simple organic chemistry
DESCRIPTION
Simple Organic Chemistry. Basic Structure and Nomenclature. Graphic: www.lab-initio.com. First Ten Alkanes. 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. - PowerPoint PPT PresentationTRANSCRIPT
Simple Organic ChemistrySimple Organic ChemistryBasic Structure and Basic Structure and
NomenclatureNomenclature
Graphic: www.lab-initio.com
First Ten AlkanesFirst Ten AlkanesFormula
Name 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
Straight Chain Alkanes aren’t Straight Chain Alkanes aren’t “Straight”“Straight”
CH3
CH3
C – C bonds are sp3 hybridized
Butane, C4H10
Structural ShorthandStructural Shorthand
H
HH
H
HH
H
H
HH
Explicit hydrogens (those required to complete carbon’s valence) are usually left off of drawings of hydrocarbons
CH3
CH3
Line intersections represent carbon atoms
C1 C1C2 C2
C3 C3C4 C4
Structural Structural IsomersIsomers
CH3
CH3
CH3
CH3 CH3
CH3
CH3
Isomers are molecules with the same chemical formula, but different organization of atoms (different bonding)
n-Pentane, C5H12
Isopentane, C5H12
Neopentane, C5H12
CH3 CH3
Newman ProjectionsNewman Projections
A Eclipsed
E
Degrees of Rotation 30060 120 180 2400 360
B Staggered
HH
HH
HH
H
HH
H
H H
Ethane, C2H6
Rotation can occur around C – C single bonds
Newman Newman ProjectionsProjections
Butane, C4H10 CH3
CH3
Cyclic AlkanesCyclic AlkanesCyclopropane, C3H6
Remember, explicit hydrogens are left out
Cyclobutane, C4H8
Cyclopentane, C5H10
Cyclohexane, C6H12
Cycloheptane, C7H14
Rules for Naming Alkanes Rules for Naming Alkanes (Nomenclature)(Nomenclature)
For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon
CH3
CH3
CH3
12 3
4
44 carbon chain = butane carbon chain = butane
Rules for Naming Alkanes Rules for Naming Alkanes (Nomenclature)(Nomenclature)
When alkane groups appear as substituents, theyare named by dropping the -ane and adding -yl.
CH3
CH3
CH3
—CH3 Methyl
—CH2CH3 Ethyl
—CH2CH2CH3 Propyl—CH2CH2CH2CH3 Butyl
Methyl
Rules for Naming Alkanes Rules for Naming Alkanes (Nomenclature)(Nomenclature)
The positions of substituent groups are specifiedby numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching.
CH3
CH3
CH3
Methyl
12 3
4
Rules for Naming Alkanes Rules for Naming Alkanes (Nomenclature)(Nomenclature)
The location and name of each substituent arefollowed by the root alkane name. The substituentsare listed in alphabetical order (irrespective of anyprefix), and the prefixes di-, tri-, etc. are used toindicate multiple identical substituents.
CH3
CH3
CH3
Methyl
12 3
4 Name:2-methylbutane
Nomenclature PracticeNomenclature Practice
CH3 CH3
CH3
CH3
Cl
Name this compound
Step #1: For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon
152 43
9
6
87
9 carbons = nonane
Nomenclature PracticeNomenclature PracticeName this compound
CH3 CH3
CH3
CH3
Cl
152 43
9
6
87
9 carbons = nonane
Step #2: When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl.
CH3 = methyl
chlorine = chloro
Nomenclature PracticeNomenclature PracticeName this compound
CH3 CH3
CH3
CH3
Cl
152 43
9
6
87
9 carbons = nonane
CH3 = 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.
1 9 NOT 9 1
Nomenclature PracticeNomenclature PracticeName this compound
CH3 CH3
CH3
CH3
Cl
152 43
9
6
87
9 carbons = nonane
CH3 = 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
Alkenes Contain Carbon-Alkenes Contain Carbon-CarbonCarbon
Double bondsDouble bonds
C C
H
H
H
H
Ethene
CC
H
H
H
H
1 bond
1 bond
Alkynes Contain Carbon-Alkynes Contain Carbon-CarbonCarbon
Triple BondsTriple Bonds
C C HH
CC HH
Ethyne
1 bond
1 bond
1 bond
Reactions of Alkenes and Reactions of Alkenes and AlkynesAlkynes
HydrogenationHydrogenation
323232 CHCHCHHCHCHCH Catalyst Propene Propane
HalogenationHalogenation
1-Pentene 1-2-dibromopentene322223222 CHCHBrCHBrCHCHBrCHCHCHCHCH
PolymerizationPolymerization
Small molecules are joined together to form a large molecule
nCH2 CH2
Polyethylene
Aromatic Aromatic HydrocarbonsHydrocarbons
H
H
H
H
H
H
Cyclic unsaturated hydrocarbons with
delocalized electronsThe simplest aromatic hydrocarbon
isbenzene (C6H6)
H
H
H
H
H
H
OR…H
H
H
H
H
H
Geometric Isomerism in Geometric Isomerism in AromaticsAromatics
Cl
Cl
H
H
H
H
Cl
Cl
H
H
H
H
ortho (o-) = two adjacent substituents
meta (m-) = one carbon between substituents
para (p-) = two carbons between substituents
pp--dichlorobenzenedichlorobenzene
oo-dichlorobenzene-dichlorobenzene
mm-dichlorobenzene-dichlorobenzene
Cl
HH
H
Cl
H
Hydrocarbon DerivativesHydrocarbon DerivativesClass 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 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’’