Presentation is loading. Please wait.

Presentation is loading. Please wait.

Compounds in which carbon is the principal element.

Similar presentations

Presentation on theme: "Compounds in which carbon is the principal element."— Presentation transcript:

1 Compounds in which carbon is the principal element.
Organic Nomenclature Compounds in which carbon is the principal element.

2 Writing formulas. . . Condensed: CH3CH(CH3)CH = CHCH(CH3)CH3 Kekule’

3 Hydrocarbons. . . Contain only hydrogen and carbon. Types:
Alkane: single bonds; saturated (largest possible number of hydrogens/carbon atom. [CnH2n+2] Alkene: one or more carbon-carbon double bond. Unsaturated hydrocarbon. Alkyne: one carbon-carbon triple bond. Unsaturated hydrocarbon. Aromatic: carbon atoms connected in a planar ring. Unsaturated hydrocarbon.

4 Hydrocarbons. . . Relatively nonpolar. (covalent bonds)
Insoluble in water. (like dissolves like) Less volatile with increasing molar mass. (because of London dispersion forces)

5 Alkanes. . . [CnH2n+2] Methane: CH4 major component of natural gas; home heating; gas stoves; hot water heaters Ethane: C2H6 Propane: C3H8 used for home cooking and heating; gas grills Butane: C4H10 disposable lighters and fuel canisters for gas camping stoves.

6 Name consists of. . . 1. Prefix 2.Parent 3. Suffix
Where are the substituents? 2.Parent How many carbons in the longest chain? 3. Suffix Which family? If two different chains of equal length are present: choose the one with the larger number of branch points as the parent.

7 pent=5; hex=6; hept=7; oct=8; non=9; dec= 10
Rules for naming alkanes Longest continuous chain of carbon atoms gives the root name 1. For alkanes, add –ane to the root: Meth: C Eth: C2 Prop: C3 But: C4 2. For alkanes beyond butane, use the Greek root for the number of carbons then add -ane to the end. C-C-C-C-C-C = hexane pent=5; hex=6; hept=7; oct=8; non=9; dec= 10

8 Group(s) added in place of a removed hydrogen.
Substituent Group(s) added in place of a removed hydrogen.

9 Alkanes as a substituent group. . .
Alkyl substituents: 1. Remove a hydrogen from the alkane. C2H6 is ethane 2. Drop the -ane and add -yl. -C2H5 is ethyl

10 Positions of substituent groups are specified by numbering the longest chain sequentially. (Use the lowest number for the position of the substituent group) The location and name of the substituent group is followed by root alkane name. C C-C-C-C-C-C 3-methylhexane


12 Substituents in alphabetical order.
Use di-, tri-, etc. to indicate multiple identical substituents.

13 Practice. . .write skeletal and condensed formulas.
2,3-dimethylhexane 2-ethyl-3-methylpentane 4-ethyl-3,5-dimethylnonane 4-tert-butylheptane 2,3-dimethylpentane

14 Cyclic Alkanes. . . CnH2n Cycloalkanes
Smaller than five carbons, very reactive. Rings of carbon atoms. Isomers Cis: both substituents are on the same side of the ring. Trans: substituents are on opposite sides of the ring.





19 Reactions of Alkanes Combustion: react with oxygen produce carbon dioxide and water Substitution: halogen atoms replace hydrogen atoms Dehydrogenation reactions:hydrogen removed forms double bond there unsaturated hydrocarbon is the product



22 Alkenes. . . 1. Root hydrocarbon (longest chain containing double bond) name ends in –ene. 2. More than three carbon atoms, the location of the double bond is indicated by the lowest numbered carbon atom in the bond. If equidistant: begin at end closer to substituent group. CH2=CHCH2CH3 1-butene CH3CH=CHCH butene 3. More than one double bond Indicate the position of each and use –diene, triene, tetraene. . .

23 Cycloalkenes. . . Name same as alkenes.
Number so double bond is between C1 and C2 and the first substituent has the lowest number possible.

24 Practice. . .write the skeletal formula and name.

25 Practice. . . 2-methyl-1,5-hexadiene 3-ethyl-2,2dimethyl-3-heptene
2,3,3-trimethyl-1,4,6-octatriene 4-tert-butyl-2-methylheptane 3,4-diisopropyl-2,5-dimethyl-3-hexene

26 Practice. . . CH3 CH(CH3)2 CH3

27 Alkynes. . . Unsaturated hydrocarbons contain atleast one triple carbon-carbon bond. -yne replaces –ane. Begin numbering chain at end closest to triple bond. More than one bond: -diynes, -triynes. Double and triple bonds: -enynes Start numbering from end nearer first bond. (if there is a choice. Usually double bonds get lower numbers than triple.)

28 Practice. . . CH3CH(CH3)C CCH(CH3)CH3 CH CC(CH3)(CH3)CH3

29 Practice. . .

30 Reactions of Alkenes and Alkynes. . .
Addition reactions: double bond broken and new bonds formed to atoms added. Hydrogenation reactions: addition of hydrogen atoms Halogenation: addition of a halogen Elimination:one reactant splits apart to give two products. Substitutions: two reactants exchange parts to give two new products. Rearrangement:one reactant undergoes a reorganization of bonds and atoms to give a new product.

31 Aromatic Hydrocarbons. . . Benzene and its structural relatives
Monosubstituted benzene: named as other hydrocarbons, with benzene as parent name. If substituent larger than ring (six carbons) : benzene becomes substituent group called phenyl. Disubstituted benzene: ortho:1,2 meta-1,3 para-1,4 More than two: number the position of each substituent group.

32 Alcohols. . . Alcohols: presence of an –OH (hydroxyl group)
Nomenclature: replace final -e of parent hydrocarbon with –ol. (parent: longest chain containing –OH) Position of –OH specified by number- lowest number. Classified by: number of hydrocarbon fragments bonded to carbon where –OH group is attached. eg. C-C-C-C or C-C-C-C or C C-C-C

33 Functional Groups

34 Alcohols Polar Higher boiling points than expected from molecular weights. Intermolecular attractions. –OH extensive hydrogen bonding.

35 Practice. . . CH3C(OH)(CH3)CH2CH2CH3 2methyl-2-pentanol
CH3CH(OH)CH2CH(OH)CH(CH3)2 5-methyl-2,4-hexanediol

36 Practice. . .

37 Practice. . . 2-ethyl-2-buten-1-ol 3-cyclohexen-1-ol
3-chlorocycloheptanol 1,4-pentanediol

38 Aldehydes. . . Nomenclature: remove –e replace with –al.
Longest chain as base name,must contain the carbonyl group. Aldehyde carbon assigned number 1, when subtituent positions are listed in the name. Bonded to at least one hydrogen atom. Number indicates position of carbonyl group.

39 Practice. . .

40 Practice. . . CH3CHO Ethanal CH3CH2CHO Propanal
CH3CH(CH3)CH2CH(CH2CH3)CHO 2-ethyl-4-methylpentanal

41 Ketones. . . Contain carbonyl group bonded to two carbon atoms
Final –e replaced with -one. Longest chain with ketone group is the parent. Numbering begins at the end nearest the carbonyl carbon.

42 Practice. . . CH3CH=CHCH2COCH3 4-hexen-2-one CH3CH2COCH2COCH3
2,4-hexanedione CH3CH2COCH(CH3)2 2-methyl-3-pentanone CH3COCH2CH2CH2COCH2CH3 2,6-octanedione

43 Practice. . . OHCCH2CH2CH2CHO Pentanedial
CH3CH2CH(CH3)CH(CH2CH2CH3)COCH3 4-methyl-3propyl-2-hexanone CH3CH=CHCH2CH2CHO 4-hexenal

44 Practice. . . 3-methylbutanal 3-methyl-3-butenal 4-chloro-2-pentanone

45 Carboxylic Acids. . . Two systems: aldehyde and alcohol
Derived from open chain alkanes: Carboxyl carbon is always C1. Replace terminal –e of alkane with –oic acid. -COOH group bonded to a ring, the suffix –carboxylic acid is used. The carboxylic acid carbon is attached to C1 and is not itself numbered in this system.

46 Practice. . . CH3CH(CH3)CH2CH2COOH 4-methylpentanoic acid
HOOCCH2CH(CH2CH3)CH2CH2CH(CH3)CH2COOH 3-ethyl-6-methyloctanedioic acid

47 Practice. . .

48 Practice. . . (CH3)2CHCH2COOH 3-methylbutanoic acid CH3CHBrCH2CH2COOH
4-bromopentanoic acid CH3CH=CHCH=CHCOOH 2,4-hexadienoic acid CH3CH2CH(COOH)CHCH2CH2CH3 2-ethylpentanoic acid

49 Carboxylic Acids. . . Strong hydrogen bonding has a noticeable effects on boiling points. Much higher than corresponding alcohols.

50 Isomerism






Download ppt "Compounds in which carbon is the principal element."

Similar presentations

Ads by Google