying ideas collaborating and sharing ideas

The challenge You have a sheet with the structure and names of a variety of organic compounds You may assume that these are the correct names! You need to devise a set of rules (ie bullet point steps) that would enable someone else to work out the name of the compound if they were given only the structure

For example: “ count the number of C atoms” may be one “rule”, or part of one, but would then need a follow-up instruction.

Alkanes, with and without side chains...

More complex compounds... There are several follow-up sheets, with more structures and names How do your rules need to change to fit the new compounds ? –what new rules do you need? –do you need to modify any of the existing ones ? –do any need to be ditched completely ?!

More about side chains...

What have you got so far?

Moving on from alkanes... What happens when a double bond is introduced?

Alkenes, with and without side chains...

What extra rules were needed? Did any need to change?

What about molecules with other types of atoms attached? In particular, halogen atoms... (There will be others later on!)

Haloalkanes...

What extra rules were needed this time? Did any need to change?

And now mixing them all together...

Mixed functional groups...

What do we end up with as a final list of rules?

The IUPAC rules find longest continuous chain of C meth-, eth-, prop- etc use cyclo- if there is a ring any C=C? If yes: -en(e) ; if no: -an(e) number the position of the C=C from one end of the C chain, giving it the lowest number possible any other side chains and/or functional groups? arrange prefixes alphabetically more than one of the same group? use di-, tri-, tetra- etc give the position of EVERY group numbering from one end of the C chain so that the lowest numbers possible are used (if there was a C=C, use this numbering

officially, numbers should be separated from letters by “–” ; two numbers should be separated by “,” in most cases, there should not be any spaces in the name

Some definitions There are a number of definitions linked to organic chemistry that you need to know Some you will have come across before, some are new Sort the information provided to give you the definitions and some examples then LEARN THEM!

Molecular Empirical Structural Skeletal Displayed simplest ratio of... actual number of... shows connectivity no C-H bonds or C/H atom labels shown, just C–C bond and bonds to/labels for other atoms all bonds shown Homologous series share general formula; same functional group; similar chemical properties; gradual trend in physical porperties Functional group atom(s) responsible for chemical properties