Simple Organic Chemistry Basic Structure and Nomenclature Adapted from http://www.sciencegeek.net/APchemistry/Powerpoints.shtml

Condensed Structural Formula = CH3(CH2)nCH3 First Ten Alkanes Formula Name CH4 Methane C6H14 Hexane C2H6 Ethane C7H16 Heptane C3H8 Propane C8H18 Octane C4H10 Butane C9H20 Nonane C5H12 Pentane C10H22 Decane Alkane = CnH2n+2 Condensed Structural Formula = CH3(CH2)nCH3

Straight Chain Alkanes aren’t “Straight” C – C bonds are sp3 hybridized Butane, C4H10 Decane, C10H22

Rules for Naming Alkanes (Nomenclature) 1. For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon 1 2 3 4 4 carbon chain = butane

Rules for Naming Alkanes (Nomenclature) 2. When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl. —CH3 Methyl —CH2CH3 Ethyl —CH2CH2CH3 Propyl —CH2CH2CH2CH3 Butyl Methyl

Rules for Naming Alkanes (Nomenclature) 3. The positions of substituent groups are specified by numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching. 1 2 3 4 Methyl

Rules for Naming Alkanes (Nomenclature) 4. The location and name of each substituent are followed by the root alkane name. The substituents are listed in alphabetical order (irrespective of any prefix), and the prefixes di-, tri-, etc. are used to indicate multiple identical substituents. 1 2 3 4 Name: 2-methylbutane Methyl

Nomenclature Practice Name this compound 1 9 carbons = nonane 2 4 3 5 6 7 8 9 Step #1: For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon

Nomenclature Practice Name this compound 9 carbons = nonane 1 2 4 3 5 6 CH3 = methyl 7 chlorine = chloro 8 9 Step #2: When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl.

Nomenclature Practice Name this compound 9 carbons = nonane 1 2 4 3 5 6 CH3 = methyl 7 chlorine = chloro 8 9 1 9 NOT 9 1 Step #3: The positions of substituent groups are specified by numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching.

Nomenclature Practice Name this compound 9 carbons = nonane 1 2 4 3 5 6 CH3 = methyl 7 chlorine = chloro 8 9 2-chloro-3,6-dimethylnonane Step #4: The location and name of each substituent are followed by the root alkane name. The substituents are listed in alphabetical order (regardless of any prefix), and the prefixes di-, tri-, etc. are used to indicate multiple identical substituents.

Cyclic Alkanes Cyclopropane, C3H6 Cyclobutane, C4H8 Cyclopentane, C5H10 Cyclohexane, C6H12 Cycloheptane, C7H14 Remember, explicit hydrogens are left out

Structural Isomers Isomers are molecules with the same chemical formula, but different organization of atoms (different bonding) n-Pentane, C5H12 2-methylbutane, C5H12 2,2-dimethylpropane, C5H12

Alkenes Contain Carbon-Carbon Double bonds Each carbon is sp2 hybridized Ethene 1  bond Alkenes are considered unsaturated

Geometric Isomerism in Alkenes Unhybridized p orbitals must align, so bond cannot rotate cis-2-butene trans-2-butene

Alkynes Contain Carbon-Carbon Triple Bonds Each carbon is sp hybridized Ethyne 1  bond 1  bond Alkynes are considered unsaturated

Reactions of Alkenes and Alkynes Hydrogenation Propene Propane Dehydrogenation   Ethane Ethene Polymerization Small molecules are joined together to form a large molecule Polyethylene

Reactions of Alkenes and Alkynes Combustion   Propane Halogenation 1-Pentene 1-2-dibromopentene Substitution  

Aromatic Hydrocarbons Cyclic unsaturated hydrocarbons with delocalized electrons The simplest aromatic hydrocarbon is benzene (C6H6) OR…

Geometric Isomerism in Aromatics ortho (o-) = two adjacent substituents o-dichlorobenzene meta (m-) = one carbon between substituents m-dichlorobenzene para (p-) = two carbons between substituents p-dichlorobenzene

Hydrocarbon Derivatives Class Functional Group General Formula Alcohol hydroxyl group -O — H R – OH Alkyl halide — X R — X Ether — O — R — O — R’ Aldehyde carbonyl group O || — C — H O R — C — H Ketone — C — R — C — R’ Carboxylic acid carboxyl group O — C — OH Ester — C — O— R — C — O — R’ Amine amine group | —N— R’ R — N — R’’

Alcohols -OH group Higher than expected boiling point (based on molecular weight) Naming is based on longest carbon chain attached to –OH group End in -ol

Aldehydes & Ketones -al -one No numbers used for naming aldehydes since group is always on terminal carbon

Carboxylic Acids & Esters Carboxylic acids are weak acids Examples: acetic, salicylic Esters have a fragrant, often pleasant odor Esterification:

Amines (-NH2) Derivatives of ammonia where one or more N-H bond is replaced by N-C bond Figure 22.18 shows the structures of the 20 amino acids