21/10/99 Organic Chemistry

What makes a compound organic? BELL RINGER 21/10/99 What makes a compound organic?

Origin of organic compounds 21/10/99 Origin of organic compounds Naturally occurring organic compounds are found in plants, animals, and fossil fuels All of these have a plant origin All of these rely on the “fixing” of C from CO2 Synthetic organic compounds are derived from fossil fuels or plant material

C C C C C Introduction Most current research focuses on Organic 21/10/99 Introduction Most current research focuses on Organic Originally from “organic” meaning life Not just chemistry of life, chemistry of carbon Exceptions: oxides of carbon (CO2, CO) carbonates,bicarbonates(NaHCO3,CaCO3) cyanides (NaCN, etc) C C C One C with no H, or with metal Carbon can form four bonds… C C

Properties of Organic Compounds 21/10/99 Properties of Organic Compounds Covalently bonded Low Melting Points Non-electrolytes Nonpolar React slower than inorganic compounds Require high activation energies Insoluble in water ~ generally

Carbon forms four bonds 21/10/99 Carbon forms four bonds Carbon can form four bonds, and forms strong covalent bonds with other elements This can be represented in many ways …

21/10/99 Functional groups Functional groups are parts of molecules that result in characteristic features About 100 functional groups exist, we will focus on about 10 Useful to group the infinite number of possible organic compounds Ex - the simplest group is hydrocarbons Made up of only C and H Not really a functional “group” Further divided into: Aliphatics - Alkanes, Alkenes, Alkynes Aromatics

Hydrocarbons Alkanes C C Alkenes C C CnH2n+2 CnH2n Alkynes C C 21/10/99 Hydrocarbons Alkanes C C Alkenes C C CnH2n+2 CnH2n Alkynes C C Aromatics CnH2n-2

Naming Hydrocarbons (nomenclature)

Drawing structures: it’s all good 2-butene This is called the “condensed structure” On a test, choose a method that shows all H’s CH3CH=CHCH3 Using brackets can also shorten some formulas: CH3(CH2)4CH3 vs. CH3CH2CH2CH2CH2CH3

Draw/Name the following Octane 1-hexyne Propene C H C H C H C H 2-pentene

What is the structural formula for 2-hexene BELL RINGER 21/10/99 What is the structural formula for 2-hexene CH3CHCHCH2CH2CH3

Hydroxyl, carbonyl, carboxyl 21/10/99 Hydroxyl, carbonyl, carboxyl There are other names that describe patterns of atoms that are parts of functional groups. “Hydroxyl” refers to –OH “Carbonyl” refers to C=O “Carboxyl” refers to COOH

Naming: common vs. IUPAC Common names used in the 1800’s are still used for some compounds today: Acetone Formic acid Acetylene The International Union of Pure and Applied Chemistry (IUPAC) was established in 1900s

Numbering carbons 1-pentene Q- draw pentene A- Where’s the bond? We number C atoms Thus, naming compounds with multiple bonds is more complex than previously indicated Only if 2+ possibilities exist, are #s needed Always give double bond the lowest number Try to name these: C2H4 CH3CH2CCCH2CH2CH2CH2CH3 2-butene Ethene 3-nonyne

Branched Hydrocarbons 3 Names are made up of: side chains, root 2,3-dimethylpentane Root is the longest possible HC chain Must contain multiple bonds if present Add -yl to get name of side chain Common side chains include: CH3- methyl CH3CH2- ethyl CH3CH2CH2- propyl (CH3)2CH- isopropyl Br- (bromo), Cl- (chloro), F- (fluoro), I- (iodo)

Naming side chains Rule 1: choose the correct ending -ane C H C H C H 3 2 3 C H C H CH C H C C H 3 2 2 3 C H 3 Rule 1: choose the correct ending -ane

Naming side chains Rule 2: longest carbon chain ane C H C H C H C H C 3 2 3 C H C H CH C H C C H 3 2 2 3 C H 3 Rule 2: longest carbon chain ane

Naming side chains Rule 3: attach prefix (according to # of C) ane 2 3 C H C H CH C H C C H 3 2 2 3 C H 3 Rule 3: attach prefix (according to # of C) ane Heptane

Naming side chains Rule 4: Assign numbers to each carbon heptane C H C 3 2 2 3 3 2 1 C C H H C C H H CH C C C H H C C C C H H 3 3 2 2 2 2 3 3 3 7 6 5 4 C C H H 3 3 Rule 4: Assign numbers to each carbon heptane

Naming side chains Rule 5: Determine name for side chains heptane methyl C H C C H H C C H H 2 2 3 3 3 6 7 5 4 3 2 1 C C H H C C H H C CH C C H H C C C C H H 3 3 2 2 2 2 3 3 methyl C C H H 3 3 methyl Rule 5: Determine name for side chains heptane

Naming side chains Rule 6: attach name of branches methyl C H C H C H 3 2 3 6 7 5 4 3 2 1 C H C H CH C H C C H 3 2 2 3 methyl C H 3 methyl Rule 6: attach name of branches 3-methyl-3-methyl-5-methyl-heptane

Naming side chains Rule 8,9: group similar branches methyl C H C H C H 3 2 3 6 7 5 4 3 2 1 C H C H CH C H C C H 3 2 2 3 methyl C H 3 methyl Rule 8,9: group similar branches 3-methyl-3-methyl-5-methyl-heptane

Naming side chains Rule 8,9: group similar branches methyl C H C H C H 3 2 3 6 7 5 4 3 2 1 C H C H CH C H C C H 3 2 2 3 methyl C H 3 methyl Rule 8,9: group similar branches 3,3,5-trimethyl-heptane

BELL RINGER H H H H H C H C H C H H C H H H H H C – C – C – C = C – C 21/10/99 H H Name the hydrocarbon H H H C H C H C H H C H H H H H C – C – C – C = C – C H H H H H H C H H 4-ethyl-3-methyl-4-octene

Naming side chains 3-methylhexane 4-ethyl-2,3-dimethylheptane 5-ethyl-2,4,6-trimethyloctane

Functional Groups Alcohols -OH -name ends in –ol 2-butanol Element Grouping: -name ends in –ol Naming: Example: 2-butanol

Odorless, colorless, sweet and syrupy, toxic liquid Functional Groups Alcohols Ethylene glycol  1,2 Ethanediol                                        C HO H OH Odorless, colorless, sweet and syrupy, toxic liquid

Functional Groups Aldehydes C O H -name ends in –al ethanal Element Grouping: -name ends in –al Naming: Example: ethanal

Functional Groups Ketones O C -name ends in –one propanone Element Grouping: -name ends in –one Naming: Example: propanone

Functional Groups Organic Acids OH C O butanoic acid Element Grouping: -name ends in –oic acid Naming: Example: butanoic acid

Name the following organic compound: BELL RINGER 21/10/99 Name the following organic compound: C – C – C – C – C – C H O 3-hexanone

Functional Groups Ethers -O- -name ends in ether methyl propyl ether Element Grouping: -name ends in ether Naming: Example: methyl propyl ether

Functional Groups Halides Cl C F C Br C I C 2-chloro-3-fluoro-butane Element Grouping: Br C I C Naming: -use prefix with o ending CH3-CH-CH-CH3 Cl F Example: 2-chloro-3-fluoro-butane

Functional Groups Amine N propanamine C H C H C H N H2 Element Grouping: -name ends in –amine Naming: C H C H C H N H2 Example: 3 2 2 propanamine

Functional Groups Amino Acids OH C O N H X TOO complicated Element Grouping: Naming: TOO complicated Example:

Functional Groups Esters O C propyl methanoate -name ends in –oate Element Grouping: -name ends in –oate Naming: Example: propyl methanoate

Functional Groups Amide NH2 C O NH2 C O H methanamide Element Grouping: -name ends in –amide Naming: NH2 C O H Example: methanamide

Drawing Side Chains 2,2-dimethyloctane 1,3-dimethylcyclopentane CH3CH2CH2CH2CH2CH2-C-CH3 CH3 1,3-dimethylcyclopentane C H3C CH3 H CH2CHCH2CH2CH2-C-CH2 CH3 CH3CH2CH2 CH2CH3 6-ethyl-5-propyl-7-methyl-1-heptene

BELL RINGER C – C – C – O – C – C H O Name the hydrocarbon 21/10/99 Name the hydrocarbon C – C – C – O – C – C H O ethyl propanoate

21/10/99 Isomers

Structural Isomers 1-butene 2-butene H 3 C H 3 2 Butane (C4H10) 2-methylpropane (C4H10) 1-butene 2-butene 2-methylpropene cyclobutane methylcyclopropane

Structural Isomers 2-propanol 1-propanol ethyl-methyether C H OH C H

Covalent Molecules Lab

Draw and name an isomer of butanal. BELL RINGER 21/10/99 Draw and name an isomer of butanal.

Many reactions require a catalyst to lower the activation energy 21/10/99 Organic Reactions Generally organic reactions occur at a slower rate  covalent bonds Many reactions require a catalyst to lower the activation energy

Types of Reactions Addition F2 -alkene or alkyne H F –C–C– –C=C– H +  21/10/99 Types of Reactions Addition -alkene or alkyne Reactants: -a double halogenated halocarbon Produces: Example: H F –C–C– –C=C– H F2 +  -only occurs with unsaturated hydrocarbons Special Info: -results in 2 atoms added

Special type of Addition 21/10/99 Special type of Addition “Hydrogenation” H–C–C–C–C–H H H–C–C–C=C–H H                                                                              + H2 Helps turn oils into margarine

Types of Reactions Substitution HI I2 H–C–C–C–C–H H I H–C–C–C–C–H H + 21/10/99 Types of Reactions Substitution Reactants: saturated hydrocarbon and halogen -a single halogenated halocarbon Produces: Example: H–C–C–C–C–H H I H–C–C–C–C–H H HI + I2 + Special Info: -only occurs with alkanes, can add more by doing more than one substitution

Types of Reactions Fermentation -sugar and yeast H OH –C–C– CO2 + 2 21/10/99 Types of Reactions Fermentation -sugar and yeast Reactants: Produces: Alcohol and carbon dioxide Example: H OH –C–C– CO2 + 2 yeast

Types of Reactions Esterification -organic acid and an alcohol H –C–H 21/10/99 Types of Reactions Esterification -organic acid and an alcohol Reactants: Ester and water by dehydration synthesis Produces: Example: H –C–H HO + –C – C– OH O O H HOH H–C–C–O–C–H +

Esterification - DEMOS 21/10/99 Types of Reactions Esterification - DEMOS Acetic Acid + Ethanol Ethyl ethanoate + Water (ethanoic acid) H –C–C-H HO + –C – C– OH O HOH + O H H–C–C–O–C–C–H Smells Like: Fruity?

21/10/99 What is the name of the ester made between the reaction of pentanol and acetic acid? H–C–C– H OH O HO H –C–C–C–C–C–H + H–C–C– H O –C–C–C–C–C–H + HOH Smells Like: Banana? Pentyl ethanoate

21/10/99 What is the name of the ester made between the reaction of methanol and salicylic acid? Smells Like: wintergreen + HOCH3 + H2O Methyl benzoate (Methyl salicylate)

Almost the reverse of esterification (hydrolysis) Types of Reactions 21/10/99 Saponification Almost the reverse of esterification (hydrolysis) Reactants: - a fat and a strong base Soap(salt of an acid) and glycerol Produces: Example:

Combustion (oxidation) 21/10/99 Types of Reactions Combustion (oxidation) -hydrocarbons and oxygen Reactants: -hydrocarbons and limited O2 Produces: CO2 and H2O CO and H2O Example:  O2 + –C–C–C– H 3 4 5 CO2 H2O +

Types of Reactions Polymerization many small molecules 21/10/99 Types of Reactions Polymerization many small molecules Reactants: -amino acids, ethylene Produces: Protein, plastics Example: C=C H 200 C=C H 200

BELL RINGER 21/10/99 Draw the structural formula for the product of joining two alcohols together: Propyl ethyl ether

BELL RINGER 21/10/99 Draw the structural formula for the product of joining two alcohols together: Propyl ethyl ether C – C – C – O – C – C H

Alcohols and organic acids are polar Some additional info Solubility Hydrocarbons are non-polar Alcohols and organic acids are polar = Soluble in water

Some additional info MP & BP STRONG H Bonds Alcohols and organic acids The presence of H bonds increases strength of IMF’s Alcohols and organic acids STRONG H Bonds Amines weaker H Bonds

Saturated vs. unsaturated Some additional info Saturated vs. unsaturated with respect to Hydrogen's Alkanes only SATURATED  Alkenes or Alkynes UNSATURATED  Aka ‘trans fats’  from hydrogenation ‘Cis’ fat ‘Trans’ fat

Fractional Distillation Further purification – done by cracking and polymerization Cracking Chemical breakdown of more complex molecules into smaller ones

H. Fractional Distillation Lighter hydrocarbons have lower melting points CH4 C2H8 Gases at room temperature Liquid at room temperature C8H18 Petroleum = mixture of all different hydrocarbons Heat mixture slowly. The different hydrocarbons are boiled to a gas and allowed to rise As they rise, they cool off until they become liquids Heavier hydrocarbons will not rise as high before they become liquids Lightest hydrocarbons will rise the highest

Organic Reaction Review Bell Ringer Organic Reaction Review Organic Reaction Compound formed 1. Esterification 4 Ethanol 2 Glycerol 2. Saponification 5 Fluoroethane 3. Polymerization 3 Polyethylene 4. Fermentation 6 Dichloropropane 5. Substitution 1 Methyl ethanoate 6. Addition

Examples - Perform the following reactions, identify each as addition or substitution, and draw the products H H H | | | H--C--C--C--H H H H H H H | | | H--C--C--C--H Cl H H Substitution reaction A. + Cl2 + HCl H H H | | | H--C--C==C--C--H | | | H H H Cl H Br H | | | | H--C--C--C--C--H H Br H H H H Br H | | | | H--C--C--C--C--H H Br H H + Br2 + Cl2 B. addition reaction + HCl H | H-- C  C--C--H Substitution reaction H H \ | C == C--C--H / | | F F H addition reaction C. + F2 Notice the cis! I I | | H--C--C--H 2 addition reactions D. H--C C--H + 2 I2

Examples - Write out the products of the esterification, then write the molecular formula of the ester O || H--C--OH H H H H | | | | HO--C--C--C--C--H H H H H O || H--C-- H H H H | | | | O--C--C--C--C--H H H H H + H2O Butyl methanoate H H H O | | | H--C--C--C--H H H H O H || | HO--C--C--H | H H O | || H--C--C-- | H H H H | | | O--C--C--C--H H H H Propyl ethanoate