funções e nomenclatura - moodle usp: e-disciplinas

Funções e nomenclatura

• Generalidades

• Nomenclatura

http://www.chem.uiuc.edu/GenChemReferences/nomenclature_rules.html

http://www.chem.uiuc.edu/GenChemReferences/nomenclature_rules.html

Funções orgânicas• Hidrocarbonetos

• Saturados: CnH2n+2

• Insaturados: CnH2n CnH2n-2

• Lineares ou Cíclicos

• Haletos de alquila: R-X

• Álcoois: R-OH

• Éteres: R1-O-R2

• Aminas: R-NH2 R1-NH-R2 R1-N(R3)-R2

• Aromáticos: Ph-R

• Fenóis: Ph-OH

Grupo funcional Prefixo Sufíxo

ácidos carboxílicos nenhum Ácido -óico

aldeídos nenhum -al

cetonas nenhum -ona

álcoois hidróxi- -ol

aminas amino- -amina

éteres alcóxi- -éter

fluoreto fluoro- nenhum

cloreto cloro- nenhum

brometo bromo- nenhum

iodeto iodo- nenhum

Haletos de alquila

Chapter 6

A. Nomenclatura

1. IUPAC (International Union of Pure and Applied Chemistry)Acrescente: fluoro-cloro-bromo-iodo-

Ao nome do alcano

exemplos:

CH3 CH

CH3

CH

Cl

CH2CH3

2-methyl-3-chlorohexane

I

Br

trans-1-bromo-3-iodocyclobutane2-metil-3-cloro-hexano

trans-1-bromo-3-iodociclobutano

Nomenclatura IUPAC

• Name as haloalkane.

• Choose the longest carbon chain, even if the halogen is not bonded to any of those C’s.

• Use lowest possible numbers for position.

CH3 CH CH2CH3

Cl CH3(CH2)2CH(CH2)2CH3

CH2CH2Br

2-chlorobutane 4-(2-bromoethyl)heptane

9

2. Nomes usuais

CH3Cl

CH Cl

CH3

CH3

CH3CH2Cl

CH2Cl2

CHCl3

CCl4

methyl chloride

ethyl chloride

i-propyl chloride

methylene chloride

chloroform

carbon tetrachloride

3. Nomes especiais

C

X

X

C C

X X

geminal dihalide

vicinal dihalide

Cloreto de metila

Cloreto de etila

Cloreto de iso-propila

Cloreto de metileno

Clorofórmio

Tetracloreto de carbono

Usos dos haletos de alquila

• Solventes – desengraxantes e líquido para lavagem a seco

• Reagentes para síntese de outros compostos

• Anestésicos: Halotano é CF3CHClBr– CHCl3 (usado antigamente, é tóxico e carcinogênico)

• Freons, chlorofluorocarbons or CFC’s– Freon 12, CF2Cl2, now replaced with Freon 22, CF2CHCl, not

as harmful to ozone layer.

• Praguicidas - DDT banned in U.S. (1972) and Sweden (1970).

=>

B. Industrial usesa. solvents: CH2Cl2, CHCl3, CCl4b. refridgerents:

CF2Cl2 - Freon-12 (eats O3)HCF2Cl - Freon-22 (destroyed at

lower altitudes)c. pesticides: DDT •introduced 1939

•banned 1972 (Rachel Carson)

Cl C

Cl

Cl

CH

Cl

Cl

Dichlorodiphenyltrichloroethane

DDT

Chapter 6 12

chlordane -termites•banned 1995

ClCl

Cl

Cl

H

H

H H

Cl

Cl

Cl

Cl

capacitors, etc.PCB (polychlo-rinated biphenyl)•banned 1985

ClCl

Cl

Cl Cl Cl Cl

ClCl

Cl

Chapter 6 13

d. AnestheticsCHCl3 - chloroform carcinogenicCH3CH2Cl - ethyl chloride topical useCF3CHBr-Cl - halothane - general

e. polymers

H

H

Cl

H

F

F

F

F

* C

H

H

C

Cl

H

C

H

H

C

Cl

H

*

* C

F

F

C

F

F

C

F

F

C

F

F

*

polyvinyl chloride(PVC)

teflon

Classes de Haletos• Alkyl: Halogen, X, is directly

bonded to sp3 carbon.

• Also characterized as 1o, 2o, 3o

• Vinyl: X is bonded to sp2 carbon of alkene.

• Aryl: X is bonded to sp2 carbon on benzene ring. Examples:

C

H

H

H

C

H

H

Br

alkyl halide

C C

H

H

H

Cl

vinyl halide

I

aryl halide

=>

Di-haletos

• Di-haleto geminal : two halogen atoms are bonded to the same carbon

• Di-haleto vicinal: two halogen atoms are bonded to adjacent carbons.

C

H

H

H

C

H

Br

Br

geminal dihalide

C

H

H

Br

C

H

H

Br

vicinal dihalide

=>

Systematic Common Names

• Name as alkyl halide.

• Useful only for small alkyl groups.

• Name these:

CH3 CH CH2CH3

Cl

(CH3)3CBr

CH3 CH

CH3

CH2F =>

“Trivial” Names

• CH2X2 called methylene halide.

• CHX3 is a haloform.

• CX4 is carbon tetrahalide.

• Examples: – CH2Cl2 is methylene chloride

– CHCl3 is chloroform

– CCl4 is carbon tetrachloride.

=>

• Substâncias comuns

O

O O

O

O

H3C OH C2H5 OH

Metanol Etanol

Éter

Éter etílico

Éter dietílico

Oxirano

THF

Tetra-hidrofurano

1,4-Dioxano

Nomenclatura de éteres

• Os grupos ligados ao oxigênio são listados em ordem alfabética

– Allyl ethyl ether

– Éter alil etílico

• Grupos:

– RO: groupo alcóxi

O

OMe

5-Methoxy-hept-1-ene

5-metóxi-hept-1-eno

Nomenclature of Ethers, Epoxides, and Sulfides

name as alkoxy derivatives of alkanes

CH3OCH2 CH3

methoxyethane

CH3CH2OCH2 CH3

ethoxyethane

CH3CH2OCH2CH2CH2Cl

1-chloro-3-ethoxypropane

Substitutive IUPAC Names of Ethers

name the groups attached to oxygen in alphabetical order as separate words; "ether" is the

last word

CH3OCH2 CH3

ethyl methyl ether

CH3CH2OCH2 CH3

diethyl ether

CH3CH2OCH2CH2CH2Cl

3-chloropropyl ethyl ether

Functional Class IUPAC Names of Ethers

16-5

name as alkylthio derivatives of alkanes

CH3SCH2 CH3

methylthioethane

CH3CH2SCH2 CH3

ethylthioethane

(methylthio)cyclopentane

Substitutive IUPAC Names of Sulfides

SCH3

cyclopentyl methyl sulfide

analogous to ethers, but replace “ether” as lastword in the name by “sulfide.”

CH3SCH2 CH3

ethyl methyl sulfide

CH3CH2SCH2 CH3

diethyl sulfide

Functional Class IUPAC Names of Sulfides

SCH3

Oxirane

(Ethylene oxide)

Oxetane Oxolane

(tetrahydrofuran)

Oxane

(tetrahydropyran)

1,4-Dioxane

Names of Cyclic Ethers

O O O

O

O

O

Moléculas contendo a função éter

Estricnina(produto natural)

Propanolol(fármaco)

Poliéter (polímero)

Generalidades

Nomenclatura de éteres

1,2-dimetoxietano

Nomenclatura IUPAC

CH3CHCH2CH2CH3

OCH3

1-etóxi-4-metilbenzeno

O

O

O

Oxaciclopentano (nomenclatura de substituição)

1,4-dioxaciclo-hexano (nomenclatura de substituição)

CH3CH2O CH3

2-metóxipentano

CH3OCH2CH2OCH3

éter etil metílico

Nomenclatura usual

CH3CH2OCH3

O

O

O

CH3CH2OCH2CH3éter dietílico

tetra-hidrofurano

1,4-dioxano

óxido de etilenoO

McMurry Organic Chemistry 6th edition Ch 15 (c) 2003

29

Aromatic Compounds

• Aromatic was used to described some fragrant compounds in early 19th century – Not correct: later they are grouped by chemical behavior

(unsaturated compounds that undergo substitution rather than addition)

• Current: distinguished from aliphatic compounds by electronic configuration


30

Sources of Aromatic Hydrocarbons

• From high temperature distillation of coal tar

• Heating petroleum at high temperature and pressure over a catalyst

Naming Aromatic Compounds

➢Vários nomes usuais (tolueno = metilbenzeno; anilina = aminobenzeno)

➢Benzenos monossubstituidos: nomes sistemáticos como hidrocarbonetos

derivados do benzeno

✓C6H5Br = bromobenzeno

✓C6H5NO2 = nitrobenzeno

✓C6H5CH2CH2CH3 = n-propilbenzeno


32

The Phenyl Group

• When a benzene ring is a substituent, the term phenyl is used (for C6H5 )

– You may also see “Ph” or “f” in place of “C6H5”

• “Benzyl” refers to “C6H5CH2”


33

Disubstituted Benzenes

• Relative positions on a benzene ring

– ortho- (o) on adjacent carbons (1,2)

– meta- (m) separated by one carbon (1,3)

– para- (p) separated by two carbons (1,4)

• Describes reaction patterns (“occurs at the para position”)


34


35

Naming Benzenes With More Than Two Substituents

• Choose numbers to get lowest possible values

• List substituents alphabetically with hyphenated numbers

• Common names, such as “toluene” can serve as root name (as in TNT)


36

Michael Faraday (1791-1867)

•Mais conhecido por suas descobertas sobre fenômenoselétricos. Contudo, iniciou sua carreira com estudos naárea da química.

• Isolou o benzeno do resíduo oleoso encontrado na postesde iluminação a gás das ruas de Londres e determinou quea razão C:H era de 1:1.

•O nome do grupamento fenila, usado quando uma unidade de benzeno encontra-se como um substituinte, deriva de sua origem, pois a palavra grega pheno significa“Eu tenho a luz”.

•O benzeno foi sintetizado, em 1834, por Eilhard Mitscherlich, o qual determinousua fórmula molecular como C6H6.

•Outros compostos com uma baixa razão C:H apresentavam um aroma agradável,desta maneira foram classificados como aromáticos.

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