220 likes | 609 Views
Root of the name. This depends on the number of carbon atoms in the longest unbroken chain.1 carbon chain . Meth-2 carbon chain . Eth-3 carbon chain . Prop-4 carbon chain . But-5 carbon chain . Pent-. The default". This is a hydrocarbon that contains only single bonds. It has the suffix (
E N D
1. “Organic compounds and Nomenclature”
2. Root of the name This depends on the number of carbon atoms in the longest unbroken chain.
1 carbon chain …. Meth-
2 carbon chain …. Eth-
3 carbon chain …. Prop-
4 carbon chain …. But-
5 carbon chain …. Pent-
3. The “default” This is a hydrocarbon that contains only single bonds. It has the suffix (ending) –ane
Example
A three carbon chain with only carbons, hydrogens and single bonds is called propane. CH3CH2CH3
4. Unsaturation If a molecule contains double or triple bonds it is said to be unsaturated (meaning that it would be possible to fit in more hydrogens if the double bonds were changed to single).
Chains with one double bond take the suffix -ene. Example: ethene CH2=CH2
Chains with one triple bond take the suffix –yne. Example: Ethyne CH?CH
5. Functional Groups Most organic chemistry involves substituents
often contain the elements O, N, S, or P
also called “functional groups”- they are the chemically functional part of the molecule, and are the non-hydrocarbon part
6. Functional Groups Functional group - a specific arrangement of atoms in an organic compound, that is capable of characteristic chemical reactions.
What is the best way to classify organic compounds? By their functional groups.
7. Functional Groups The symbol “R” is used to represent any carbon chains or rings
These are called alkyl groups
CH3 - methyl group
CH3CH2 - ethyl group
CH3CH2CH2 - propyl group
8. Halogen Substituents Halogenocarbons - class of organic compounds containing covalently bonded fluorine, chlorine, bromine, or iodine
General formula: R-X
Naming? Name parent as normal, add the halogen as a substituent (or prefix) -
9. Halogen Substituents The more highly halogenated the compound is (I.e. the more greater the number of halogen atoms), the higher the b.p.
Few halogenoalkanes are found in nature….
but, readily prepared and used
halothane and also the hydrofluorocarbons
10. Alcohols and Ethers OBJECTIVES:
Describe the structures and naming of alcohols and ethers.
11. Alcohols Alcohols - a class of organic compounds with an -OH group
The -OH functional group in alcohols is called a “hydroxyl” group; thus R-OH can represent the formula, where “R” is an alkyl group
How is this different from the hydroxide ion? (covalently bonded to the carbon- not ionically as in hydroxides)
12. Alcohols Both systematic and common names
systematic:
drop the -ane ending of the parent alkane name; add ending of -anol, number the position of –OH if needed
parent is the longest chain that contains the carbon with the attached hydroxyl.
13. Alcohols The hydroxyl group is given the lowest position number
Alcohols containing 2, 3, and 4 of the -OH substituents are named diols, triols, and tetrols respectively (not needed fro year 10)
14. Alcohols Common names:
similar to halogenoalkanes, meaning name the alkyl group root followed by the suffix -anol
One carbon alcohol = meth- anol = methanol
15. Properties of Alcohols Glycerol (propan 1,2,3 triol) - used as a moistening agent in cosmetics, foods, and drugs; also a component of fats and oils
Ethyl alcohol (ethanol) used in the intoxicating beverages; an important industrial solvent
16. Ethers A class of organic compounds in which oxygen is bonded to 2 carbon chains: R-O-R is the formula
Nomenclature: The larger of the two R groups is the root and the other R group is prefixed as alkoxy-
Example:
CH3CH2OCH3 methoxyethane
17. Alkanals and Alkanones The C=O group is called the “carbonyl group”
it is the functional group in both alkanals and alkanones
Alkanals - carbonyl group always joined to at least one hydrogen (meaning it is always at the end!)
18. Alkanones Alkanones - the carbon of the carbonyl group is joined to two other carbons (meaning it is never on the end)
19. Alkanals and alkanones Nomenclature
Alkanals: identify longest chain containing the carbonyl group, then the -ane ending replaced by -anal, such as methanal, ethanal, etc.
Alkanones: longest chain with the carbonyl, then new ending of -anone; number it
propanone, 2-pentanone, 3-pentanone
20. Aldehydes and Ketones Propanone (common: acetone) is a good solvent; miscible with water in all proportions
why is it a good substance used in nail-polish removers? (a powerful solvent-able to dissolve both polar & non-polar substances)
21. Carboxylic Acids Also have a carbonyl group (C=O), but is also attached to a hydroxyl group (-OH) = “carboxyl” group
general formula: R-COOH
weak acids (only slightly dissociate into ions)
Named by replacing -ane with -anoic and followed by the word acid
methanoic acid; ethanoic acid
22. Carboxylic Acids Abundant and widely distributed in nature, many having a Greek or Latin word describing their origin
acetic acid (ethanoic acid) from acetum, meaning vinegar
many that were isolated from fats are called fatty acids