Chemicals, properties carbon—chlorine bond

The arrangement of elements in the molecule, the symmetry of the structure, and the polymer chains degree of branching are as important as the specific elements contained in the molecule. Polymers containing the carbon-hydrogen bonds such as pol5 ropylene and polyethylene, and the carbon-chlorine bonds such as PVC and ethylene chlorotrifluoroethylene are different in the important property of chemical resistance from a fully fluorinated pol)nner such as polytetrafluoroethylene. The latter has a much wider range of corrosion resistance. 

Chloroform, CHCla, is an example of a polar molecule. It has the same bond angles as methane, CH4, and carbon tetrachloride, CCLi- Carbon, with sp3 bonding, forms four tetrahedrally oriented bonds (as in Figure 16-11). However, the cancellation of the electric dipoles of the four C—Cl bonds in CCL does not occur when one of the chlorine atoms is replaced by a hydrogen atom. There is, then, a molecular dipole remaining. The effects of such electric dipoles are important to chemists because they affect chemical properties. We shall examine one of these, solvent action. 

Chemical Properties of Acetylene.—Acetylene and other substances which contain two carbon atoms joined by a triple bond, show in their chemical behavior a high state of unsaturation. Acetylene does not react with chlorine in the dark, but in diffused daylight addition of the halogen takes place, and a dichloride, C2H2CI2, and a tetrachloride, C2H2CI4, are formed. If the acetylene has not been carefully purified, the reaction often takes place with explosive violence and carbon and hydrogen chloride are formed. When the gas is passed into bromine the chief product of the reaction is acetylene tetrabromide —... 

Thus, functionality is not an absolute property of a group, but always has to be considered in relation to the reaction partner. The chemical structure of the resulting macromolecules, moreover, will be decided not only by the functionality of the groups capable of polymerization, but also by the functionality of the molecules. The carbon-carbon double bond in vinyl chloride is bifunctional with respect to free radical polymerization initiators. However, the radicals can also attack already formed polymer, where, for example, a chlorine atom is abstracted with termination of a growing end and formation of a new polymer radical. The new polymer radical can in turn initiate vinyl chloride polymerization again ... 

The unique property of carbon atoms—that is, the property that makes it possible for millions of organic compounds to exist—is their ability to share electrons not only with different elements but also with other carbon atoms. For example, two carbon atoms may be bonded to one another, and each of these carbon atoms may be linked to other atoms. In ethane and hexachloroethane, each carbon is connected to the other carbon and to three hydrogen atoms or three chlorine atoms. Although they have two carbon atoms instead of one, these compounds have chemical properties similar to those of methane and tetrachloromethane, respectively. 

Couper says carbon has two highly distinctive properties (i) it combines with equal numbers of equivalents of hydrogen, chlorine, oxygen, sulphur, etc. (2) it enters into chemical union with itself. These two properties, in my opinion explain all that is characteristic of organic chemistry. The second property is, so far as I am aware, here signalised for the first time. When hydrogen and oxygen are replaced by equivalents of chlorine, etc., the carbon remains united to carbon. Substitution reactions prove beyond doubt that carbon enters into chemical union with carbon, and that in the most stable manner. Couper s formulae were used, but without bonds, by Wurtz. Couper s formula for alcohol may be compared with Kolbe s and the modern formula ... 

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