Transcript Organic - Chemistry Geek
Brief! Organic Chemistry for AP
Alkanes
• Hydrocarbon chains where all the bonds between carbons are SINGLE bonds • Name uses the ending – ane • Examples: Meth
ane
, Prop
ane
, But
ane
, Oct
ane
, 2-methylpent
ane
2 3 4 5 1
Prefixes for # of Carbons
Meth 6 Hex Eth Prop But Pent 7 8 Hept Oct 9 Non 10 Dec
Endings
• Alkanes (all C-C single bonded parent chain) end in –ane – Meth
ane
CH 4 – Eth
ane
– Prop
ane
C 2 H 6 C 3 H 8 • Attached carbon groups (substituents) end in
–yl
– Meth
yl
CH 3 – Eth
yl
– Prop
yl
CH 3 CH 2 CH 3 CH 2 CH 2 – 3-ethyl pentane
Names of attached groups
• Carbon (alk yl ) groups – Meth
yl
CH 3 – Eth
yl
– Prop
yl
CH 3 CH 2 CH 3 CH 2 CH 2 – • Halogens – Fluoro (F-) – Chloro (Cl-) – Bromo (Br-) – Iodo (I-)
Designate the Location
• Designate the location (number of the carbon on the parent chain) for each attached group 2-methyl 1 2 3 4 5
Some Simple Alkanes
• 2-methylpentane • 3-ethylhexane • 2,2-dimethylbutane • 2,3-dimethylbutane
Structural Formulas
• “Lazy” way to write the Hydrogens • Instead of drawing the bonds, just state how many hydrogens are attached • NOTE: The bonds are between CARBONS in a parent chain, and not hydrogens!
Structural Formula Lewis Structure
Drawing and Naming Cycloalkanes Cycloalkanes are represented by polygons.
A triangle represents cyclopropane, a square represents cyclobutane, a pentagon represents cyclopentane, and so on.
Isomers • Straight 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: molecular structures.
Compounds formula but with same different
• However, carbons in butane (C row (linear alkane) or are two isomers for butane.
a 4 H 10 ) can be arranged in two ways; four carbons in a branching (branched alkane). These two structures
•Different isomers are physiological properties.
completely different compounds.
They have different structures, different physical properties such as melting point and boiling point, and may have different
Learning Check
• Draw all possible structural isomers of C 5 H 12
Alkenes and Alkynes
• • • Unsaturated – contain carbon-carbon double and triple bond to which more hydrogen atoms can be added.
Alkenes: carbon-carbon double bonds Alkynes: carbon-carbon triple bonds.
Naming 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.
1 2 3 4 CH 2 =CHCH 2 CH 3 1-butene CH 3 CH=CHCH 3 CH 3 C
CCH 3 2-butene 2-butyne
Aromatic Compounds and Benzene
Aromatic compounds contain benzene.
Benzene, C 6 H 6 , is represented as a six carbon ring with 3 double bonds.
H
Two possible resonance structures can be drawn to show benzene in this form.
H H H H H H H H H H H