Simple Organic Chemistry Basic Structure and Nomenclature Graphic:

First Ten Alkanes FormulaNameFormulaName CH 4 MethaneC 6 H 14 Hexane C2H6C2H6 EthaneC 7 H 16 Heptane C3H8C3H8 PropaneC 8 H 18 Octane C 4 H 10 ButaneC 9 H 20 Nonane C 5 H 12 PentaneC 10 H 22 Decane Alkane = C n H 2n+2

Straight Chain Alkanes aren’t “Straight” C – C bonds are sp 3 hybridized Butane, C 4 H 10

Structural Shorthand Explicit hydrogens (those required to complete carbon’s valence) are usually left off of drawings of hydrocarbons Line intersections represent carbon atoms C1C1 C1C1 C2C2 C2C2 C3C3 C3C3 C4C4 C4C4

Structural Isomers Isomers are molecules with the same chemical formula, but different organization of atoms (different bonding) n-Pentane, C 5 H 12 Isopentane, C 5 H 12 Neopentane, C 5 H 12

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

Rules for Naming Alkanes (Nomenclature) When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl. —CH 3 Methyl —CH 2 CH 3 Ethyl —CH 2 CH 2 CH 3 Propyl —CH 2 CH 2 CH 2 CH 3 Butyl Methyl

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

Rules for Naming Alkanes (Nomenclature) 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. Methyl Name:2-methylbutane

Nomenclature Practice Name this compound Step #1: For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon carbons = nonane

Nomenclature Practice Name this compound carbons = nonane Step #2: When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl. CH 3 = methyl chlorine = chloro

Nomenclature Practice Name this compound carbons = nonane CH 3 = methyl chlorine = chloro 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. 19 NOT 91

Nomenclature Practice Name this compound carbons = nonane CH 3 = methyl chlorine = chloro Step #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. 2-chloro-3,6-dimethylnonane

Nomenclature Practice Name this compound

Nomenclature Practice Name this compound Number the longest chain and give it a name! Determine the side groups. So there are 3 methyl and 1 ethyl side groups. Name and number the side groups! carbons = decane 10 So the name is 7-ethyl-2,3,4 trimethyldecane

Cyclic Alkanes Cyclopropane, C 3 H 6 Remember, explicit hydrogens are left out Cyclobutane, C 4 H 8 Cyclopentane, C 5 H 10 Cyclohexane, C 6 H 12 Cycloheptane, C 7 H 14

Alkenes Contain Carbon-Carbon Double bonds Ethene 1  bond 1  bond

Alkynes Contain Carbon-Carbon Triple Bonds Ethyne 1  bond 1  bond

Reactions of Alkenes and Alkynes Hydrogenation PropenePropane Halogenation 1-Pentene1-2-dibromopentene Polymerization Small molecules are joined together to form a large molecule Polyethylene

Aromatic Hydrocarbons Cyclic unsaturated hydrocarbons with delocalized electrons The simplest aromatic hydrocarbon is benzene (C 6 H 6 ) OR…

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

Hydrocarbon Derivatives ClassFunctional GroupGeneral 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 carbonyl group O || — C — O || R — C — R’ Carboxylic acid carboxyl group O || — C — OH O || — C — OH Ester O || — C — O— O || R — C — O — R’ Amine amine group | —N— R’ | R — N — R’’