6.2 nitrogen compounds Flashcards
what are amines
compounds derived from ammonia that have a H replaced with an alkyl group
known for pungent smell
how do you name amines
use suffix -amine after carbon chain
use prefix -amino for branched/ more complex molecules
for secondary or tertiary amines each group from amine group is named separately. the longest chain has the suffix -amine
how are amines bases
lone pair on the N atom is able to form a dative bond with a proton acceptor
what are amides
compounds with an amine group directly bonded with a carbonyl group.
They can be classified as either:
Primary R-CONH2
Secondary R-CONH-R’
secondary amide formation
[ see flashcard for mechanism]
Secondary amides can be formed by the reaction of amines with carboxylic acids via a condensation reaction.
Acid anhydrides or acyl chlorides could also be used.
how are amines hydrolysed
The secondary amide group can be hydrolysed under:
Acidic conditions to form a carboxylic acid and an ammonium salt.
As the amine formed will react with the acid.
Alkaline conditions to form a carboxylate salt and an amine.
As the carboxylic acid formed will react with the alkali.
what are amino acids
alpha amino acids contain both an amine group and a carboxylic acid that is separated by a carbon atom
has the general formula RCH(NH2)COOH
R groups can be an alkyl, -OH, -SH, -COOH, -NH2 ect
[see physical flashcard for structure]
how to name amino acids
the carboxylic acid takes priority so the amino acid will always be in position 2
e.g. 2-aminobutanoic acid
what are zwitterions
the carboxyl group is able to donate a proton to amine groups, resulting in an internal salt, known as a zwitterion
have no overall charge as the charges cancel out
form at an isoelectric point- pH level is unique to each amino acid due to the attached R group
amino acid reacts as an acid with a base
the carboxylic acid group can react with a base to form a salt, and with an alcohol to form an ester
[see physical flashcard for mechanism]
what are amino acid reacts as a base
the amine group is a base and so can react with an acid, such as HCl to produce a salt
[see physical flashcard for mechanism]
the amine group can also behave as a nucleophile and can react with slightly positive carbons bonded to slightly negative X
[see physical flashcard for mechanism]
what is the formation of peptide bonds in amino acids
there are numerous other reactions that depend on both functional groups, the most important being the formation of peptide links
[see physical flashcard for mechanism]
a dipeptide bond contains a dipeptide link -CONH and 2 side chains (R groups)
dipeptides can react further with additional amino acids
what is condensation polymerisation
where 2 monomers link together to form a long chain (polymer) and there is a loss of a small molecule such as water or hydrochloric acid
there are 2 main types- polyesters and polyamides
what is terrylene (PET)
an important common ester used in synthetic fibres and containers for food and beverages
made by reacting benzen-1,4-dicarboxylic acid and ethane-1,2-diol
has a regular approximately linear structure
polymer chains pack closely together
induced dipole-dipole
what are polyesters
made of carboxylic acids and alcohols
could also use hydrocarboxylic acids which contain both a carboxylic acid and an alcohol
