Amines

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Chapter 16
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• Amines

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Ammonia Derivatives
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Classification
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• Primary CH3NH2
• Secondary CH3NHCH3
• Tertiary (CH3)3N
• Quaternary Salt (CH3)3NH

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Heterocyclic Aliphatic Amines
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• piperidine

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Heterocyclic Aromatic Amines
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• pyridine

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Nomenclature
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• Name as alkyl derivative
• CH3NH2 methylamine
• CH3NHCH3 dimethylamine
• CH3NHCH2CH3 ethylmethylamine
• (CH3)3N trimethylamine
• (CH3)3NH Cl- trimethylammonium chloride

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• Aniline derivatives
• Name these compounds

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Acid-Base Properties
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• Amines are basic
• Ammonia (review)
• NH3 H2O ? NH4 OH-
• Amines
• CH3NH2 H2O ? CH3NH3 OH-

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Amines and Acids
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• CH3NH2 HCl ? CH3NH3 Cl-
• methylammonium chloride

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Physical Properties
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• Boiling point
• 1 and 2 have hydrogen bonding
• no hydrogen bonding for 3
• CH3CH3 -89C
• CH3NH2 -6C
• CH3OH 65C

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• Solubility
• Carbon to nitrogen ratio lt 41 soluble
• 1 gt 2 gt 3
• Odor lachrymatory
• 1,4-butanediamine putrascine
• 1,5-pentanediamine -- cadaverine

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Chemical Properties
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• Acid-base reactions
• alkylamine acid
• ? alkylammonium ion anion from acid
• methylamine HCl
• ? methylammonium chloride
• CH3NH2 HCl ? CH3NH3 Cl-

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Solubility Switch
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• alkylamine ACID ? alkylammonium salt
• (insoluble) (soluble)
• (not charged) (charged)
• carboxylic acid BASE ? carboxylate salt
• (insoluble) (soluble)
• (not charged) (charged)

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Summary
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• Boiling point (Intermolecular Forces)
• hydrocarbonsltetherslt3 amines
• lt1 and 2 amines lt alcohols
• Solubility (C4 rule) (Polarity and ability to
  hydrogen bond with water)
• hydrocarbonsltetherslt3 amines
• lt1 and 2 amines lt alcohols lt diols