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Organic ChemistryOrganic Chemistryby PVRby PVR SatishSatish KumarKumar

Organic ChemistryOrganic Chemistryby PVRby PVR SatishSatish KumarKumar

Brief Introduction toBrief Introduction to

Organic ChemistryOrganic Chemistry

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I. IntroductionDef: Chemistry of Carbon Containing Compounds

Carbon is unique since it can form single, double, & triplebonds with itself and with other atoms.

Frequently find F, Cl, Br, I, N, O, P, S atoms in carboncompounds. H always present.

Note that carbon always has 4 bonds & H 1 bond; Ousually 2; N usually 3; VIIA 1 bond.

Functional Group = portion of molecule which controls thechemistry.

There is a complexity to the organic moleculesfound in living systems that cannot beexplained by any natural process.

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I. IntroductionCan write organic structures several ways

.Example Butane: C4H10

CH3CH2CH2CH3 CH3-CH 2-CH 2-CH 3

H H H H

H C C C C H

H H H H

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I. Introduction

Isomers Different compounds with thesame formula.

Example: C 4H10 CH3

CH3CH2-CH 2-CH 3 or CH 3 CH CH 3

Are over 6 trillion isomers of C 40H84

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I. IntroductionIsomers Are three basic types

1) Structural Completely different structures

2) Geometric Differ in Geometry cis & trans

3) Stereo Differ in their 3D R & S

Examples: Butane vs 2-methylpropanecis & trans 1,2-dibromoeth ene

R & S bromochlorofluoromethane

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II. Nomenclature

Need a system that can name an infinite number ofmolecules and one that can obtain the structure fromthe name . F FAn example is 1,2-difluoro eth ene CH=CH

The name has three parts: Prefix , Base , Enda) prefix : Tells , types & where side groups attachedb) Base : Tells of Cs in longest continuous chainc) End: Tells which functional group is present

1,2-difluoro eth eneNote: numbers are separated by a comma and numbers

& letters are separated by a dash .

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II. Nomenclature - Examples

CH3-CF2-CH3 2,2-difluoropropane

CH3-CH2-CH2-OH 1-propanol

CH3-CH=CH-CH3 2-butene

CH3-CI =CH-CH3 2-iodo-2-butene

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III. Hybrid Atomic Orbitals (HAO)

sp1, sp 2, sp 3 HAO- C, N, O use HAO when form bonds.- 2s and 2p orbitals rearrange to fit the bonding situation.- When form sp 3 have all single bonds (104-109 o)

- When form sp2

have one double bond (120o

)- When form sp 1 have two double bonds (or triple) (180 o)Predicting HAO- Draw Lewis structure of organic

- Note how many double bonds & use above rulesExample - Determine HAO used by C, O & N:

CH3-CH=O CH2=C=CH2 CH3-NHCH 3sp3 sp2 sp2 sp2 sp1 sp2 sp3 sp3 sp3

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IV. Functional Groups

Alkanes - Contain all single bonds- Methane CH 4- Ethane CH 3-CH 3- Propane CH 3-CH 2-CH 3- Butane CH 3-CH 2-CH 2-CH 3- Pentane, Hexane, Heptane, Octane, etc.

Alkenes - Contain 1 or more double bonds Ethene CH 2=CH2 Propene CH 3-CH=CH3 Butene Two structural isomers

(1-butene & 2-butene)

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IV. Functional Groups

Cyclic Alkanes and AlkenesCyclopropane, Cyclobutane, Cyclopentene

Aromatics Contain Benzene, C6H

6

Uses sp 2 HAO, Flat, Carcinogen

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III. Functional Groups

OAlcohols R OH except R-C-OH

Ethers R O R

Aldehydes R CH=O

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III. Functional Groups

O

Ketones R-C-R

OCarboxylic Acids R-C-OH

OEsters R-C-OR

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III. Functional Groups

Amines R-NH 2 R-NH-R

O

Amides R-C-NH 2

Halides R-Cl Br I or F

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IV. Resonance

- Some compounds like benzene can exist in morethan one form by altering the position of thedouble bonds. We call this resonance & truestructure is combination of the resonance forms.

H

H

H

H

H

H

H

H

H

H

H

H