2.2 - nomenelature and isomerism in organic compounds

Define homologous series

compounds with same general formula, similar chemical properties, graduation in physical properties and differ by CH2 group

Define functional group

reactive group within compound

Define structural isomers

molecules with same molecular formula but different structural formula

Define geometrical isomers

molecules with same structural formula but different arrangement of atoms due to one or more C=C bond

Molecular formula - C4H8

C4H8

Empirical formula - C4H8

CH2

Condensed formula - C4H8

CH3CH2CH2CH3

Displayed formula

Fully displayed individual elements with bonds showing

Structural formula

Condensed elements with bonds showing

Skeletal formula

bonds with C not displayed

How do homologous series differ?

according to group of atoms attached to carbon chain (function groups)

Priority of functional groups in increasing priority

carboxylic acid, nitrile, aldehyde, ketone, alcohol, amine, alkene, alkane, haloalkane

What happens to name if more than one functional group present?

di/tri/tetra added to end of name

How to find main group if molecule has over 1 functional group?

group of highest priority is main group and lower are substituents

What are IUPAC names?

systemic names

What are systemic names?

IUPAC names

First 6 alkanes prefixes

meth, eth, prop, but, pent, hex

How to name alkanes

C no. alkyl groups on first, then alkyl groups, then name of longest C chain

How to order substituent groups

alphabetical order

How are numbers and letters separated?

hyphen

How are numbers separated?

commas

How to name halogenoalkanes

same way as hydrocarbons, treating halogens as side chains(fluoro, bromo, chloro), use ane

How to name alkenes

same as hydrocarbons but double bond position stated, ene replaced ane

How to name alcohols

same as alkenes but name C alcohol group on, ol replaces ene

Three types of structural isomerism

chain isomers, position isomers, functional isomer

Chain isomerism

molecules with different arrangement of atoms on C chain

Positional isomerism

molecules with same functional group in different positions in same C skeleton

Two types of stereoisomerism

geometrical isomers, optical isomers

Geometrical isomerism

free rotation is property of single bonds but no rotation around double bond, giving geometric isomers, alkenes have geometrical isomerism if both C atoms have different atoms/groups of atoms attached

What does E mean?

opposite

What does Z mean?

together

What is an E isomer?

priority groups opposite to eachother

What is a Z isomer?

priority groups same side to eachother

How is E/Z determined?

CIP priority rules

CIP priority rule 1

higher atomic number of atom = higher priority

COP priority 2

if two atoms same, apply Rule 1 to next atom/sequence of atoms in substituent