ISOMERISM & AROMATICITY
- Created by: Katy **
- Created on: 10-04-16 13:12
View mindmap
- ISOMERISM & AROMATICITY
- NAMING COMPOUNDS
- carboxylic acid
- R-COOH
- -oic acid
- ketone
- oxo-
- -one
- R-CO-R
- ester
- R-COO-R
- -thyl, -oate
- acid chloride
- -oyl chloride
- R-COCl
- aldehyde
- R-OH
- -al
- alcohol
- hydroxy-
- R-OH
- -ol
- amide
- -amide
- amido-
- R-COCH2
- amine
- amino-
- -amine
- R-NH2
- amino acid
- R-CH(NH2)COOH
- -amino acid
- nitrile
- cyano-
- -nitrile
- R-CN
- benzene
- -benzene
- phenyl-
- C6H6
- phenol
- -ol
- hydroxy-
- C6H5OH
- carboxylic acid
- STEROISOMERISM
- E-Z isomerism
- C=C with different atoms
- one end cannot rotate relative to the other
- E "trans" = on different sides
- Z "cis" = on the same sides
- = same structural formulae but different spacial arrangement
- optical isomerism
- chiral carbon cneter with 4 different groups attached
- mirror images of each other
- enantiomer = reflect & rotate a plane of polarised light in equal & opposite directions (optically active)
- racemic mixture = equimolar mixture of both isomers & has no effect on the plane of polarised light (optically inactive)
- E-Z isomerism
- STRUCTURE OF BENZENE
- flat hexagonal ring of C6H6
- trigonal planar of 120'
- made of single sigma covalent bonds
- unoccupied p-orbitals overlap to form pie bonds
- electrons are delocalised into the pie electron system leading it to be energetically stable
- Against Kekule structure
- all C-C bonds are the same length (0.139nm) which is between single & double bond lengths
- resists addition reactions as it destroys the stable delocalised pie electron system
- delocalised resonance energy is 152 kJmol-1 plus difference
- NITRATION, HALOGENATION & ALKYLATION OF BENZENE
- electrophilic substitution = replacement of ring of hydrogen atoms by an electron deficient group
- in situ = reactant made & reacts as it forms
- nitration of benzene
- reactants
- benzene, nitric acid + sulphuric acid
- products
- nitrobenzene + water
- reactants
- halogenation of benzene
- reactants
- benzene + halogen (bromine)
- catalyst
- anhydrous iron (III) bromide
- halogen carrier
- causes polarisation of Br-Br
- catalytic action
- anhydrous iron (III) bromide
- products
- bromobenzene + HBr
- reactants
- alkylation of benzene
- Friedel-Crafts reaction
- reactants
- benzene + alkyl group (ethyl)
- catalyst
- aluminium chloride
- products
- chlorobenzene + HCl
- ALKALINE HYDROLYSIS OF CHLOROALKANES & CHLOROBENZENE
- nucleophilic substitution
- chloroalkane + NaOH
- reacts easily when refluxed giving alcohol
- reflux = evaporation & condensation are occurring & condensed material is returning to flask where reaction is going on
- cholorobenzene + NaOH
- stronger C-Cl bond due to stable pie electron-ring system of overlapping lone pairs of electrons
- needs more energy to be broken (300'C, increased pressures)
- not economically viable
- needs more energy to be broken (300'C, increased pressures)
- stronger C-Cl bond due to stable pie electron-ring system of overlapping lone pairs of electrons
- NAMING COMPOUNDS
Comments
No comments have yet been made