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