CHAPTER 27 - AMINES, AMINO ACIDS, AND POLYMERS Flashcards
What is an amine?
An organic compound, derived from ammonia, NH3, in which one or more hydrogen atoms in ammonia have been replaced by a carbon chain or ring
What are the two types of amine
Aliphatic amine - straight chain
Aromatic amine - Aromatic ring
What are the types of amine classification
Primary, secondary, tertiary
depending on how many of the Hydrogens have been replaced with carbon chains/rings
What are 2 examples of amines in nature
Serotonin - acts as a neurotransmitter, responsible for control of appetite, sleep, memory, learning, temperature regulation, muscle contraction and depression
Pseudoephedrine - active ingredient in medications such as nose drops and cold remedies - shrinks nasal membranes and inhibits nasal secretions
What compounds are mainly responsible for the smell of a decomposing organism - eg. rotten fish
Amines and sulfur compounds
How do Amines act as bases
Lone pair of electrons on the nitrogen can accept a proton
eg ethylamine + H+ = Ethylammonium ion +
What is added to amines to create a salt?
Acids
eg propylamine + HCl = Propylammonium chloride
What does ammonia act as in a substitution reaction with a haloalkane
Nucleophile, due to its lone pair of electrons
What are the conditions and reaction to form a primary amine (aliphatic)?
Alkane + Ammonia = Salt
Salt + NaOH = Amine + NaCl + Water
Conditions -
Excess ammonia - Reduces further substitution of the amine group to form secondary and tertiary amines
Ethanol solvent - prevents substitution of haloalkane by water to produce alcohols
*still has lone pair which means further substitution can occur
Eg. page 476 textbook
What are the conditions to form and reaction of secondary and tertiary amines (aliphatic)?
Secondary
Haloalkane + Propylamine = Salt
Salt + NaOH = Amine + NaCl + Water
Further substitution to form tri-amines
pg 476 in textbook
How are Aromatic Amines prepared?
Reduction of benzene
Nitrobenzene heated by reflux w Sn and conc HCl
forms ammonium salt
Salt reacts with excess NaOH to produce Aromatic Amine (+water)
What was the first synthetic dye and what is it based on?
Mauvine
Based on Phenylamine
What is an amino acid
An organic compound containing both NH3 and COOH functional groups
What is the general formula for an Alpha amino acid
RCH(NH2)COOH
What will occur if an amino acid reacts with an acid
A Salt will be formed (amine group mostly)
What happens when an amino acid is reacted with an alkali / Alcohol?
Alkali: Salt
Alcohol: Ester
(COOH group reacts)
How are amino acids esterified?
Heating with alcohol and concentrated sulfuric acid
Forms NH3+ and Ester
What is a zwitterion?
An amino acid that has accepted a proton from the carboxylic acid and given to the amine
NH3+ and COO-
What is the isoelectric point?
The pH at which the zwitterion is formed
What happens when an amino acid is added to a solution with a pH either side of its isoelectric point
Lower than IEP - Amino acid acts as a base and gains a proton (NH3+)
Higher than IEP - Amino acid acts as an Acid, Loses a proton (COO-)
What is an amide?
The product of reactions of acyl chlorides with ammonia and amines
Describe the structure of a primary, secondary and tertiary amide
Primary C=O-NH2
Secondary C=O NH-CH3
Tertiary C=ON-(CH3)2
Pg 480 for diagram
What is stereoisomerism
Compounds with the same structural formula but a different arrangement of atoms
What is a chiral centre?
A carbon atom that is attached to 4 different atoms or groups of atoms
What are enantiomers
Non-superimposable mirror image structures
(eg hands, looking in a mirror)
What is condensation polymerisation?
Joining of monomers and producing water ( or HCl)
How are Polyesters formed?
Reaction of Alcohols an/or Carboxylic acid group
What are Polyamides?
Condensation polymers formed when monomers are joined together by amide linkages in a long chain to forma polymer
What can Hydrolyse Polyesters
Acids and bases
Base hydrolysis forms 2 salt ends (eg COO-Na+ using NaOH as base)
Acid Hydrolysis gives 2 COOHs using any acid
Page 486 for diagram
What can hydrolyse polyamides?
Acids and bases
Base hydrolysis forms 2 salt ends (COO-Na+) and 2 NH2 ends using NaOH
Acid Hydrolysis forms 2 COOH ends and 2 NH3+ ends
What is the difference between addition and condensation polymerisation?
Addition - double bond is broken, group is added on
Condensation - Groups interact and usually create by-product eg water
