Chapter 27 - Amines, Amino Acids and Polymers Flashcards
Amines, Amino acids, amides, and polymers, Condensation polymers.
what is an amine?
amines are compounds derived from ammonia where one or more of the hydrogens in ammonia NH3 are replaced by a carbon ring or chain. eg NH2, NH1 or just N
What is the difference between an aliphatic amine and an aromatic amine?
Aliphatic - nitrogen is attached to at least one straight or branched carbon chain
Aromatic - nitrogen is attached to an aromatic ring
what does a primary secondary and tertiary amine look like?
how do you name primary amines? secondary and tertiary amines?
primary amines are named by adding the suffix amine to the name of the alkyl chain e.g ethylamine
secondary and tertiary amines are named if they contain the same alkyl group by adding the prefix ‘di’ or ‘tri’ e.g (CH3)2NH is dimethylamine. When 2 or more different groups are on the amine group the amine
What do amines often behave as?
Amines often act as Bases accepting a H+ atom
How do amines behave as bases?
Nitrogen donates electron pair to H+
amine + acids = ?
For the formation of aliphatic primary amines, what is reacted together in the two steps?
what is the purpose of ethanol in formation of aliphatic amines?
ethanol is a solvent, used to prevent substitution of haloalkane by water to produce alcohols.
In primary aliphatic amine formation, what is in excess and why?
Ammonia is in excess as it Prevents product from reacting with more of the haloalkane
In aliphatic primary amine formation, what is the purpose of ethanol?
ethanol acts as a Solvent
Prevents substitution of haloalkane by water to produce alcohols
how are aromatic amines produced?
phenylamine is produced by the reduction of nitrobenzene when its heated under reflux with tin and HCl (reducing agents) to form an ammonium salt, phenylammonium chloride. which is then reacted with excess NaOH.
What are the two steps of forming a secondary amine and tertiary amine from a primary amine?
to form a secondary amine…
Primary amine + CH3Br and ethanol as solvent
then
Salt product + NaOH forms secondary amine
How is phenylamine made from nitrobenzene?
phenylamine is made from nitrobenzene
when it is heated under reflux with tin and HCl to form ammonium salt
Ammonium salt reacted with NaOH to produce phenylamine
What do tin and HCl act as in formation of phenylamine from nitrobenzene?
tin and HCL act as a Reducing agent
What is the general structure of an alpha amino acid?
An a amino acid has the NH2 and COOH groups attacked the same a-carbon. Different a-amino acids have different side chains, R, attached to the same a-carbon atom. general formula of RCH(NH2)COOH
amino acid + aqueous alkali = ?
What are amino acids contain?
An Amino acid has both an Amine group (NH2) and a Carboxyl acid group (COOH) group. hence amino acid :)
amino acids + acid = ?
amino acid + aqueous base=?
heating an Amino acid + alcohol = ?
what is esterification of amino acids with alcohols?
heat with alcohol + amino acid
in presence of conc H2SO4 and NaOH
What is the purpose of NaOH in amino acid esterification?
Free the base from the HSO4- salt of H2N- group
what is a chiral carbon?
A chiral carbon is attached to four different atoms or groups of atoms
Amino acids are amphoteric, what does this mean?
Have acidic and basic properties
How can amino acids act as a base and an acid?
NH2 group acts as a base
COOH group acts as an acid
what are amides?
How are amides formed?
Reaction of acyl chloride with ammonia/amines
what are stereoisomers?
stereoisomers are compounds with the same structural formula but different arrangement of atoms of space. There are two types of stereoisomers: optical and E/Z isomerism.
what is optical isomerism?
optical isomerism is found in molecules that contain a carbon atom with a chiral centre.
1) a chiral atom is attached to four different atoms or groups of atoms
2) the four groups attached to the chiral carbon are arranged in space as two non superimposable mirror images called optical isomers
3) each chiral carbon atom has one pair of optical isomers
What do optical isomers have in common?
Same physical properties
do a-amino acids contain chiral centers?
excluding glycine all a-amino acids contain a chiral carbon
What do optical isomers do?
Rotate plane-polarised light
how to draw optical isomers?
what are polyesters?
polyesters are monomers joined together by ester linkages
What are the two monomer types that form polyesters?
monomers with Diols (2 hydroxyl groups) or Dicarboxylic acids
How can polyesters be formed from one monomer?
condensation polymerisation is when polyesters are formed by a compound where One end has an alcohol (OH) group and the Other end has carboxyl group (carboxylic acid COOH )
1) An ester linkage forms between the two molecules, together with water byproduct
What is condensation polymerisation?
Joining of monomers with loss of a small molecule, usually water or HCl where two different functional groups are needed
what are polyamides?
in a polyamide, the monomers have been joined together with amide linkages to form the polymer
polyamides can be made from either:
1) one monomer containing both a carboxylic acid and amine group
2) two monomers one containing two carboxylic acid groups and the other containing two amine groups.
How can polyesters be formed from two monomers?
one monomer contains two hydroxyl (OH) groups- a diol
Another monomer contains two carboxylic acid groups
How can polyamides be formed from just one monomer?
Amino acids contain a carboxylic acid and amine group. they form water
What is the common name for polyamides made from two monomers?
Nylon
how can polyamides be made from two monomers? what does an amide bond look like?
polyamides can be made by the reaction of a dicarboxylic acid/ diacyl chloride with a diamine.
hydrolysing polyamides shown?
hydrolysing polyesters shown?
What is required for polyesters and polyamine’s to undergo hydrolysis? what’s the product?
polyesters and polyamides can be broken down by hydrolysis using:
1) hot aqueous acid like HCl (acid hydrolysis) to form a carboxylic acid and an alcohol
2) hot aqueous alkali like NaOH to form a carboxylate salt and an alcohol
What is formed from polyester undergoing acid hydrolysis?
when a polyster undergoes acid hydrolysis it forms a Diol and a Dicarboxylic acid
What is required to undergo base hydrolysis?
Excess NaOH
What is formed from acid hydrolysis of polyamide?
Diammonium salt
Dicarboxylic acid
What is formed from polyester undergoing base hydrolysis?
A Diol
and a Salt of dicarboxylic acid
is formed from polyester undergoing base hydrolysis
What is formed from base/acid hydrolysis of polyamide?
Diamine
Salt of dicarboxylic acid
is formed from base hydrolysis of polyamide
How does addition polymerisation differ from condensation polymerisation with monomers?
Addition - monomer contains C=C bond
Condensation - two monomers with two functional groups or one monomer with two different functional groups
how do you identify the type of polymerisation given the monomers and the monomers from the polymer chains?
How does addition polymerisation differ from condensation polymerisation with backbone?
Addition - backbone of polymer is -C-C- bond
Condensation - polymer back bone contains ester or amide groups
what does a polyamide amide linkage look like?
what does a polyester ester link look like?
