Organic Compounds
Organic Halides A hydrocarbon in which one or more hydrogen atoms have been replaced by halogen atoms Freons (chlorofluorocarbons) in refrigeration and air conditioning Teflon (polytetrafluoroethane) DDT, PCBs
Naming Organic Halides Consider halogen as a branch. Properties of Organic Halides Halogen makes the molecule more polar, increasing strength of the intermolecular forces Higher boiling points than their corresponding hydrocarbons More soluble in polar solvents Molecules with more halogens are more polar
Preparing Organic Halides Recall: Substitution reaction produce halides in alkanes and aromatic hydrocarbons
Preparing Organic Halides Recall: alkyl halides are produced in halogenation reactions with hydrocarbons
Elimination Reactions Preparing alkenes from alkyl halides Most common method of preparing alkenes Alkyl halides can eliminate a hydrogen and a halide ion from adjacent carbon atoms forming a double bond. Presence of a hydroxide ion is required
Alcohols Organic compounds containing a hydroxyl group -OH E.g. ethanol, cholesterol, retinol (vitamin A) Naming: -ol suffix e.g. methane + OH = methanol
Polyalcohols Alcohols containing more than one -OH group -diol, -triol suffix Or hydroxy prefix 1,2-dihydroxyethane 1,2,3-trihydroxypropane
Properties of Alcohols More polar and can hydrogen bond Higher boiling points More soluble in polar solvents Long-chain alcohols are nonpolar (hydrocarbon portion) and polar (-OH) Ideal solvents in organic reactions because they will dissolve both polar and nonpolar compounds
Hydration Reactions Alkene + water --> alcohol Follows Markovnikov s rule Combustion of Alcohols
Elimination Reactions Dehydration (Condensation) Reactions: Under certain conditions alcohols can decompose to produce alkenes and water A catalyst (sulfuric acid) removes a hydrogen atom and a hydroxyl group from neighbouring carbons Resulting in C=C and H 2 O
Ethers Molecules with C-O-C group More polar than hydrocarbons But, unlike alcohols, ethers cannot hydrogen bond Naming: Add oxy to the prefix of the smaller hydrocarbon group and join it to the alkane name of the larger hydrocarbon group E.g. CH 3 -O-C 2 H 5 is methoxyethane
Condensation Reactions When two alcohols combine, an ether and water are formed
Aldehydes and Ketones Ketone: Molecule with a carbonyl group (C=O) between two carbon atoms. Alkane name with -one suffix Aldehyde: Molecule with a carbonyl group (C=O) on a terminal carbon. Alkane name with -al suffix
Properties of Aldehydes and Ketones Lower boiling point and less soluble in water than alcohols (no -OH) More polar than hydrocarbons (higher boiling points and more soluble) Good solvents (both polar and nonpolar)
Oxidation Reactions Alcohol + an oxidizing agent (removes electrons) to form an aldehyde or ketone and water The oxidizing agent removes two H-atoms (one from the -OH group and one from the adjacent carbon) resulting in C=O and H 2 O
No available H-atom Oxidizing agent
Hydrogenation Reactions The C=O double bond can undergo an addition reaction with hydrogen to form an -OH group. Aldehydes always produce 1 alcohols Ketones always produce 2 alcohols
Carboxylic Acids Molecules with a carboxyl group -COOH E.g. lactic acid, citric acid Alkane name with -oic acid E.g. methanoic acid
Properties of Carboxylic Acids Polar and can hydrogen bond Similar properties to alcohols (smaller members are soluble in water, larger members are insoluble) ph < 7 (H-atom in -OH group)
Oxidation Reactions Recall: A 1 alcohol can be oxidized to form an aldehyde. An aldehyde can be further oxidized to form a carboxylic acid A ketone cannot be oxidized because there is mo free H-atom
Oxidation Reaction
Esterfication Recall: acid + base --> salt + water (neutralization reaction) Carboxylic acid + alcohol --> ester + water Properties of Esters Similar to carboxylic acids, but lacking -OH group Esters are less polar (less soluble in water), lower boiling points (no H-bonds) Not acidic
Naming Esters 1st part is the name of the alkyl group in the alcohol 2nd part is the ending of the acid name changed from -oic to -oate
Amines An ammonia molecule in which one or more H-atoms are substituted by alkyl or aromatic groups Naming: Amino + alkane name OR Alkyl group + amine
Naming 2 and 3 Amines N- prefix used for the substituted groups on the nitrogen atom Alkyl groups are listed alphabetically N,N-dimethyl-2-aminopropane
Properties of Amines N-C, and N-H polar bonds H-bonding occurs but N-H is less polar than O-H
Synthesizing Amines from Alkyl Halides Alkyl halide + ammonia --> 1 amine + HX Alkyl halide + 1 amine --> 2 amine + HX Alkyl halide + 2 amine --> 3 amine + HX
Synthesizing Amines from Alkyl Halides
Amides Similar to esters, except N instead of O Recall: Carboxylic acids + alcohols --> esters + water Carboxylic acids + ammonia/1 /2 amines--> amides + water
Naming Amides 1st part is the name is from the amine 2nd part is the ending of the acid name changed from -oic to -amide Alphabetical order with N- groups N-ethyl propanamide
Summary