Zusammenfassung der Ressource
Mechanisms
- Free Radical Substitution
- Initiation
- UV light or +300C causes the covalent bond to break (fission).
- Hetrolytic Fission is unequal splitting of the
electrons due to 2 different elements ( EG; H-Cl )
- Homolytic Fission is equal splitting of the
electrons due to 2 identical elements ( EG: Cl-Cl )
- This forms 2 Radicals
- After initiation the reaction doesn't require
any more energy input
- Propagation
- In this case, the Chlorine Radical reacts with the methane,
- Forming HCl and a Methyl Radical
- Which then splits another Chlorine Molecule into 2 Radicals
- Termination
- This is when 2 Radicals bond to form a compound or molecule only
- No new radicals are formed
- This reaction can produce Haloalkanes
- Elimination
- Conditions
needed:
- High Temperatures
- Concentrated Hydroxide Ions
- Ethanol as the
solvent
- This reaction causes
Haloalkanes to turn into a
Water molecule, a Halogen Ion and an
Alkene
- Electrophilic Addition
- Can change Alkenes to Haloalkanes
- An Electrophile is a
species than can
accept a pair of
electrons
- The Pi bond is broken when the electrophile gets close to it
- A Di-Halogen Alkane is formed
is a Halogen molecule is the
electrophile
- Nucleophilic Substitution
- A Nucleophile is a species that is
attracted to an electron defiecient
centre, where it donates a pair of
electrons to form a dative bond
- Conditions needed:
- warm temperatures
- Aqueous
Nucleophile ions
- Dilute Solutions
- Hydroxide ions and
Haloalkanes form
Alcohols
- Cyanide Ions and
Haloalkanes form Nitrilles
- Excess Ammonia and
Haloalkanes form
Amines