Reactivity of Organic Molecules Flashcards
What does introduction of other elements to hydrocarbons do
Introduces functionality into organic molecules
What does each type of functional group do
Gives a molecule particular physical properties and reactivity
Where do the properties of functional groups come from
The polarity of the carbon-heteroatom bond, and the presence of lone pairs of electrons
What does a group with excess electrons attack
A group deficient in electrons
What are nucleophiles
Nucleus lovers. They are electron pair donors (Lewis bases). They have a lone pair of electrons, bonding pair of electrons, partial or full negative charge
What we nucleophiles attracted to
Positive charge
What are electrophiles
Electron lovers. Electron pair acceptors (Lewis acids). Incomplete octet of electrons, vacant orbital, partial or full positive charge
What are electrophiles attracted to
A negative charge
What react with electrophiles
Nucleophiles
Why do nucleophiles react with electrophiles
The positive and negative charges attract one another
What happens during a reaction of nucleophiles with electrophiles
The electron pair of the nucleophile becomes shared with the electron deficient electrophile
What is the flow of electrons represented by
Curly arrows
What do curly arrows tell us about
The mechanism of the reaction- what is going on when the reactants are being converted to products
Describe resonance
In some cases when echelons ad delocalised the structure drawn does not accurately represent reality. On average each bond is 1.5 with electron density shared equally over the molecule. In reality electrons do not flow from one structure to another but the overall molecule is a weighted average of the two forms. To show this you draw one of the canonical (wrong structures) but use knowledge of chemistry to infer existence of resonance hybrid
What does indicate
Resonance
What does this drawing show
Resonance. The electrons are constantly flowing around the ring. The reality is the average of the two canonical structures
What is a free radical
A species with an unpaired electron
What are free radicals typically formed by
The action of UV light (or other free radicals)
What are the different types of reaction
- ) nucleophilic substitution
- ) nucleophilic addition
- ) electrophilic substitution
- ) electrophilic addition
- ) free radical substitution
- ) elimination
How do you know if the reaction is concerning the nucleophile/ electrophile/ free radical
It depends which reagent we consider the reaction to be on
How do we know if it is an addition reaction
The product contains all of the atoms of both reactions
How do we know if it is a substitution reaction
Part of one reactant is removed during the reaction to allow the two reactants to join
How do we know if it is an elimination reaction
Something is lost for a reagent without gain
Describe the reactivity of hydrocarbons
It is very limited
