Intro to Organic chem Flashcards
Saturated organic cmpds
contains only C-C and C-H single bonds
Unsaturated organic cmpds
contains C-C , C-O , C-N double bond
Types of ways to draw compds
- Condensed
- Structural
- Skeletal
- Stereochemical
Types of cmpds characterised by functional groups
- Alkane
- Alkene
- Halogenoalkanes
- Arene (consists of benzene ring)
- Hydroxy compds -OH
- Carbonyl cmpds - Aldehyde -H-C=O /ketone C=O
- Carboxylic acid COOH
- Ester- O-C=O
- Amide -H-N-C=O
- Amine C-NH2
- Phenylamine -benzene-NH2
- Alkyne C triple bond C
- Ether C-O-C
- nitrile C triple bond N
Nomenclature
Prefix-substituents
Parent- longest carbon chain
Suffix- principal functional group
Parent
- Methane
- Ethane
- Propane
- Butane
- Pentane
- Hexane
- Heptane
- Octane….
Suffix
The more times the C is bonded to an O or N the greater the polarity of the functional group. The greater the polarity the more the priority it takes
Prefix
Substituent group fluoro chloro bromo iodo hydroxy nitro amino Alkyl group methyl- CH3 ethyl- CH3CH2 propyl- CH3CH2CH2 Aryl group phenyl
Hybridisation
no.of atomic orbitals mixed = no.of hybrid orbitals formed
hybrid orbitals take part in sigma bond only and unhybridised p orbitals take part in pi bonds
sp3
4 electron regions
hybridised 4 sp3 regions
tetrahedral
sp2
3 electron regions
1 unhybridised 2p orbital
hybridised 3 sp3 regions
trigonal planar
sp
2 electron regions
2 unhybridised 2p orbital
hybridised 2 sp3 regions
linear
Resonance and delocalisation of electron
a molecule/ion exhibits resonance if there are continuous overlap of p orbitals over at least 3 adjacent atoms allowing delocalisation of pi electron
Benzene
All C sp2 hybridised
Due to the continuous overlap of unhybridised 2p orbitals over 6 C atoms allowing for the delocalisation of 6 pi electrons
Due to resonance hybrid structure formation of a partial double bond character can be observed in the bonds between C atoms
Electron flow in a reaction mechanism
movement of a electron pair illustrated by curly arrow originating from electron rich (efficient)region to electron poor region(deficient)
Nucleophiles
Electron rich/efficient species contain pi bonds or lone pair of e available for donation to an electron deficient species
can be neutral molecules with lone pair of e
negatively charged ions
Electrophiles
Electron deficient species accept an electron pair from an electron efficient species
can be atoms which carry partial positive charge
ions that are positively charged
atom that has an empty orbital in its valence shell
Bond fission
- Homolytic
2. Heterolytic
Homolytic fission
When two bonding atoms are of similar electronegativities shared pair of electrons are equally split between the 2 atoms
each atoms acquires one of the bonding pair of electrons forming free radicals
movement of e by two curly half arrows originating from the bond
Free Radical
- Contains an unpaired electron
- very reactive , unpaired electron readily combines with an electron in another atom via a covalent bond
- odd number of electrons
Heterolytic fission
When two bonding atoms of different electronegativities bonding pair of electrons shared unequally between the two atoms.
More electronegative atom acquires both the electrons in the pair. Forming an anion. Less electronegative atom forms a cation
include partial charge in drawing
movement of e by curly full arrow from the bond
Bond formation
Two radicals collide to form an stable product
An electron rich region donates an electron to an electron deficient region
movement of e by curly full arrow from lone pair on more electronegative atom
Types of reaction
CHASERO
Condensation
Two molecules react together to form a larger molecule with the loss of a small molecule (H2O)
Hydrolysis
A large molecule splits into two smaller molecules with the use of a water molecule
acid/alkali used as catalyst
Addition
Occurs when there is unsaturation in reactant molecule
Two species react to form a single product without the elimination of any atom
Substitution
An atom or grp of atoms substituted by another atom/grp of atoms
Elimination
Atoms/grp of atoms are removed to form product that is unsaturated (double bond specifically)
Reduction
1/more O atoms removed from molecule and/or 1/more H is added to molecule
Oxidation
1/more O atoms added to molecule and/or 1/more H is removed from molecule
