1 / 26

Naming Hydrocarbons (nomenclature)

Naming Hydrocarbons (nomenclature). Drawing structures: it’s all good. 2-butene. On a test, choose a method that shows all Hs. This is called the “condensed structure”. CH 3 CH=CHCH 3. Using brackets can also shorten some formulas: CH 3 (CH 2 ) 4 CH 3 vs. CH 3 CH 2 CH 2 CH 2 CH 2 CH 3.

wynona
Download Presentation

Naming Hydrocarbons (nomenclature)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Naming Hydrocarbons(nomenclature)

  2. Drawing structures: it’s all good 2-butene On a test, choose a method that shows all Hs This is called the “condensed structure” CH3CH=CHCH3 Using brackets can also shorten some formulas: CH3(CH2)4CH3 vs. CH3CH2CH2CH2CH2CH3

  3. Background: formulas for HCs • Alkanes= CnH2n+2, enes= CnH2n, ynes= CnH2n-2 • Remember enes, then think of what would happen if bond was single or triple instead. • Provides some useful information (e.g. for compositional analysis, or to check work) • Cannot always tell hydrocarbon type based on numbers (e.g. propyne vs. propadiene) Q - how many hydrogens in each of these: 6 carbon alkane Alkene: C22H 14 44 8 (2x5 - 2 = 10 - 2)

  4. Formic acid Acetone Acetylene Naming: common vs. IUPAC • Common names used in the 1800’s are still used for some compounds today: • The International Union of Pure and Applied Chemistry (IUPAC) was established in 1900s • Frequent revisions to nomenclature • Systematic method allows an infinite number of compounds to be named given a few rules

  5. Basic names of hydrocarbons • Hydrocarbon names are based on: 1) class 2) # of C, 3) side chain type and 4) position • 1) name will end in -ane, -ene, or -yne • 2) the number of carbons is given by a “Prefix” 1 meth- 2 eth- 3 prop- 4 but- 5 pent- 6 hex- 7 hept- 8 oct- 9 non- 10 dec- • Actually, all end in a, but a is dropped when next to a vowel. E.g. a 6 C alkene is hexene Q - What names would be given to these: 7C, 9C alkane 2C, 4C alkyne 1C, 3C alkene heptane, nonane ethyne, butyne does not exist, propene

  6. Monkeys • Eat • Peeled • Bananas Mnemonic for first four prefixes First four prefixes • Meth- • Eth- • Prop- • But-

  7. Other prefixes • Pent- ? Decade Decimal Decathalon • Oct- • Dec- • Hex-, Hept-, Non-

  8. C2H4 Numbering carbons 1-pentene Q- draw pentene A- Where’s the bond? We number C atoms • Thus, naming compounds with multiple bonds is more complex than previously indicated • Only if 2+ possibilities exist, are #s needed • Always give double bond the lowest number • Q - Name these 2-butene Ethene 3-nonyne

  9. CH3CH2CH2CH=C=CH2 Multiple multiple bonds 2,3-heptadiene 2,4,6-nonatriyne • Give 1st bond (1st point of difference) lowest # • include di, tri, tetra, penta, etc. before ene/yne • Comma between #s, hyphen between #-letter • You do not need to know ene + yne 2-butyne 1,2,4-pentatriene 1,2-hexadiene

  10. Cyclic structures • Cyclic structures are circular • Have “cyclo” in name • Benzene is not a cyclic structure • cyclopentane Q- Draw these (note: carbons in a double bond should be consecutive- 1 and 2, 5 and 6, etc.): cyclobutene 1,3-cyclopentadiene cyclopropane

  11. C H 3 H C C H 3 3 C H 3 Naming side chains • 2,3-dimethylpentane • Names are made up of: side chains, root • Root is the longest possible HC chain • Must contain multiple bonds if present • Add -yl to get name of side chain • Common side chains include: • CH3- methyl CH3CH2- ethyl • CH3CH2CH2- propyl (CH3)2CH- isopropyl • “iso” (branched) is not an IUPAC convention • Br- (bromo), Cl- (chloro), F- (fluoro), I- (iodo)

  12. Naming side chains Example: use the rules on the bottom of handout to name the following structure Rule 1: choose the correct ending ene

  13. Naming side chains Rule 2: longest carbon chain ene

  14. Naming side chains Rule 3: attach prefix (according to # of C) 1-hexene ene

  15. Naming side chains Rule 4: Assign numbers to each carbon 1-hexene

  16. Naming side chains Rule 4: Assign numbers to each carbon 1-hexene 1-hexene

  17. Naming side chains ethyl methyl methyl Rule 5: Determine name for side chains 1-hexene 1-hexene

  18. Naming side chains ethyl methyl methyl Rule 6: attach name of branches 2-ethyl-4-methyl-4-methyl-1-hexene 1-hexene

  19. Naming side chains ethyl methyl methyl Rule 7: list alphabetically 2-ethyl-4-methyl-4-methyl-1-hexene 1-hexene

  20. Naming side chains ethyl methyl methyl Rule 8,9: group similar branches 2-ethyl-4-methyl-4-methyl-1-hexene 1-hexene

  21. Naming side chains ethyl methyl methyl Rule 8,9: group similar branches 2-ethyl-4,4-dimethyl-1-hexene

  22. Naming side chains 3-methylhexane 4-ethyl-2,3-dimethylheptane 5-ethyl-2,4,6-trimethyloctane

  23. Naming side chains Name the structures below 3-ethyl-2-methylpentane 5-ethyl-1,3,3-trimethylcyclohexene

  24. More practice 4-bromo-7-methyl-2-nonene 2,5-dibromo-6-chloro-1,3-cycloheptadiene 5-fluoro-7,7-dimethyl-2,4-octadiene

  25. Draw the following 2,2-dimethyloctane 1,3-dimethylcyclopentane 1,1-diethylcyclohexane 6-ethyl-5-isopropyl-7-methyl-1-octene

  26. Ortho Meta Para Aromatic nomenclature 1,2-dimethylbenzene orthodimethylbenzene There are 2 naming methods • Numbering carbons • ortho, meta, para (stomp) ST 1,3-dimethylbenzene metadimethylbenzene Benzene is very stable (does not generally undergo addition) 1,4-dimethylbenzene paradimethylbenzene

More Related