organic nomenclature alkanes swbat: name alkanes with alkyl groups
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Organic NomenclatureAlkanesSWBAT: Name alkanes with alkyl groups
Organic Chemistry The study of the structure,
properties, composition, reactions, and preparation (synthesis) of carbon-based compounds, hydrocarbons and their derivatives
Organic Molecules Organic molecules are compounds
consisting of nonmetals (hydrogen, nitrogen, oxygen, the halogens, phosphorus, silicon and sulfur) with carbon
Due to carbon’s hybrid bonding orbitals, organic molecules have a variety of configurations
The types of atoms bonded to the carbon atoms will ultimately determine function and properties of the compound
Organic vs. InorganicGeneral Comparison
Organic Compounds
Mostly covalent bonding
Low boiling pt Low melting pt High flammability Most are nonpolar Not soluble in water
unless a polar group is present
Do not conduct electricity
Inorganic Compounds
Many ionic, some covalent
High boiling pt High melting pt Low flammability Most are ionic or
polar covalent Most are soluble in
water unless nonpolar
Conduct electricity
Hydrocarbons A hydrocarbon chain is a series of
carbons bonded together with numerous hydrogen's attached
Includes Alkanes, Alkenes, Alkynes and Cyclical HC
Use certain prefixes for naming to indicate chain length
Alkane Formulas and Names Strings, branches of carbons with
single bonds between C Essentially many CH4 reacted
together Formula rules: CnHn+2 CH2 – methylene unit Names: Prefixes indicate # of C
followed by -ane
Homologous series of the first 12 linear alkanes Methane (meth=1) CH4 Ethane (eth =2) C2H6 Propane (prop=3) C3H8 Butane (but=4) C4H10
Pentane (pent=5) C5H12 Hexane (hex=6) C6H14 Heptane (hept=7) C7H16 Octane (oct=8) C8H18 Nonane (non=9) C9H20 Decane (dec=10) C10H22 Undecane (undec = 11) C11H24 Dodecane (dodec= 12) C12H26
1-10 Alkane Prefix QuizJust the prefix…not the -ane
1.CH4
2.C2H6
3.C3H8
4.C4H10 5.C5H12
6.C6H14 7.C7H16
8.C8H18 9.C9H20 10.C10H22
Mnemonic for First 8 Prefixes Mrs. Edwards Plays Basketball,
Please Hold Her Overcoat Methane CH4
Ethane C2H6
Propane C3H8
Butane C4H10
Pentane C5H12 Hexane C6H14
Heptane C7H16
Octane C8H18
Alkane Naming and Drawing1. Expanded structure
1. Make string of carbons (prefix= # of C)
Ex: Butane (but=4)
Butane2. Condensed structure A
CH3-CH2-CH2-CH3
3. Condensed structure BCH3CH2CH2CH3
4. Condensed structure CCH3(CH2)2CH3
Butane5. Carbon skeleton: C-C-C-C
*all H are understood
6. Kekulé or Line-angle formula(most reduced form)
• Each endpoint, every corner symbolizes a C
• H are understood
Alkanes
methane
CH4
hexane
C6H14
ethane
C2H6
heptane
C7H16
propane
C3H8
octane
C8H18
butane C4H10
nonane
C9H20
pentane
C5H12
decane
C10H22
Alkyl Groups Substituent – element or group of
elements that branch off parent chain (replace a H)
methyl group
ethyl group
propyl group
Alkyl Groups isopropyl
butyl groups butyl secbutyl tertbutyl isobutyl
Only iso- is alphabetized,tert, sec are not.
Haloalkanes Haloalkanes have a halogen that has
replaced a hydrogen The halogens are substituent groups
treated the same as the alkyl groups. Alpha without prefixes
F = fluoroCl = chloroBr = bromoI = iodo
Rules to Naming Hydrocarbon Chains
1. Number the longest continuous chain of carbons
1. Carbons attached to double/triple bonds receive the smallest number possible
2. If no double/triple bonds are present, carbons with groups attached, receive the smallest number possible
2. Use prefixes for repeating groupsdi, tri, tetra, penta, hexa, ….
3. Alphabetize groups without prefixes4. All lowercase, commas between numbers,
dashes between numbers and words5. Use appropriate ending
ane, ene, yne or functional group ending
Find The Longest Continuous Chain of Carbons
Number the Carbons so that the groups receive the smallest number possible
Use prefixes with same multiple substituent groups
7 – ethyl – 3,5 - dimethyl – 6 - tertbutylundecane
Naming Hydrocarbon Chains
Naming Hydrocarbon Chains
Naming Hydrocarbon Chains
If more than one type of substituent group, alpha. the groups without prefixes
5 – secbutyl - 3,6 – dimethylnonane
4 – tertbutyl - 5 - ethylnonane
Cycloalkanes1. Start at noon and go clockwise until you get to first carbon with a substituent group this is # 12. Go clockwise or counterclockwise so substituent groups receive the smallest number possible
Cyclical Alkaneshave 2 H less from ring closure
cyclopropane
C3H6 cyclooctaneC8H16
cyclobutane
C4H8
cyclononane
C9H18
Alkanes
cyclodecaneC10H20
cycloundecaneC11H22
cyclododecaneC12H24
Practice
1,1-dimethylcyclopentane
methylcyclopentane
Practice
1,3-dimethylcyclopentane
1,2-dimethylcyclopentane
Practice
2-ethyl,1-methylcyclohexane
Practice
2-cyclopropyl-4-ethyl-1-methylcyclohexane