3.2 Synthesis Flashcards
Fission
Process of bond breaking
Homolytic Fission (3 points)
- Results in the formation of two neutral radicals
- Occurs when each atom retains one electron from the sigma covalent bond and the bond breaks evenly
- Normally occurs when non-polar covalent bonds are broken
Heterolytic Fission (3 points)
- Results in the formation of two oppositely charged ions
- Occurs when one atom retains both electrons from the sigma covalent bond and the bond breaks unevenly
- Normally occurs when polar covalent bonds are broken
Single-Headed Arrow
Movement of a single electron
Double-Headed Arrow
Movement of an electron pair
Homolytic fission in terms of arrows
Two single-headed arrows starting at the middle of a covalent bond
Heterolytic fission in terms of arrows
One double-headed arrow starting at the middle of a covalent bond
Nucleophiles (3 points)
- Negatively charged ions or neutral molecules that are electron rich
- Attracted towards atoms with a partial or full positive charge
- Able to donate an electron pair to form a new covalent bond
Examples of Nucleophiles
Cl-, Br-, OH-, CN-, NH3 and H2O
Electrophiles (3 points)
- Positively charged ions or neutral molecules that are electron deficient
- Attracted towards atoms with a partial or full negative charge
- Able to accept an electron pair to form a new covalent bond
Examples of Electrophiles
H+, NO2+, SO3
Haloalkanes
Substituted alkanes in which one or more of the hydrogen atoms is replaced with a halogen atom
Monohaloalkanes (2 points)
- Contain one halogen atom
- Can be classified as primary, secondary or tertiary with number of alkyl groups
Alcohols
Substituted alkanes in which one or more of the hydrogen atoms is replaced with a hydroxyl functional group
Ethers
Substituted alkanes in which a hydrogen atom is replaced with an alkoxy functional group, -OR
SN1 Reactions
Nucleophilic substitution reaction with one species in the rate determining step and occurs in a minimum of two steps via a trigonal planar carbocation intermediate
SN2 Reactions
Nucleophilic substitution reaction with two species in the rate determining step and occurs in a single step via a single five-centred, trigonal bipyramidal transition state
Substitution
Atoms are added to a molecule by replacing atoms already present
Addition
Joining two or more molecules together to form a larger molecule
Elimination
When a small group of atoms breaks away from a larger molecule with the release of a small molecule
Condensation
The joining of molecules with the release of water as a product
Hydrolysis
The breakdown of a molecule by water
Neutralisation
When an acid and a base react to form water
Markovnikov’s Rule
States that when a hydrogen halide or water is added to an unsymmetrical alkene, the hydrogen atom becomes attached to the carbon with the most hydrogen atoms attached to it already.
