Naming Organic Compounds

Alkane

• An alkane is a hydrocarbon in which all the carbon atoms are connected by single bond.

Rules

• Number the carbon atoms in the parent chain.
• Using the correct substituent name (methyl, ethyl, chloro,etc.), and the carbon atom number on the parent chain.
• If a particular substituent occurs more than once, use a prefix (di-, tri-, tetra-) to indicate the number of those substituents.
• List the alkyl substituents in alphabetical order.

Formula	Name
CH4	Methane
C2H6	Ethane
C3H8	Propane
C4H10	Butane
C5H12	Pentane
C6H14	Hexane
C7H16	Heptane
C8H18	Octane
C9H20	Nonane
C10H22	Decan

 

Cycloalkanes

• Hydrocarbon chains which connect in a head-to-tail circle are called cyclic hydrocarbons or cycloalkanes.

Rules

• A single substituent does not use a number to indicate the position of attachment
• If there are more than on substituent, the first substituent is assumed to be at the "1" position and the remaining substituents are numbered either clockwise or counterclockwise so as to have the lowest set of overall values.

Alkyl Halides

Rules

• Attached F, Cl, Br and I atoms are called "fluoro", "chloro", "bromo" and "Iodo" groups
• If more than one of the same kind of galogen is present, use the prefix di, tri, etc.
• If a compound contains both alkyl and halo groups, list the attached groups in alphabetical order.

Mutiple Bonds

• An alkene is an organic compound containing a carbon-carbon double bond.
• An alkyne is an organic compound containing a carbon-carbon triple bond.

Rules

• If a double bond is present, change the "ane" ending of the parent hydrocarbon to "ene"
• If a triple bond is present, change the "ane" ending of the parent hydrocarbon to "yne"
• Use a number to indicate the lower numbered carbon involved in the bond. The number goes immdiately in front of the name of the parent hydrocarbon.
• Number the parent hydrocarbon to give the double/triple bond the lowest possible mumber. 

Functional groups:

Alcohols

• An alcohol is an organic compound containing an OH group.

Rules

• Number the hydrocarbon chain to give the lowest possible number to the OH group.
• Place the number immediately before the name f the parent hydrocarbon, separated by a dash. Alkyl groups are placed in front of the number for the OH.
• Indicate the presence of an OH group by changing the "e" ending of the hydrocarbon chain to "ol".

Aldehydes

• An Aldehydes is an organic compound containing a C=O group at the end of a hydrocarbon chain.

Rules:

• Number the-longest carbon chain starting with the -CHO group.
• Name the parent compound by using the alkane name and replacing the -e ending with an -al ending.

Ketones

• A ketons is an organic compund containing a C=O group at a psoition other than at the and of a hydrocarbon.

Rules:

• Number the-longest carbon chain starting so that the –C=O group is attached to the carbon atom with the lowest number.
• Name the parent compound by using the alkane name and replacing the -e ending with an -one ending.

Ethers

• An ethers is a organice compound in which an oxygen joins two hydrocarbon groups.

Rules:

• Start with the side group, add "oxy" to the side group name.

Amines

• An amine is an organic compound containing an NH2 group.
• Amines are organice base and react with acids.

Rules:

• Identify the names of the alkyl groups bonded to the nitrogen atom
• Simply replace the alkane -e ending with -amine.
• The format is as follows: (alkyl name)(-amine)

Amides

• An amides is an organic compound containing a CONH2 group.

Rules:

• Amides are commonly named similar to a carboxylic acid, replacing the –oic acid suffix with amide.

Carboxylic Acid

• An carboxylic acid is an organic compound whcih contains COOH group.

Rules:

• Number the-longest carbon chain starting with the -COOH group. Name the parent compound by using the alkane name and replacing the -e ending with an –oic acid ending.

  

VSEPER

  Exclusion of the three electrons in the molecule as follows: solitary the repulsion between the electrons(lone-lone exclusion); solitary electronic and bonding electron repulsion between the (solitary - into exclusion); bonding electron pairs ofrepulsion between the (into the  - into the exclusion).  Molecules will try to avoid such exclusion to maintain stability.  Exclusion can not be avoided, the molecules tend to form a rejection of the weakest structures.  Lone pair repulsion between the electrons is electronic and bonding, which in turn is greater than the repulsion between the bonding electron pairs.  Therefore, the molecules tend to be the weakest into- into exclusion.

Electronegativity and Polarity

Electronegativity

-Electronegativity Table

 

- Electronegativity is a measure of the attraction of an atom for electrons in a covalent bond.

- Fluorine, the most reactive non-metal, is assigned the highest value since it has the greatest attraction for the electron being shared by the other element. Oxygen is also highly electronegative and has a strong attraction for electrons.
- Metals have low electronegativities since they have weak attraction for any shared electrons.
- When two unlike atoms are convalently bonded, the shared electrons will be more strongly attracted to the atom of greater electronegativity. Such a bond is said to be polar. A polar bond results in the unequal sharing of the electrons in the bond.

Polarity

- Polarity is a physical property of compounds which relates other physical properties such as melting and boiling points, solubility, and inter molecular interactions between molecules.

- For the most part, there is a direct correlation between the polarity of a molecule and number and types of polar or non-polar covalent bonds which are present.

- In a few cases, a molecule may have polar bonds, but in a symmetrical arrangement which then gives rise to a non-polar molecule such as carbon dioxide.

              

Chemical Bonding

Electrostatic Force

-Force existing as a result of the attraction or repulsion between two charged particles.

All bonding is based on the electrostatic relationship.

1) Opposite charge attract each other.

2) Like charges repel each other.

3) The greater the distance between two charged particles, the smaller the attractive force             existing between them.

4) The greater the charge on the particles, the greater the force of attraction between them.

   - This force operates equally in all directions meaning that positively - charged particles attract negatively - charged particles every way.

Ionic Bond

- An ionic bond is formed by the attraction of a positive ion to a negative ion and is formed when an electron from one atom is transferred to another atom, so as to create on positive and one negative ion.

Polar and Non Polar Covalent Bond

polar Covalent Bond

- A bond between 2 nonmetal atoms that have different electronegativities and therefore have unequal sharing of the bonding electron pair

- Example: In H-Cl, the electronegativity of the Cl atom is 3.0, while that of the H atom is 2.1

- The result is a bond where the electron pair is displaced toward the more electronegative atom. This atom then obtains a partial-negative charge while the less electronegative atom has a partial-positive charge.This separation of charge or bond dipole can be illustrated using an arrow with the arrowhead directed toward the more electronegative atom.

The Greek letter delta indicates "partially".

Non-polar Covalent Bond

- A bond between 2 nonmetal atoms that have the same electronegativity and therefore have equal sharing of the bonding electron pair

- Example: In H-H each H atom has an electronegativity value of 2.1, therefore the covalent bond between them is considered nonpolar

 

Bohr, Lewis and Electron Dot Diagrams