Organic Chemistry- introduction -

Vladimíra Kvasnicová

Composition of Matter

• inorganic mater oxygen (O) 50% silicon (Si) 25% aluminium (Al) 7% iron (Fe) 5% calcium (Ca) 3%

90%

sodium (Na) potassium (K) magnesium (Mg) hydrogen (H) titanium (Ti) 0,6%

• organic mater„compounds of carbon“

C, O, H, N

carbon (C) oxygen (O) hydrogen (H) nitrogen (N) phosphorus (P) sulfur (S)

Organic compounds

• „compounds of carbon“

• hydrocarbon skeleton: C, H (linear / branched / cyclic)

saturated: CH3-(CH2)n-CH3

unsaturated: -CH=CH- or –C=C-

• heteroatoms: O, N, S, halogens heterocyclic compounds hydrocarbon derivatives (in functional groups)

• aliphatic or aromatic compounds

Valence of elements in organic compounds

• CARBON always tetravalent

• NITROGEN trivalent

• OXYGEN bivalent

• SULPHUR bivalent

• HYDROGEN monovalent

• HALOGENS monovalent

Types of bonds:

1) single (-ane) saturated hydrocarbons

2) double (-ene) or triple (-yne)

unsaturated hydrocarbons

3) conjugated (planar cycle: arens)

Shape of molecules

σ-bond C-C

π-bond C=CC≡C

Alkanes– hybridization sp3 – tetrahedral

shape (4 bonds)

ethane

Alkenes– hybridization sp2 – trigon (3 and 1 )

Alkynes– hybridization sp – linear (2 and 2 )

ethene

ethyne

inorganic compounds organic compounds

high melting points low melting points

most inorganic compounds are soluble in water

most organic compounds are insoluble in water

not soluble in organic liquids are soluble in organic liquids

most inorganic compounds conduct an electric current

don´t conduct electricity

met- et- prop- but- pent- hex-

hept- oct- non- dec-

1 2 3 4 5 6 7 8 9 10

Chemical properties

• hydrocarbons are hydrophobic (= lipophilic) because are nonpolar

• hydrocarbon derivatives:polar functional group + nonpolar tail

• reactivity: multiple bonds

functional groups

• complete oxidation (= burning) of a hydrocarbon skeleton → CO2 + H2O

Important chemical reactions of organic compounds

1. substitution (= replacement)CH4 + Cl2 → CH3Cl + HCl

2. addition (multiplicity of chemical bond is lowered)CH2=CH2 + H2O → CH3-CH2-OH

3. elimination (new multiple bond is often formed,small molecule is

released)CH3-CH2-OH → CH2=CH2 + H2O

4. rearrangement (= formation of an isomer) CH2=C(OH)-COOH → CH3-C(O)-COOH

Hydrocarbon rests (alkyls, R)

CH4 → CH3- → -CH2-

methane methyl methylene

CH3-CH3 → CH3-CH2- → -CH2-CH2-

ethane ethyl ethylene

CH2=CH2 → CH2=CH- → -CH=CH-

ethene vinyl vinylene(„ethylene“) (ethenyl)

Aromatic compounds

• delocalization of π-elektrons

• more resonance structures

• planar molecules

• Hűckel rule: 4n + 2 = number of -electronsn = 1, 2, 3,...

Aromatic hydrocarbons (= arenes)

= = = = benzene

= naphthalene=

= = anthracene

= =

= phenanthrene

= = pyrene

= benzopyrene

Hydrocarbon rests of arenes (aryls, Ar)

→ = = =

=

benzene

phenyl

= biphenyl

CH3

→

CH2

toluene benzyl

COOH

→

CO

benzoic acid

benzoyl

Important derivatives of benzene

• methylbenzene = toluene

• dimethylbenzenes = xylenes (o-, m-, p-)1,2-dimethylbenzene = o-xylene

1,3-dimethylbenzene = m-xylene

1,4-dimethylbenzene = p-xylene

• vinylbenzene = styrene (→ polystyrene,

PS)

Exercise- add names of the compounds:

1. CH3-CH2-CH2-CH3

2. CH3-CH2-CH=CH-CH3

3. CH2=CH2

4. CH3-CH2-CH2-CH2-C=CH

5. CH3-(CH2)10-CH3

butane

pent-2-ene

ethene

hex-1-yne

dodecane

DERIVATIVES OF HYDROCARBONS

• principal functional group

type of the derivative suffix

• other functional groups

→ expressed by special prefixes +

locants

The name of the compound is derived from the name of the basic unbranched

hydrocarbon

1 2 3 4 5 6 7

meth-

eth-prop

-but- pent- hex- hept-

mono

di tri tetrapent

ahexa

hepta

8 9 10 11 12 13 20

oct- non- dec-unde

c-dode

c-tride

c-icosa

-

octa nona deca

Number of carbons / number of multiple bonds or functional

groups

derivative

formula prefix suffix

carboxylic acid

- COOH carboxy- -oic acid

sulfonic acid

- SO3H sulfo- sulfonic acid

aldehyde - CHO formyl- -al

ketone = CO oxo- -one

alcohol - OH hydroxy- -ol

thiol - SH mercapto-

-thiol

amine - NH2 amino- -amine

ether - O - R-oxy- ether

sulfide - S - R-thio- sulfide

halogen der.

- F, -Cl, -Br, -I halogen- -

nitro der. - NO2 nitro- -

derivative

formula prefix suffix

carboxylic acid

- COOH carboxy- -oic acid

sulfonic acid

- SO3H sulfo- sulfonic acid

aldehyde - CHO formyl- -al

ketone = CO oxo- -one

alcohol - OH hydroxy-

-ol

thiol - SH mercapto-

-thiol

amine - NH2 amino- -amine

ether - O - R-oxy- ether

sulfide - S - R-thio- sulfide

halogen der.

- F, -Cl, -Br, -I halogen- -

nitro der. - NO2 nitro- -

derivative

formula prefix suffix

carboxylic acid

- COOH carboxy- -oic acid

sulfonic acid

- SO3H sulfo- sulfonic acid

aldehyde - CHO formyl- -al

ketone = CO oxo- -one

alcohol - OH hydroxy- -olthiol - SH mercapto

--thiol

amine - NH2 amino- -amine

ether - O - R-oxy- ether

sulfide - S - R-thio- sulfide

halogen der.

- F, -Cl, -Br, -I halogen- -

nitro der. - NO2 nitro- -