Hydrocarbons, which only have hydrogen and carbon-carbon single bonds in their molecules, are the most basic organic compounds. Natural sources of hydrocarbons include coal, natural gas and petroleum. When hydrogen is substituted for one of the proper functional groups in hydrocarbons, all organic molecules can be considered derivatives of hydrocarbons. Based on their composition, carbon and hydrogen compounds are known as hydrocarbons. There are two primary categories that describe the reactivity of bonds and hydrocarbons.
Saturated (alkanes) and unsaturated hydrocarbons are the two main categories for aliphatic and aromatic hydrocarbons. According to conventional definitions, organic chemistry is the study of the chemistry of molecules containing carbon. This field of research was developed in the 1800s in the labs of highly innovative and creative German chemists, and it now contains an enormous amount of factual information. Over two million organic compounds are thought to be already known, and this figure is growing at a very fast rate.
Aliphatic Compounds
Early research in organic chemistry was frequently inspired by the discovery that particular plant and animal extracts had therapeutic, dietary and colouring (dyeing) benefits. When burned in oxygen, organic materials were consistently discovered to produce carbon dioxide and water, indicating the presence of the elements carbon and hydrogen. It became evident that additional elements were frequently also present as the number of these isolated chemicals increased, with oxygen being the most frequently discovered element.
When organic compounds were first classified, it was useful to distinguish between those that, according to their structure and reactivity, were closely connected to the chemical “benzene” and those that were structurally related to naturally occurring fatty acids. The former was referred to as “aromatic compounds” due to their widespread dispersion in fragrant plant resins, gums and oils, whilst the latter was referred to as “aliphatic compounds.”
Aromatic Hydrocarbon
Aromatic, as used in this context, refers to particular structural features of the molecules rather than to any fragrance that they might have. It was once believed that all hydrocarbons with strong scents possessed these structural characteristics, but it is now evident that this is not always the case because many aromatic hydrocarbons lack any unique olfactory characteristics.
The distillation of coal or petroleum yields benzene, C6H6, the most basic aromatic hydrocarbon. Although it burns easily and is a liquid (bp 80°C), benzene produces black smoke when it is burned. This is a result of the molecule’s high carbon concentration. One might infer that benzene is an unsaturated molecule based on the molecular formula and the fact that every hydrogen atom in the molecule behaves equally in chemical reactions.
As a result, organic chemistry is a vital part of what is known as the “life sciences,” and many fields of biological and medical study benefit from the perspectives and expertise of the organic chemist. The struggles faced by the beginning student in this discipline are exacerbated by the efforts and triumphs of organic chemists, who consistently add to the body of knowledge concerning carbon compounds.
