Chapter -1 : Carbon Compounds and Chemical Bonds

1.1 Introduction

What is Organic Chemistry?

Organic Chemistry is the chemistry of the compounds of carbon (C) and Carbon is the centrally compound of life on this planet (Earth). Our DNA is also a carbon compound and its large helical molecules contains our entire genetical map.

One theory of the origin of life on Earth tells us that early in Earth's history most of its carbon atoms were present in the form of the gas methane, CH4. See organic chemistry is everywhere around you. The clothing we wear, whether a natural substance such as wool or cotton or a synthetic such as nylon or a polyester, is made up of carbon compounds. Many of the materials that go in to the house that shelter us are organic. The gasoline that propels our automobiles, the rubber of their tires and plastic of their interiors are organic. Most of the medicine that cure us and relieve suffering are organic.

1.2 - The Development of Organic Chemistry as a Science

Human have used organic chemistry and their reactions for many years. As per some ancient record some organic compound like INDIGO and ALIZARIN were used by Egyptian to dye their cloths and "Royal Purple" used by Phoenicians was also an organic compound. The fermentation of grapes to produce wine (ethyl alcohol) and acidic qualities of "Soured Wine" are both described in the Bible.

Vitalism

1. It was originally thought organic compound could be made by living things by interventions of a "vital force"
2. Fredrich Wohler disproved vitalism in 1828 by making the organic compound urea from the inorganic salt ammonium cyanate by evaporation (refer the synthesis given below). Although vitalism disappeared slowly from scientific circle after Wohler's synthesis.

1.3 : The structural theory of Organic Chemistry

Between 1858 and 1861 August Kekule, Archibald Scott Cooper and Alexander M. Butlerow, working independently , laid the basic for the one of the most fundamental theories in chemistry: the Structural Theory.

Two central premises are fundamental

The atoms in organic compounds can form a fix number of bonds. The measure of this ability is called valence. Carbon is tetravalent; that is carbon atoms form four bonds, where Oxygen is divalent and halogens are monovalent;

The above Table 1.1 mentions the properties of Ethyl Alcohol and Dimethyl Ether.

Ethyl alcohol and dimethyl ether are the examples of what are called constitutional isomers. Constitutional isomers are different compounds that have the same molecular formula but differ in their connectivity, that is, in the sequence in which their atoms are bonded together.

They often differ in physical properties (e.g. boiling point, melting point, density) and chemical properties

The Tetrahedral Shape of Methane

Virtually all molecules possesses 3-dimension shape which is often not accurately represented by drawing