Amines, Amino Acids And Polymers

Amines are organic compounds, derived from ammonia, NH3 in which 1 or more H atoms in ammonia have been replaced by C chain or ring

Amines are classified as Primary, secondary or tertiary by the number of alkyl or Aryl groups are attached to N atoms

CH3CH2CH2NH2 Nitrogen atom only has one carbon group attached, a lone pair and 2 H

(C2H5)2NH Nitrogen is attached to 2 alkyl groups and one H and a lone pair

(CH3)3N Nitrogen attached to 3 carbon chains and 1 lone pair

Amines behave as bases due to lone pair of electrons on the nitrogen atom acts to accept a proton. When it accepts a proton, a dative covalent bond is formed.

Propylamine reacts with hydrochloric acid react to from the salt propylammonium chloride CH3CH2CH2NH2 + HCl —> CH3CH2CH2NH3+Cl- Ethylamine reacts with sulphuric acids to from ethylammonium sulphate 2 CH3CH2NH2 + H2SO4 —> (CH3CH2NH3+)2SO4^2-

reagents - excess alcoholic ammonia conditions - reflux under pressure nucleophile - ammonia (NH3) equation - C2H5Br + :NH3(acl) —> C2H5NH2 + HBr (or C2H5NH3+Br-)

Ammonia attacks halogenoalkanes because of lone pair. Amine produced also have a lone pair C2H5:NH2 so can also attack halogenalkane = substituted amines. Using excess ensure halogenoalkane react with ammonia before being able to react with any amine products.

Amines are bronsted-Lowry bases as can be proton acceptors They act as nucleophiles as lone pair attack electron deficient centre Boiling point = higher due to H bonds Solubility = low mass = more soluble also they form H bonds with other amines

Benzene * e- withdrawing so e- density on N and lone pair is less effective So decreases the strength of base Alkyl groups * e- releasing so e- density on N increasing so lone pair is more effective So increasing the strength of base

Amines + water —> weak alkaline solution CH3NH2(g) + H2O(l) <—> CH3NH3+(aq) + OH-(aq)

Amine + acid —> salt C6H5NH3+Cl-(aq) + NaOH(aq) —> C6H5NH3+Cl-(aq) Addition of NaOh(aq) - free base from its salt C6H5NH3+Cl-(aq) + NaOH(aq) —> C6H5NH2(l) + NaCl(aq) + H2O(l)

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Diethylamine is the stronger base as extra inductive effect of two alkyl groups compared to one. Diethylamine has greater electron density on N lone pair. Diethylamine therefore has greater ability to accept H+

Propylamine is the stronger base as the lone pair on phenylamine’s N id partially delocalised into e- ring (benzene). Propylamine has greater e- density on N lone pair so propylamine has greater ability to accept H+

See notes - amino acid is when the 2 functional groups amino and carboxylic acid are joined to the same carbon General formula = RCH(NH2)COOH

with acids The amine group acts as a base to produce salt (COOH)CHR(NH2) + HCl —> (COOH)CHE(N+H3) + Cl- with bases Carboxylic acid group acts to react to from salt and water (NH2)CHR(COOH) + NaOH —> (NH3)CHR(COO-Na+) + H2O

(NH2)CHR(COOH) + (OH)CH2CH3 —> (N+H3)CHRC=OOCH2CH3 +H2O

Can be L or R isomers- when produced these 2 steroidisomers form. Chiral molecules are non-superimposable *= chiral centre- carbons that are surrounded by 4 different group

CH3CH2Cl +NH3 —> CH3CH2NH3+Cl- Chloroethane + ammonia —> ethylammonium chloride

When monomers join up with expulsion of small molecules (often H2O or HCl) to form a polymer 2 molecules that react to produce a large molecule and a small molecule

1- the H group on the amine 2- the OH group on the carboxylic acid 3- the OH group on the alcohol Can also be a halogen group which reacts to form HX