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# Basic Principles of Organic Chemistry ## Introduction * Fundamental element in all organic compounds is carbon * Carbon is the backbone of all organic compounds making up our daily diet. ## Structures of organic compounds * Atoms are denoted by their symbols and all covalent bonds are represente...

# Basic Principles of Organic Chemistry ## Introduction * Fundamental element in all organic compounds is carbon * Carbon is the backbone of all organic compounds making up our daily diet. ## Structures of organic compounds * Atoms are denoted by their symbols and all covalent bonds are represented using a dash joining mutually bonded atoms ### Example: * The structural formula of CH4 is: H H - C - H H ### Electron Dot Structure * The valence electrons of all atoms are shown as dots around them. Two dots indicate one covalent bond. * Example: The electron dot structure of methane is: H H C H H * Electron dot structures are called **Lewis Structures** and the dash formula represents a simplified **Lewis Formula**. * Chemists have come up with more ways to represent organic molecules fulfilling specific requirements ### 14.2.1 Condensed Formula * This is a simplified structural formula where covalent bonds are hidden, and the number of identical groups attached to an atom are shown using a subscript. * Example: the condensed formula of ethane can be written as CH3 - CH3 or CH3CH3 ### 14.2.2 Bond Line Formula or Zig-Zag Formula * In this, the symbols of carbon and hydrogen atoms are not written. * Lines are drawn in a zig-zag manner representing carbon-carbon bonds. * The terminals of the zig-zag line represent methyl groups * The intersection denotes a carbon atom bonded to an appropriate number of hydrogen atoms. * Example: Propane is represeted using the zig-zag formula. * Heteroatoms and hydrogen atoms bonded to heteroatoms are written clearly. * Example: The bond line formula of C2H5OH is: OH ### 14.2.3 Drawing the molecule dimensions * Most organic molecules are used to represent three dimensional shapes. * There are three methods used to represent these molecules on plane paper: #### 1. Wedge Formula * This is a 3-D view of the molecule on a plane paper. * Represented by a solid wedge and a normal line. * The solid wedge is used to represent a bond pointing towards the viewer. * The normal line is used to represent a bond going away from the viewer or below the plane of the paper. #### 2. Fischer Formula * This method represents the dimension of the molecule on a plane paper.