Amines Amino Acids And Polymers Chp27 Flashcards
How do amines act as a base?
Amines have a lone pair of electrons that allows them to accept a proton, a dative covalent bond is formed between the lone pair of electrons on the nitrogen and proton.
What is the strength of the amine dependent on?
the availability of the lone pair of electrons in the nitrogen,
higher density= more readily available
Description of making aliphatic amine.
React haloalkane with excess ammonia in ethanol producing a primary amine and ammonium halide.
What is the downside of substitution with Haloalkanes?
The downside is that primary amines still have a lone pair on the nitrogen on the primary amine, so it also acts a nucleophile reacting further to produce secondary, tertiary and quaternary salts too so we have an impure product.
Why is ethanol used as a solvent?
-Ethanol prevents any substitution of haloalkane by H2O to produce alcohols.
-Excess ammonia is used bc it reduces further substitution of amine to form 2* and 3* amines.
What are the steps to making aromatic amines (reducing nitro compounds)
Step 1: Heat nitrobenzene under reflux with conc HCl and tin to form a salt.
Step 2: Salt produced is reacted with an alkali such as NaOH to produce an aromatic amine + water + NaCl
Amides
Derivates of carboxylic acids and have a functional group of -CONH2
Amino acids
- amphoteric (have both acidic and basic properties)
- amino acids have an organic side chain (represented by ‘R’)
- alpha amino acids (except) glycine are chiral molecules
What are chiral molecules?
Molecules which have 4 different groups around a central carbon atom.
Carboxylic acid group reaction with aqueous alkalis
Forms a conjugate base RCH(NH2)COO- which combines with a positive ion to form a salt
Amine group reaction with acids
forms a conjugate acid NH3+ and reacts with negatively charged ion to form a salt
Amino acids reaction with alcohols
Alcohols react with CA group in amino acids to form an ester. Using a strong acid catalyst e.g H2SO4
Optical isomerism
Is a form of Stereoisomerism; non-superimposable images
Enantiomers
Mirror images of each other and are non-superimposable
Condensation polymerisation
Where 2 different monomers with at least two functional groups react together. When they react a link is made, the water is eliminated. (Can react with itself)
