Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Title: F324 A2 chemistry
Description: These notes cover all aspects of the module F324, the only thing required is to fill in the boxes with diagrams and add curly arrows to the mechanisms.
Description: These notes cover all aspects of the module F324, the only thing required is to fill in the boxes with diagrams and add curly arrows to the mechanisms.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
F324 notes
Arenes
Structure and bonding in benzene:
Each Carbon makes 3 -bonds: 1x C-h and 2x
c-c
All bond lengths between carbons are equal
P-orbitals on adjacent carbons overlap
sideways to form a π-system
π-system had 6 e- delocalised across all
carbons in the ring
π-system e- density above and below the ring
...
H2SO 4
+ H2O
≤ 10°
(Conc
...
3°
[H] = reducing agent NaBH4 (2 per reduction)
Wet tests for carbonyl compounds:
1) H+/Cr2O72
Observation: orange to green
2) Tollen’s reagent
Conditions: Tollen’s + heat + ethanol (solvent)
Observation: Silver mirror
3) 2,4 – DNPH
Orange precipitate with pure carbonyls – aldehyde and ketone, re-crystallise and find MP of
crystals and compare to a data bank of crystals
...
Mechanism in words:
1) Hydride ion nucleophilically attacks the C to make a dative covalent bond
2) The C=O π-bond break heterolytically towards O to generate an oxyanion (O -)
3) 1 lone pair from O- forms a dative covalent bon to H from water
Esterification
Esters are used for perfumes/flavourings
...
C : No
...
If there is H directly next to N, O or
F within a molecule, H bonding will take
place between molecules
...
Amino acids:
α amino acids – amine and carboxylic acid attached to same
carbon
...
F324 notes
Above the isoelectric point: everything that can be protonated will be deprotonated
...
Below
+
At
0
Above
-
Formation of polypeptides:
Synthesis:
NH2
NH2
Aromatic amine
Aliphatic amine
Preparation of aliphatic amine:
Halogenoalkane + ammonia
Mechanism:
aliphatic amine
NH2
aliphatic amine
F324 notes
Condtions:
Excess of ammonia – minimises reaction with product
Ethanolic ammonia – prevents formation of an alcohol
Preparation of an aromatic amine:
NO2
NH2
+
6 [H]
+
Sn/Conc
...
Optical isomerism
Carbon attached to 4 different groups
causes chirality
...
1x chiral carbon = 2 versions
2x chiral carbon = 4 versions
Problems with chirality:
For the patient –
One isomer may have harmful side effects
One isomer may be biologically inactive; increased dose required (liver)
F324 notes
For the pharmaceutical company –
One isomer may be biologically inactive; increased dose required (money)
Chiral seperation is expenssive and difficult
Methods to prevent chirality:
During synthesis –
Use naturally occuring enzyme
Chiral pool synthesis
After synthesis –
Chiral seperation
Polyesters and polyamides
Polyesters:
Method 1:
Method 2:
Polyamides:
Method 1:
F324 notes
Method 2:
Hydrolysis of polymers:
Polyester:
Acid:
Alkali
Polyamide:
Acid:
Alkali
Analysis
Chromatography:
Seperates components in a mixture between a stationary phase and a mobile phase
...
Adsorbtion is the process where a solid holds gas or liquid on the surface of a solid
...
RF value: ratio of distance migrated by a substance compared with solvent front
...
Highy temperatures so unsuitable for biological molecules
...
Limitations of gas chromatogtaphy:
Similar substances have similar retnetion time
If unknown substance, no retention time recorded
GC may be combined with mass spectroscopy to make it more useful – can be used in forensic
investigations
...
13C
spectrum tells you:
Number of different carbon environments
Types of carbon environments
High resolution 1H spectrum tells you:
Number of proton environments
Type of proton environment
Relative number of protons in different environments
Number of adjacent protons
Sometimes you see a peak at 0, tetramethylsilane (TMC) is assinged this number and used to
calibrate the scale
...
All normal solvents have protons and would produce their own peaks deuterated solvents e
...
CDCl 3
is used – these do not produce a signal due to 2H
...
When added, N-H or O-H groups siganl disappears
as D replaces H; these protons are said to be labile
...
5 scenarios for signal splitting:
1
...
Protons on adjacent carbons on one side only simply follows n+1 rule
3
...
Protons on adjacent carbons on more than one side with unequal amount of protons forms
a mulitplet
...
OH and NH (SH) do not get involved in splitting
Title: F324 A2 chemistry
Description: These notes cover all aspects of the module F324, the only thing required is to fill in the boxes with diagrams and add curly arrows to the mechanisms.
Description: These notes cover all aspects of the module F324, the only thing required is to fill in the boxes with diagrams and add curly arrows to the mechanisms.