chapter 1 organic chemistry chemistry 20. organic compounds
TRANSCRIPT
Chapter 1
Organic Chemistry
Chemistry 20
Organic Compounds
Organic Compounds
Chemistry of Carbon (H, O, N, S, Halogens, and P).
H: 0.9%Ti: 0.6%Others: 0.9%
C one of the 116 elements
Obtained by:
Isolation from nature (animal and plant)
Synthesis in lab
Organic compounds: 10 million
Inorganic compound: 1.7 million
Compounds in living systems are organic: Biochemistry
Organic Compounds
(extract-isolate-purify)
NH4Cl AgNCO H2N-C-NH2
OAgCl+ heat +
Ammoniumchloride
Silvercyanate
Urea Silverchloride
Organic Compounds
First organic compound that is synthesized in lab.
Wöhler (1828)
Organic Compounds
Typical organic compounds:
• Contain carbon
• Have covalent bonds
• Have low melting points
• Have low boiling points
• Are flammable (all burn)
• Are soluble in nonpolar solvents
• May be gases, liquids or solids
C3H8
Propane
Organic Compounds Inorganic Compounds
Bonding is almost entirely covalentMay be gases, liquids, or solidswith low melting points (lessthan 360°C)Most are insoluble in waterMost are soluble in organic solventssuch as diethyl ether, toluene, and dichloromethaneAqueous solutions do notconduct electricityAlmost all burn
Reactions are usually slow
Most have ionic bondsMost are solids with high melting points
Many are soluble in waterAlmost all are insoluble in organic solvents
Aqueous solutions conductelectricityVery few burn
Reactions are often very fast
Organic Compounds
shows the atoms present in a molecule as well as
the bonds that connect them.
Structural Formula (Lewis Structure)
H-C-C-H
H
H H
H H
HC C
H
HH-C C-H
H-C-O-H
H
H
HC O
HH-C-N-HH
HH
HN
H HC
H-C-C-Cl
H
H H
H
Ethane(bond angles
109.5°)
Ethylene(bond angles
120°)
Acetylene(bond angles
180°)
Methanol(bond angles
109.5°)
Formaldehyde(bond angles
120°)
Methanamine(bond angles
109.5°)
Methyleneimine(bond angles 120°)
Chloroethane(bond angles
109.5°)
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VSEPR Model
VSEPR: Valence-Shell Electron-Pair Repulsion method
Bond angle: angle between two atoms bonded to a central atom.
Each region of electron likes to be as far away as possible from the others.
Regions of electron density
Four regions of electron density around an atom:
Bond Angles & Geometric Structures
Linear molecules
Trigonal planarmolecules
Tetrahedral arrangement
2 regions
3 regions
4 regions
Tetrahedral Electron Pair Geometry(Tetrahedral arrangement)
H2OCH4 NH3
Tetrahedral Electron Pair Geometry
Unshared electron paires
– Carbon: normally forms four covalent bonds and has no unshared pairs of electrons.
– Hydrogen: forms one covalent bond and no unshared pairs of electrons.
– Nitrogen: normally forms three covalent bonds and has one unshared pair of electrons.
– Oxygen: normally forms two covalent bonds and has two unshared pairs of electrons.
– A Halogen: normally forms one covalent bond and has three unshared pairs of electrons.
C
H
N
O =....
..
Cl.... ..
An atom or group of atoms within a molecule that shows a characteristic set of predictable physical and chemical properties.
– A way to classify organic compounds into families.
– They determine the chemical and physical properties of a compound.
– They undergo the same types of chemical reactions.
– A way to name organic compounds.
Functional groups
-OH
-NH2
-C-H
-C-
CH3CH2OH
CH3CH2NH2
CH3CHO
CH3CCH3
O
CH3COHO
-C-OH
Example
Alcohol
Amine
Aldehyde
Ketone
Carboxylic acid
Ethanol
Ethanamine
Ethanal
Acetone
Acetic acid
NameFamilyFunctionalgroup
CH3COCH2CH3
O-C-ORCarboxylic ester Ethyl acetate
O
O
O
O
Functional groups
• Alkanes: contain single bonds between carbon atoms.
• Alkenes: contain one or more double bonds.
• Alkynes: contain one or more triple bonds.
Alkanes, Alkenes, and Alkynes
CC
CC
CC
Alcohols and Ethers
C C
C C
O
O
H
• Alcohols: contain the hydroxyl (-OH) functional group.
• Ethers: an oxygen atom is bonded to two carbon atoms.
C O C
• Aldehydes: contain a carbonyl group (C=O), which is a carbon atom with a double bond to an oxygen atom.
• Ketones: the carbon of the carbonyl group is attached to two other carbon atoms.
Aldehydes and Ketones
O
O
CC
C
CC
-OH
-NH2
-C-H
-C-
CH3CH2OH
CH3CH2NH2
CH3CHO
CH3CCH3
O
CH3COHO
-C-OH
Example
Alcohol
Amine
Aldehyde
Ketone
Carboxylic acid
Ethanol
Ethanamine
Ethanal
Acetone
Acetic acid
NameFamilyFunctionalgroup
CH3COCH2CH3
O-C-ORCarboxylic ester Ethyl acetate
O
O
O
O
-OH
-NH2
-C-H
-C-
CH3CH2OH
CH3CH2NH2
CH3CHO
CH3CCH3
O
CH3COHO
-C-OH
Example
Alcohol
Amine
Aldehyde
Ketone
Carboxylic acid
Ethanol
Ethanamine
Ethanal
Acetone
Acetic acid
NameFamilyFunctionalgroup
CH3COCH2CH3
O-C-ORCarboxylic ester Ethyl acetate
O
O
O
O
H
• Carboxylic acids: contain the carboxyl group (-COOH), which is a carbonyl group attached to a hydroxyl group.
• Esters: the hydroxyl group of a carboxylic acid is replaced by a carbon
atom.
Carboxylic acids and Esters
O
O
O
O
C
C
C
C
H
-OH
-NH2
-C-H
-C-
CH3CH2OH
CH3CH2NH2
CH3CHO
CH3CCH3
O
CH3COHO
-C-OH
Example
Alcohol
Amine
Aldehyde
Ketone
Carboxylic acid
Ethanol
Ethanamine
Ethanal
Acetone
Acetic acid
NameFamilyFunctionalgroup
CH3COCH2CH3
O-C-ORCarboxylic ester Ethyl acetate
O
O
O
O
-OH
-NH2
-C-H
-C-
CH3CH2OH
CH3CH2NH2
CH3CHO
CH3CCH3
O
CH3COHO
-C-OH
Example
Alcohol
Amine
Aldehyde
Ketone
Carboxylic acid
Ethanol
Ethanamine
Ethanal
Acetone
Acetic acid
NameFamilyFunctionalgroup
CH3COCH2CH3
O-C-ORCarboxylic ester Ethyl acetate
O
O
O
O
• Amines: the functional group is a nitrogen atom.
|
— N —
• Amides: the hydroxyl group of a carboxylic acid is replaced by a nitrogen group.
Amines and Amides
O
C
C CC
NN
N
-OH
-NH2
-C-H
-C-
CH3CH2OH
CH3CH2NH2
CH3CHO
CH3CCH3
O
CH3COHO
-C-OH
Example
Alcohol
Amine
Aldehyde
Ketone
Carboxylic acid
Ethanol
Ethanamine
Ethanal
Acetone
Acetic acid
NameFamilyFunctionalgroup
CH3COCH2CH3
O-C-ORCarboxylic ester Ethyl acetate
O
O
O
O
NR