Functional Groups

 

• Alcohols, Halides,Ethers, and Keytones
• Organic Compounds can contain elements other than C and H, these are known as Functional Groups
• Carbon Chain without functional groups are written R-OH
• There are 9 different functional groups

1. Alcohols         
2. Ketones                       
3. Amines            
4. Halides           
5. Carboxylic Acids         
6. Amides       
7. Aldehydes      
8. Esthers                         
9. Esters

I) Alcohols

• is a hydrocarbon with a -OH bonded to it
• Parent ends with -ol
• Ie: 2 methyl 3 pentaol, 2 ethyl 2,3 dimethyl 1 butanol
•  If there is more than 1 -OH bonded, ending becomes (-diol,triol.tec)
• IE. 1 2 Ethandiol

II) Halides

• Groups 7 [F CL Br I ] 
• Floro/Chloro/Bromo/Ido
• IE) 4 ethyl 2 methyl 1 bromo cyclohexane

III) Keytones

• a double bonded oxygen
• add -one to ending

IV) Aldehydes

• doubled bonded oxygen
• add -al to ending
• simplest form is "Formaldehyde"

Methanol= "Formaldehyde"

V) Carboxylic Acids

• Change the parent chain to -oic acid
• Simplest form  Methanoic Acid

 VI) Ethers

• Oxygen group connected to two alkyl
• 2 carbon chains connected by O2
• Names the smallest 1st
• Name the 2nd alkyl followed by the ether
• Dimethyl Ether

Aromatic Nomenclature

• A benzene molecule is given a special diagram to show it's unique bond structure
• Benzene can be a parent chain or a side chain
• If it is a side chain benzene is called Phenyl

 

 

Phenyl

Alicylics & Aromatics

 A) Alicylics

• Carbon chains can form 2 types of closed loops 
• Alicylics are loops that are usually made with single bonds
• If the parent chain is a loop standard naming rules apply with one addition:

==>"Cyclo" is added in front of the parent chain

• There are 3 different ways to draw compounds:
  
   Example: Cyclopentane

                1) Complete structural diagram

 

2) Condensed structural diagram 

 

3) Line diagram 

• Numbers can start anywhere and can go C.W or C.C.W on the loop
• The Side chain numbers must be the lowest possible
• Loops can also be side chains
• The side chain though, is given the "cyclo" prefix 
• IE: 2 Cyclobutyl Octane

B) Aromatics

• Benzene(C6H6) is a cyclic hydrocarbon with unique  bonds between the carbon atoms
• Structurally it can be drawn with alternating double bonds
• Analysis shows that all six carbon bonds are identical and really represents a 1.5 bond
• This is due to the e- resonance
• e- are free to move all around the ring.

Benzene

Benzene (Lines represent double bonds)

Polar Molecules

• Have an overall charge separation
• Unsymmetrical Molecules are usually polar
• Molecular Dipoles are results of unequal sharing of electrons in a molecule

 

Non Polarity

A) Predicting Polarity

If a molecule is symmetrical the pull of e- is usually balanced

Molecules can be unsymmetrical in two ways:

1) Different Atoms

2) Different number of atoms

Bonding ===>Bonds and Electronegativity

Three types of Bonds

1.Ionic (Metal)-Nonmetal)

• e- are transferred from metal to non-metal

2.Covalent (Non-metal ==> nonmetal)

• e-  are shared between non-metals

3. Metallic (Metal)
Holds pure metals together by electrostatic attraction

A) Electronegativity:
Electronegativity (en) is a measure of an atom's attractions for electrons in a bond

• Fluorine = 4.0 (the most en)
• Chlorine = 3.0
• Cesium = 0.8

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• Atoms with greater en attracts e- more. 
• Polar Covalent: Bonds form from an unequal sharing of e- (H2O) 
• Non-Polar Covalent: Bonds  form from equal sharing

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B) Bonds
The type of bond formed can be predicated by looking at the difference in Electronegativity(en) of elements.
  en > 1.7 = Ionic Bonds
  en < 1.7 = Polar Covalent
  en = 0 is non polar 

< = Less than
> = Greater than

Acid-Base Reactions (Strong Acids & Strong Bases)

• Strong Acids (SA0 dissociate to produce H+ ions.
• H+ions make something acidic
• HCL, H2SO4, HCLO4
• Strong Bases (SB) dissociate to produce off ions.
• NaOH, Ba(OH), LiOH,  (NH3+H2O --->NH4+OH)
• When a SA and SB mix they form Water (H2O) and Ionic Salt.
• Total Volume Changes

pH and pOH

• pH measures of the hydrogenions present in a solution 
• pH= -log[H+]
• pOH is measure if the hydroxide ions present in a solution
• pOH= -log[OH-]

More Functional groups

CARBOXYLIC ACIDS
- carboxylic acids are formed by the function group:

- use standard rules but change the parent chain ending to -oic
- the simplest carboxylic acid is methanoic acid


ETHERS
- an ether contains an oxygen group connected to two alkyl (carbon) chains

- name the small alkyl group first, then the second alkyl group followed by ether.

some examples of ethers

1) dimethyl ether:

2) propyl hexyl ether:
CH3-CH2-CH2-O-CH2-CH2-CH2-CH2-CH2-CH3

3) diphenyl ether: