Hydrocarbon compounds and their derivatives

Hydrocarbons are also known as hydrocarbons. An organic compound containing only two elements of hydrocarbon. The hydrogen in the molecule is replaced by an atom or a group of other elements to obtain derivatives of various hydrocarbons. The German chemist Xiao Laima discovered hydrocarbons such as butane, which was hailed as the founder of hydrocarbon chemistry. There are many types of hydrocarbons, and there are more than 2,000 structures known. According to the carbon bond connection method, it is divided into two types: chain hydrocarbons and cyclic hydrocarbons. The former carbon atoms are connected in a chain. The degree to which the valence bond is saturated by a hydrogen atom can be further classified into two types, saturated hydrocarbons and unsaturated hydrocarbons. Saturated hydrocarbons are alkanes such as methane, ethane, etc.; unsaturated hydrocarbons are olefins and alkynes, and typical representatives are ethylene and acetylene. The carbon bonds in the cyclic hydrocarbon molecules form a closed ring, which includes both alicyclic hydrocarbons and aromatic hydrocarbons. There are many similarities between alicyclic hydrocarbons and chain hydrocarbons. Generally, cycloalkanes are like alkanes, and cyclic alkenes and cycloalkynes are like olefins and alkynes, respectively. The aromatic hydrocarbon mainly refers to a hydrocarbon having a benzene ring structure. Chain hydrocarbons are also known as aliphatic hydrocarbons because the oils found in the initial study contained many of these open chain compounds. Alicyclic hydrocarbons are named because their properties are similar to those of aliphatic hydrocarbons. The properties of aromatic hydrocarbons are different from those of other hydrocarbons, and several of the first compounds found are scented, so they are named and used today. Oil, natural gas and coal are the main sources of hydrocarbons. Petroleum refining can obtain various alkane mixtures such as gasoline, kerosene, diesel, etc.; petroleum cracking and reforming can obtain various olefins, alicyclic hydrocarbons and aromatic hydrocarbons. Coal tar contains a variety of aromatic hydrocarbons (such as benzene, naphthalene, etc.). Many higher hydrocarbons are also present in plants, and pigments such as tomatoes and carrots are hydrocarbons. Many animal and plant waxes also contain higher alkanes, such as beeswax containing C27H56, C31H64; spinach leaves containing C33H68, C35H72, C37H76; cabbage leaves containing C29H60. The main component of natural rubber, polyisoprene, is also a hydrocarbon. The important use of hydrocarbons is as fuel and chemical raw materials. From the secondary processing of petroleum, basic organic industrial raw materials such as ethylene, propylene, butadiene, benzene, toluene, xylene and naphthalene can be obtained, and further chemical raw materials such as styrene, ethanol and acetone can be further prepared from these raw materials. The use of these raw materials can be processed to produce a variety of plastics, synthetic rubber, synthetic fibers and fine chemical products. Hydrocarbons can also be used as food for certain bacteria, and the protein (petroleum) excreted by these bacteria can be used as feed. The scale and level of processing of hydrocarbon compounds in a country can reflect its level of economic and technological development. A hydrocarbon derivative is a generic term for a more complex compound derived from the substitution of one or more hydrogen atoms in a hydrocarbon molecule by other atoms or groups of atoms. A compound derived by substitution with a halogen is called a halogenated hydrocarbon, a compound substituted with a hydroxyl group is called an alcohol or a phenol, and a compound substituted by a carboxyl group is called a carboxylic acid. An ester, an acid halide, an acid anhydride, an amide, an aldehyde, a ketone, an amine, a nitrile or the like can be considered as a compound derived by substituting a corresponding atomic group for a hydrogen atom in a hydrocarbon molecule. In the early 19th century, the German chemist Xiao Laima first defined organic chemistry as the chemistry of hydrocarbons and their derivatives based on years of experimental research and theoretical discussion. This definition is based on the principle of atomic combination theory. It is more reasonable and progressive than all previous definitions and was adopted by many chemists at that time. But it does not show the difference between organic and inorganic. The definition of Xiao Laima has greatly promoted the development of organic chemical structure theory. He was the first to scientifically classify organic compounds according to the above definition and establish a scientific system. He first divided the organic matter into aliphatic hydrocarbons and aromatic hydrocarbons, and divided the aliphatic compounds into hydrocarbons (saturated hydrocarbons and unsaturated hydrocarbons), halogen hydrocarbons, alcohols, ethers, aldehydes, ketones, acids, esters and the like.