Chapter 22 Organic Chemistry Chapter 6 in rxn

Chapter 22 Organic Chemistry!!!!! Chapter 6 in rxn workbook Chapter 16 in PR 1

Organic Chemistry Is…. . n The study of carbon containing compounds and their properties n Organic compounds are typically in chains or rings n All organic molecules are produced by living things/systems 2

Vocabulary n Chain n Parent chain and substituent 3

The Name Game …again n Alkanes = hydrocarbons (chains of C and H) n All bonds are single i. e “Saturated” n An alkane is a hydrocarbon in which each carbon atom is bonded to four other carbon or hydrogen atoms. 4

10 “normal” alkanes 5

The Rest Pentane C 5 H 12 Hexane C 6 H 14 Heptane C 7 H 16 Octane C 8 H 18 Nonane C 9 H 20 Decane C 10 H 22 A note on Boiling Point: BP Octane C 8 H 18 < Nonane C 9 H 20 More C = more bonds to break and more energy required. 6

Isomers n Same number and type of molecules but bonded in a different location 7

Draw all isomers Pentane 1 2 3 4 5 8

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IUPAC International Union of Pure and Applied Chemistry 10

Rules for Naming Alkanes n Read Page 1061 n For chain alkanes beyond butane add the suffix –ane to the Greek root for the number of carbons 11

For Branched alkanes find the longest continuous carbon chain and use this name as the base (a). If two chains of equal length are present, choose the one with the more branch points as the parent. 12

n When alkane groups appear as substituent groups they are named by dropping the -ane and adding –yl. n For example CH 3 (methane) = methyl. C 3 H 7 is called propyl 13

n The position of substituent groups are specified by numbering the longest chain of carbon atoms sequentially starting at the end with the closest branching. C C-C-C-C 1 2 3 4 5 6 correct numbering 6 5 4 3 2 1 incorrect numbering 14

Last rule! n The location and name of each substituent is followed by the root alkane name. n Substituents are listed in alphabetical order and the prefixes (di, tri, ) are used to indicate multiple identical substituents. n A number denotes which carbon that substituent is boned to. 15

Example CH 3 – CH 2 - CH 3 1 2 3 4 5 6 3 - methylhexane Smallest number for substituent Substituent name Parent chain root name Hyphen between number and substituent name 16

Try some n Draw all structural isomers or C 6 H 14 1. Start with the longest chain and then rearrange the carbons to form the shorter CH 3 -CH 2 –CH 2 -CH 3 1 2 3 4 5 6 Hexane 17

Take one carbon out of the chain and make it a methyl substituent CH 3 -CH 2 –CH 3 2 - methylpetane 1 2 3 4 5 CH 3 -CH –CH 2 -CH 2 –CH 3 3 - methylpetane 18

Next take two carbons out of the chain CH 3 -C –CH -CH 3 2, 2 -dimethylbutane CH 3 1 2 3 4 CH 3 -CH –CH -CH 3 2, 3 -dimethylbutane 1 2 3 4 19

Write the structure for each of the following compounds n 4 -ethyl-3, 5 -dimethylnonane (note the substituents are in alphabetical order separated by a dashed line) n 4 -tert-butylheptane n (see your cheat sheet for tert structure) 20

4 -ethyl-3, 5 -dimethylnonane 1 4 9 21

4 -tert-butylheptane 1 2 3 4 5 6 7 CH 3 -CH 2 -CH-CH 2 - CH 3 H 3 C-C-CH 3 CH 3 22

Reactions of Alkanes n Combustion reaction n Substitution reactions n Dehydration reactions n page 1065 23

Cyclic Alkanes Add Cyclo to the number of carbons present 24

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Naming cyclic structures with substituent n Give substituent the lowest number possible (can start with one this time) n If more than one substituent is present number in alphabetical order insuring that all substituents have the lowest possible number 26

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Homework Read Page 1066 sample exercise 22. 4 naming cyclic alkanes Do page 1100 #’s: 15, 17, 19, 20, 28

22. 2 Alkenes and alkynes n Hydrocarbons that contain carbon double bonds. C 2 H 4 C 2 H 2 29

Rules for naming Alkenes n Root hydrocarbon chain ends in –ene methene Ethene Propene butene 30

n In alkenes with more than three carbons, the location of the double bond is indicated by the lowest numbered carbon atom INVOLVED in the double bond. CH 2= CHCH 2 CH 3 1 -butene CH 3 CH=CHCH 3 2 -butene 31

Double Bonding σ sigma bond π Pi bond 32

Isomers of Alkenes Cis: H on The same side of The molecule Trans: H on opposite sides of the molecule 33

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Practice naming Find the longest chain and number it in the direction that gives the double bond the lowest number. Identify if the molecule is cis or trans 4 -methyl-cis-2 -hexene 35

Alkynes n Unsaturated hydrocarbons containing a carbon-carbon triple bond. n The simplest alkyne is C 2 H 2 called acetylyne n In a triple bond there is one sigma bond and two pi bonds. n Replace the –ane ending –yne n Alkenes and alkynes can exist as ringed structures as well. 36

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2 -methyl-3 -heptyne Due to the triple bond there is no H to be cis or trans 38

Homework n Pg 1101 #’s : 21, 22, 23, 24 39

Aromatic Hydrocarbons n A special class of cyclic unsaturated hydrocarbons. n The simplest is benzene C 6 H 6 40

Resonance of Benzene 41

Nomenclature n If there is more than one substituent numbers are used to indicate position. 1, 2, 4 -trichlorobenzene 2, 4, 6 -trinitrotoluene (TNT) 42

FYI Toluene or Methylbenzene Common name IUPAC name 43

n Some systems use prefixes for substituent position. n Ortho (o) for two adjacent substituent meta (m) two substituent with 1 carbon between them. para (p) two substituents opposite of each other When benzene is used as a substituent it is called a phenyl group. 44

0 -dichlorobenzene m-dichlorobenzene p-dichlorobenzene 45

Give substituents lowest number and place in alpha order. o-bromochlorobenzene p-bromochlorobenzene 46

Complex aromatics pg 1072 table 22. 3 Naphthalene Anthracene Phenanthrene 47

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Homework n 25, 27(skip d) , 28, 29, 37, 38 49

22. 5 hydrocarbon Derivatives n Molecules that are fundamentally hydrocarbons (C&H) but have additional atoms or groups of atoms called functional groups n Functional Group: functional groups are specific groups of atoms with in molecules, that are responsible for the characteristics of those molecules 50

Common functional groups pg 1077 table 22. 5 Class General Formula n Halohydrocarbons R X (x = F, Cl, Br, I) n Alcohols R OH n Ethers R O R n Aldehydes R and R’ = hydrocarbon fragments 51

The Common Functional Groups Class Ketones Carboxylic Acids Esters Amines General Formula R NH 2 52

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Alcohols n Have a hydroxyl group n Replace final -e with –ol n Position of –OH group is specified with a number (smallest number goes to substituent) n Classified according to how many hydrocarbon fragments (R) they have 54

See table 22. 6 for common alcohols 55

Example: Name and state 1º, 2º, 3º n Number the chain Giving OH smallest number Note carbon that –OH is attached to has –CH 3 and a -CH 2 CH 3 groups attached. Thus it is a secondary alcohol. 56

Name and state 1º, 2º, 3º 57

3 -chloro-1 -propanol Primary alcohol 58

Phenol 59

Aldehydes and Ketones n Aldehydes and ketones contain carbonyl groups. 60

Ketones n Carbonyl group bonded two carbons atoms n Ex: acetone 61

Aldehydes Carbonyl group is bonded to at least one hydrogen 62

Naming Aldehydes and Ketones n Aldehydes: Named from parent alkane and removing the e and adding –al. n Ketones: The final e is replaced with –one. n In both cases a number indicates the position of the carbonyl group where necessary. n Note: since aldehyde functional group is always a the end of the carbon chain the aldehyde carbon is always assigned as number 1 for referencing the substituent position in the name. 63

Naming Aldehydes and Ketones n The parent chain selected must contain the carbonyl group. n Number the carbon chain, beginning at the end nearest to the carbonyl group. n Number the substituents and write the name, listing substituents alphabetically. 64

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Carboxylic Acids n Carboxylic Acids have a carboxyl group. RCOOH 67

Naming carboxylic acids n Name from parent alkane by dropping e and adding -oic 68

Esters n Carboxylic acid reacting with an alcohol to form an ester. n Sweet fruity smell (bananas, oranges) Acetylsalicylic acid 69

Amines n Have one carbon nitrogen bond. N-C n 1° one N-C bond n 2° two N-C bond n 3° three N-C bond n Common names are often used rather than IUPAC names. n Fish like odor 70

methyl amine propyl amine cyclobutyl amine 71

Homework n Pg 1102 -1103 n #’s: 41, 47, 49, 50 72