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Organic Chemistry II. University of Lincoln presentation. This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License. Aromatic Hydrocarbons.
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Organic Chemistry II University of Lincoln presentation This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Aromatic Hydrocarbons • Contain double or triple bonds, but do not show the same reactivity as other unsaturated hydrocarbons • Benzene: C6H6 • Used mainly as solvents • Substitution rather than Additionis favoured This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Resonance Structure:Rearrange the bonding electrons Delocalisation, Resonance: Stabilise molecules, so make them less reactive Three sp2 hybrid orbitals arrange themselves as far apart as possible -which is at 120° on a plane. The remaining p orbital is at right angles to them. Each carbon atom uses the sp2 hybrids to form σ-bonds with two other carbons and one hydrogen atom. Delocalised or Conjugated System: π-bonding electrons can move within the molecule Delocalised orbital clouds 6 p-orbitals This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Naming Aromatic Hydrocarbons Flurobenzene Ethylbenzene Toluene Aniline -ortho -meta 1,2-Dichlorobenzene Benzoic acid Phenol 1,3-Dichlorobenzene -para 1,4-Dichlorobenzene o-Xylene m-Bromostyrene 2,4,6-Trinitrotoluene (TNT) This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Reactions of Aromatic Hydrocarbons Substitution • Aromatic Substitution reaction – Aromatic compound loses a hydrogen atom and another atom or group takes its place. • It is possible for substitution to occur in more than one place on the ring. otha-Dinitrobenzene meta-Dinitrobenzene para-Dinitrobenzene This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Alcohols • –OH group (hydroxyl group) • Replace -e with -ol • CH3OH, methanol, simplest alcohols are classified as primary (1°), secondary (2°), or tertiary (3°) depending on the number of carbon atoms bonded to the carbon bearing the -OH group Primary Alcohol (1o) Secondary Alcohol (2o) Tertiary Alcohol (3o) This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Naming Alcohols methanol ethanol propanol 2-ethyl-1-butanol or 2-ethyl-butan-1-ol 2-propanol or propan-2-ol or isopropyl alcohol Polyhydroxy alcohols are alcohols that possess more than one hydroxyl group 1,2-Ethanediol (ethylene glycol) 1,2-propanediol (propylene glycol) 1,2,3-propanetriol (glycerol) This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Reactions of Alcohols ■ Reaction with acids to produce Esters Acetic Acid (ethanoic acid) Ethyl acetate ■ Redox reaction (Reduction and oxidation) Ethanol Acetaldehyde Acetic Acid Alcohol Dehydrogenase This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Ethers • –O- group (ether group) • CH3OCH3, dimethyl ether simplest • Soluble in water- H-bonding to water - Polar • Flammable – Ether can cause flash fires • Low Reactivity – Make Good Reaction Solvents • Naming: alkyl groups in alphabetical order followed by ether This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Aldehydes and Ketones • Both contain a carbonyl group (C=O) Aldehyde Ketone Naming Aldehydes Change -e ending to –al ethane ethanal (acetaldehyde) Ketones Change -e ending to –one propane propanone (acetone) This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Tertiary Alcohol Secondary Alcohol Reduction Oxidation Cannot be oxidised Reactions of Aldehydes and ketones Synthesis: produced by oxidation of alcohol Primary Alcohol Reduction Oxidation Reduction of carbonyl group to produce alcohols This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Oxidation of carbonyl group Strong Oxidation Reduction Reduction Oxidation Carboxylic acid This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Carboxilic acids • Contains C=O and –OH group on same carbon • Change -e to -oicacid • Acetic acid: acid in vinegar • Simplest: methanoic acid (formic acid) Methanoic acid Ethanoic acid Propanoic acid This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Reactions of Carboxilic acids ■ Esterification reactions Acetic Acid (ethanoic acid) Ethyl acetate ■ Reduction to aldehydes This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Ester • Derived from carboxylic acids and alcohols • Tend to be fragrant • Methyl butyrate apple • Ethyl butyrate pineapple • An ester name has two parts - the part that comes from the acid (propanoate) and the part that shows the alkyl group (methyl). Example: Methyl propanoate This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
R2OH R+ Ester H2O Acid R2NH base Amide Reactions of Esters Substitution Reduction of esters Hydrolisis of esters (basic) Carboxylate ester Sodium hydroxide Sodium Carboxylate Alcohol This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Amines • Derived from ammonia by substituting H for alkyl groups. It is an alkali • We have primary, secondary or tertiary amines depending on the number of H substituted Primary amine (1o) Secondary amine (2o) Tertiary amine (3o) Ammonia This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Amines 1,4-butanediamine Putrescine (found in decaying meat) (1o) Amphetamine (dangerous stimulant) (1o) Triethylamine (3o) Isopropylamine (1o) Piperidine 1,5-pentanediamine Cadaverine (found in the putrefaction of cadavers This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Reactions of Amines Alkylation Oxidation reduction Phenylamine This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Acknowledgements • JISC • HEA • Centre for Educational Research and Development • School of natural and applied sciences • School of Journalism • SirenFM • http://tango.freedesktop.org This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License