11.3- ISOMERISM Flashcards
What are isomers?
molecules that have the same molecular formula but whose atoms are arranged differently
What are the two basic types of isomerism in organic chemistry?
structural isomerism
stereoisomerism
What are structural isomers?
have same molecular formula but different structural formulae
What are the three sub-divisions of structural isomers?
positional isomerism
functional group isomerism
chain isomerism
What is positional isomerism?
same functional groups attached to main chain at different points
What is functional group isomerism?
functional groups that are different
What is chain isomerism?
different arrangement of the hydrocarbon chain (i.e. branching)
Why does the existence of isomers make the task of identifying an unknown organic compound more difficult?
as there may be a number of compounds with different structures that all have the same molecular formula
What do you have to use to find out about structure of isomers? (hint- type of method)
use analytical methods
What is stereoisomerism?
where two (or more) compounds have the same structural formula
How do stereoisomers differ?
in arrangement of the bonds in space
What are the two types of stereoisomerism?
E-Z isomerism
optical isomerism
What does E-Z isomerism tell us about?
positions of substituents at either side of a carbon-carbon double bond
What is it called when two substituents are on the same side of the bond? (stereoisomerism)
Z (cis)
What is it called when two substituents are on opposite sides of the bond? (stereoisomerism)
E (trans)
