Organic Compounds Organic Compounds Typical organic compounds Contain

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Organic Compounds

Organic Compounds

Organic Compounds Typical organic compounds: • Contain carbon • Have covalent bonds • Have

Organic Compounds Typical organic compounds: • Contain carbon • Have covalent bonds • Have low melting points • Have low boiling points • Are flammable (all burn) • Are soluble in nonpolar solvents • May be gases, liquids or solids C 3 H 8 Propane

– Carbon: normally forms four covalent bonds and has no unshared pairs of electrons.

– Carbon: normally forms four covalent bonds and has no unshared pairs of electrons. C – Hydrogen: forms one covalent bond and no unshared pairs of electrons. H – Nitrogen: normally forms three covalent bonds and has one unshared pair of electrons. N. . – Oxygen: normally forms two covalent bonds and has two unshared pairs of electrons. . O. = – Halogen: normally forms one covalent bond and has three unshared. . pairs of electrons. . . Cl. .

Functional groups An atom or group of atoms within a molecule that shows a

Functional groups An atom or group of atoms within a molecule that shows a characteristic set of predictable physical and chemical properties. – A way to classify families of organic compounds. – They determine the chemical and physical properties of a molecule. – They undergo the same types of chemical reactions. – A way to name organic compounds.

Hydrocarbons Large family of organic compounds Composed of only carbon and hydrogen Saturated hydrocarbons

Hydrocarbons Large family of organic compounds Composed of only carbon and hydrogen Saturated hydrocarbons Unsaturated hydrocarbons Alkanes Alkenes, Alkynes & Aromatics C-C C=C C C

Carbon • Carbon has four valence electrons; hydrogen has one. • • C •

Carbon • Carbon has four valence electrons; hydrogen has one. • • C • H • • • To obtain an octet, carbon forms four bonds. H • • H C H • • H H CH 4 , methane

Alkanes

Alkanes

Methane Tetrahedral Expanded structural formula: showing each bond line. Molecular formula CH 4

Methane Tetrahedral Expanded structural formula: showing each bond line. Molecular formula CH 4

Ethane C 2 H 6 Molecular formula Expanded structural formula CH 3 – CH

Ethane C 2 H 6 Molecular formula Expanded structural formula CH 3 – CH 3 Condensed structural formula: with each carbon atom and its attached hydrogen atoms.

Alkanes Cn. H 2 n+2 n: number of carbon atoms

Alkanes Cn. H 2 n+2 n: number of carbon atoms

Naming of Alkanes Prefix + ane Cn. H 2 n+2

Naming of Alkanes Prefix + ane Cn. H 2 n+2

Line-angle Formula Propane CH 3 -CH 2 -CH 3 Butane CH 3 -CH 2

Line-angle Formula Propane CH 3 -CH 2 -CH 3 Butane CH 3 -CH 2 -CH 3 Pentane CH 3 -CH 2 -CH 3

Naming Substituents In the IUPAC system: • Removing a H from an alkane is

Naming Substituents In the IUPAC system: • Removing a H from an alkane is called alkyl group. -ane -yl • Halogen atoms are named as halo. -ine -O -OH -NO 2 Hydroxyl Nitro

Give the name of: CH 3─CH─CH 2─CH 3 STEP 1 Longest chain is butane.

Give the name of: CH 3─CH─CH 2─CH 3 STEP 1 Longest chain is butane. STEP 2 Number chain. CH 3─CH─CH─CH 3 1 2 3 4 STEP 3 Locate substituents and name. 2 -Methylbutane

Give the name of: CH 3─CH─CH─CH 3 STEP 1 Longest chain is butane. STEP

Give the name of: CH 3─CH─CH─CH 3 STEP 1 Longest chain is butane. STEP 2 Number chain. CH 3─CH─CH─CH 3 1 2 3 4 STEP 3 Locate substituents and name. 2, 3 -dimethylbutane

Cl CH 3─CH 2─CH─CH─CH 3 STEP 1 Longest chain is pentane. STEP 2 Number

Cl CH 3─CH 2─CH─CH─CH 3 STEP 1 Longest chain is pentane. STEP 2 Number chain from end nearest substituent. Cl CH 3─CH 2─CH─CH─CH 3 5 4 3 2 1 STEP 3 Locate substituents and name alphabetically. 3 -chloro-2 -methylpentane

CH 3 | | CH 3─CH─CH 2 ─CH─CH 3 1 2 3 4 2,

CH 3 | | CH 3─CH─CH 2 ─CH─CH 3 1 2 3 4 2, 4 -dimethylpentane 5 Cl CH 3 | | CH 3─CH 2─CH─CH 2─CH 3 | Cl 7 6 5 4 3 2 1 3, 5 -dichloro-3 -methylheptane

Br CH 3─CH─CH 2─Cl STEP 1 Longest chain has 4 carbon atoms. C─C─C─C STEP

Br CH 3─CH─CH 2─Cl STEP 1 Longest chain has 4 carbon atoms. C─C─C─C STEP 2 Number chain and add substituents. Br C ─ C ─ Cl 1 2 3 4 STEP 3 Add hydrogen to complete 4 bonds to each C. Br CH 3─CH─CH 2─Cl 2 -bromo-4 -chlorobutane

Constitutional Isomers • Have the same molecular formula. • Have different atom arrangements (different

Constitutional Isomers • Have the same molecular formula. • Have different atom arrangements (different structural formula). CH 3 CH 2 CH 3 Butane C 4 H 10 2 -Methylpropane C 4 H 10 CH 3 CHCH 3

Cyclic Hydrocarbon - Cycloalkane = Cyclobutane = Cyclopentane = Cyclohexane

Cyclic Hydrocarbon - Cycloalkane = Cyclobutane = Cyclopentane = Cyclohexane

Physical Properties of Alkanes • • • Nonpolar Insoluble in water. Lower density than

Physical Properties of Alkanes • • • Nonpolar Insoluble in water. Lower density than water. Low boiling and melting points. Gases with 1 -4 carbon atoms. (methane, propane, butane) • Liquids with 5 -17 carbon atoms. (kerosene, diesel, and jet fuels) • Solids with 18 or more carbon atoms. (wax, paraffin, Vaseline)

Boiling & melting points of Alkanes Number of carbon atoms ↑ Number of branches

Boiling & melting points of Alkanes Number of carbon atoms ↑ Number of branches ↑ CH 3 CH 2 CH 3 bp & mp ↑ bp & mp ↓ CH 3 CHCH 3

Chemical reactions of Alkanes Low reactivity 1 - Combustion: • Alkanes react with oxygen.

Chemical reactions of Alkanes Low reactivity 1 - Combustion: • Alkanes react with oxygen. • CO 2, H 2 O, and energy are produced. • Alkane + O 2 CH 4 + 2 O 2 CO 2 + H 2 O + heat CO 2 + 2 H 2 O + energy

Chemical reactions of Alkanes Low reactivity 2 - Halogenation: Alkanes react with Halogens. CH

Chemical reactions of Alkanes Low reactivity 2 - Halogenation: Alkanes react with Halogens. CH 4 + Cl 2 Heat or light CH 3 Cl+ Cl 2 CH 2 Cl 2+ Cl 2 CHCl 3+ Cl 2 Heat or light CH 3 Cl + HCl Chloromethane CH 2 Cl 2 + HCl Dichloromethane CHCl 3 + HCl Trichloromethane CCl 4 + HCl Tetrachloromethane

Sources of Alkanes • Natural gas – 90 to 95 percent methane – 5

Sources of Alkanes • Natural gas – 90 to 95 percent methane – 5 to 10 percent ethane, and – a mixture of other low-boiling alkanes, chiefly propane, butane, and 2 methylpropane. • Petroleum – A thick liquid mixture of thousands of compounds, most of them hydrocarbons formed from the decomposition of marine plants and animals.

Alkenes and Alkynes

Alkenes and Alkynes

Alkenes and Alkynes Saturated compounds (alkanes): Have the maximum number of hydrogen atoms attached

Alkenes and Alkynes Saturated compounds (alkanes): Have the maximum number of hydrogen atoms attached to each carbon atom. Unsaturated compounds: Have fewer hydrogen atoms attached to the carbon chain than alkanes. • Containing double bond are alkenes. Cn. H 2 n • Containing triple bonds are alkynes. Cn. H 2 n-2

Naming Alkenes & Alkynes Using the IUPAC alkane names: Alkene names change the end

Naming Alkenes & Alkynes Using the IUPAC alkane names: Alkene names change the end to -ene. Alkyne names change the end to -yne

Give the location for double and triple bond

Give the location for double and triple bond

Naming Alkenes & Alkynes CH 2= CH ─ CH 2─ CH 3 1 3

Naming Alkenes & Alkynes CH 2= CH ─ CH 2─ CH 3 1 3 2 4 CH 3─ CH=CH─ CH 3 1 2 3 2 3 2 -methyl-2 -butene 1 CH 3─ C C ─ CH 3 1 2 -butene 4 CH 3 | CH 3─ CH=C─CH 3 4 1 -butene 4 2 -butyne

Naming Alkenes & Alkynes CH 3─ CH 2─ C C ─ CH 3 5

Naming Alkenes & Alkynes CH 3─ CH 2─ C C ─ CH 3 5 4 3 2 2 -pentyne 1 CH 3─ CH 2─ C=CH ─ CH 3 5 4 3 2 3 -methyl-2 -pentene 1 CH 2 – CH 3─ CH 2─ C=CH ─ CH 3 5 4 3 2 1 3 -ethyl-2 -pentene

Chemical properties of Alkenes & Alkynes More reactive than Alkanes Addition of Hydrogen (Hydrogenation-Reduction)

Chemical properties of Alkenes & Alkynes More reactive than Alkanes Addition of Hydrogen (Hydrogenation-Reduction) Addition of Hydrogen Halides (Hydrohalogenation) Addition of water (hydration) Addition of Bromine & Chlorine (Halogenation)

Chemical properties More reactive than Alkanes Hydrogenation: • A hydrogen atom adds to each

Chemical properties More reactive than Alkanes Hydrogenation: • A hydrogen atom adds to each carbon atom of a double bond. • A catalyst such as platinum is used. H H │ │ H–C=C–H + H 2 H H Pt Pt │ │ H– C – C– H │ │ H H ethene ethane

Chemical properties More reactives than Alkanes Halogenation: • A halogen atom adds to each

Chemical properties More reactives than Alkanes Halogenation: • A halogen atom adds to each carbon atom of a double bond. • Usually by using an inert solvent like CH 2 Cl 2. H H │ │ CH 3–C=C–CH 3 + Cl 2 2 -Butene CH 2 Cl 2 CH 3– C – C– CH 3 │ │ Cl Cl 2, 3 -Dichlorobutane

Aromatic Hydrocarbons

Aromatic Hydrocarbons

Aromatic Compounds Aromatic compounds contain benzene. Benzene has: • 6 C atoms and 6

Aromatic Compounds Aromatic compounds contain benzene. Benzene has: • 6 C atoms and 6 H atoms. • Two possible ring structures.

Aromatic Compounds Arene: A compound containing one or more benzene rings. Aromatic compounds are

Aromatic Compounds Arene: A compound containing one or more benzene rings. Aromatic compounds are named: • With benzene as the parent chain. • Name of substituent comes in front of the “benzene”. CH 3 Cl methylbenzene chlorobenzene CH 2 -CH 3 ethylbenzene

Naming of Aromatic Compounds Some substituted benzenes have common names. CH 3 Toluene

Naming of Aromatic Compounds Some substituted benzenes have common names. CH 3 Toluene

Naming of Aromatic Compounds When two groups are attached to benzene, the ring is

Naming of Aromatic Compounds When two groups are attached to benzene, the ring is numbered to give the lower numbers to the substituents. - Start numbering from special name (if we have). - If we do not have, number them to get the smallest set of numbers. - Name them by alphabetical order. 3 -methyltoluene Ortho Meta Para

Naming of Aromatic Compounds If we have three or more substituents: -Start numbering from

Naming of Aromatic Compounds If we have three or more substituents: -Start numbering from special name (if we have). -If we do not have, number them to get the smallest set of numbers. -Name them by alphabetical order.

Chemical properties of benzene Resonance: stable No addition reactions (almost unreactive) Halogenation Nitration Sulfonation

Chemical properties of benzene Resonance: stable No addition reactions (almost unreactive) Halogenation Nitration Sulfonation

Chemical properties of benzene Halogenation Nitration

Chemical properties of benzene Halogenation Nitration