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Alcohols and Phenols
General Formulas and Functional GroupsTwo of the three families contain a hydroxyl group (OH)AlcoholsPhenolsEthersOften made from alcohols and phenols
All are considered organic derivatives of water.
General Formulas
Bent moleculeCentral oxygen atomHydrogen and alkyl group attached (R) or an aryl group (Ar)
General Formulas ContAlcoholsR-O-HPhenolsAr-OHBenzene ring with an OHEthersR-O-R
Classification and Nomenclature of AlcoholsProperties of alcohols depend on the arrangement of the carbon atoms of the moleculePrimary (1) carbon atom
Secondary (2) carbon atom
Tertiary (3) carbon atom
Classification and Nomenclature of AlcoholsPrimary AlcoholRCH2OHSecondary AlcoholR2CHOHTertiary AlcoholR3COH
IUPAC NamingName the longest continous chain of carbons containing the OH groupNumber which carbon the OH is attached toEnd name in olIf more than one hydroxyl group, use suffixes diol, -triol, etc.
Physical Properties of Alcohols Replacement of hydrogen with a hydroxyl group greatly changes propertiesNot as homologous as alkanesHigher boiling pointsDue to strong intermolecular attractionsSolubilityThe more compact the molecule is, the more soluble it is4-5 carbons or lesssoluble in water
Preparation of AlcoholsHydration Reactions
Markovnikovs RuleThe hydroxyl group goes on the carbon with fewer hydrogens
Production of alcoholsMethanol
1.7 billion gallons produced a yearUsed in formaldehyde, acetic acid, fuels (MTBE), silicones, refrigerants
Production of AlcoholsEthanol Produced from sugars or starches by fermentation
C6H10O5 C6H12O6 2CH3CH2OH + 2CO2(Enzymes as catalysts)
Its the alcohol thats found in those certain beverages that people shouldnt drink
Production of Alcohols ContWines12% ethanolChampagnes14-20% ethanolBeers4% ethanolWhiskey50% ethanol
Proof spirit: alcoholic content of a beverage, twice that of the alcohol content by volume (whiskey: 100 proof)
Physiological Effects of AlcoholsLD50 (Lethal dose to 50% of a population)Tested on animalsVaries per species though
MethanolCan cause permanent blindness or death in high amountsVapors are very dangerous as well
EthanolToxic to humansAcute poisoning kills several hundred a year (drinking contests)Long term poisioningMost serious drug problem in US40 times more addicts than heroin
Isopropyl AlcoholRubbing alcoholRapid evaporationAntisepticMore toxic than ethanol, but induces vomittingUsed for the manufacture of acetone
Chemical Properties of AlcoholsReactionsOccur on the functional groupsMay involve hydrogen atoms as well
Dehydration Oxidation
DehydrationRemoval of waterSulfuric acid as a catalystProduces:Ether (excess ROH) + waterAlkene (excess H2SO4) + water
OxidationResult depends on if alcohol is primary, secondary, or tertiaryPrimaryProduces an aldehyde Then goes through further oxidation to produce a carboxylic acidSecondaryProduces a ketoneTertiaryNo reactionCant break the carbon-carbon bond
Oxidation Cont
Multifunctional Alcohols: Glycols and Glycerol
More than one hydroxyl groupPolyhydric groups Dihydric alcoholsTrihydric alcohols
GlycolsDihydric alcohols1,2 ethanediol (ethylene glycol)HOCH2CH2OHTwo hydroxyl groupsextensive intermolecular hydrogen bondingHigher boiling pointUsed as anti-freeze
GlycerolMost important trihydric alcoholSyrupy liquidNontoxic, product of the hydrolysis of fats and oilsNitroglycerinDetonates on slight impactReaction produces temps of 3000 C and pressures above 2000 atm
PhenolsSlightly acidicNeutralized by strong bases
PhenolsUsed as:AntisepticDisinfectants
First used was pure phenolproved to be too toxicMethyl derivativesCresolsCreosote
PhenolsDihydroxybenzenes
Components of biochemical molecules
EthersDerivatives of waterBoth hydrogen atoms are replaced
NamingSymmetricalName groups attached and add ether
PropertiesQuite inertAlthough react violently in the airLow boiling pointsno hydrogen bondsDiethyl etherForms a peroxide in airFirst general anesthetic