2AlkanesHydrocarbon chains where all the bonds between carbons are SINGLE bondsName uses the ending –aneExamples: Methane, Propane, Butane, Octane, 2-methylpentane
3Prefixes for # of Carbons 1Meth6Hex2Eth7Hept3Prop8Oct4But9Non5Pent10Dec
4Endings Alkanes (all C-C single bonded parent chain) end in –ane Methane CH4Ethane C2H6Propane C3H8Attached carbon groups (substituents) end in –ylMethyl CH3 -Ethyl CH3CH2-Propyl CH3CH2CH2 – 3-ethylpentane
5Names of attached groups Carbon (alkyl) groupsMethyl CH3 -Ethyl CH3CH2-Propyl CH3CH2CH2 –HalogensFluoro (F-)Chloro (Cl-)Bromo (Br-)Iodo (I-)
6Designate the Location Designate the location (number of the carbon on the parent chain) for each attached group2-methyl
8Structural Formulas “Lazy” way to write the Hydrogens Instead of drawing the bonds, just state how many hydrogens are attachedNOTE: The bonds are between CARBONS in a parent chain, and not hydrogens!Structural FormulaLewis Structure
9Drawing and Naming Cycloalkanes Cycloalkanes are represented by polygons. A triangle represents cyclopropane, a square represents cyclobutane, a pentagon represents cyclopentane, and so on.
10IsomersStraight chain alkanes: An alkane that has all its carbons connected in a row.Branched chain alkanes: An alkane that has a branching connection of carbons.Isomers: Compounds with same molecular formula but different structures.
11However, carbons in butane (C4H10) can be arranged in two ways; four carbons in a row (linear alkane) or a branching (branched alkane). These two structures are two isomers for butane.
12Different isomers are completely different compounds Different isomers are completely different compounds. They have different structures, different physical properties such as melting point and boiling point, and may have different physiological properties.
13Learning CheckDraw all possible structural isomers of C5H12
14Alkenes and Alkynes Unsaturated Alkenes: carbon-carbon double bonds contain carbon-carbon double and triple bond to which more hydrogen atoms can be added.Alkenes: carbon-carbon double bondsAlkynes: carbon-carbon triple bonds.
15Naming Alkenes and Alkynes When the carbon chain has 4 or more C atoms, number the chain to give the lowest number to the double or triple bond.CH2=CHCH2CH3 1-buteneCH3CH=CHCH3 2-butene CH3CCCH3 2-butyne
16Aromatic Compounds and Benzene Aromatic compounds contain benzene.Benzene, C6H6 , is represented as a six carbon ring with 3 double bonds.Two possible resonance structures can be drawn to show benzene in this form.