Stability, primary carbon, two carbon, three carbon, four carbon
In hydrocarbon molecules, with 3 hydrogen atoms of carbon atoms is called the first carbon atom (also called a carbon atom or primary carbon atom); with 2 hydrogen atoms of the carbon atoms is called second carbon atom (also called the two carbon atoms or secondary carbon atoms); with 1 hydrogen atoms of the carbon atoms is called third carbon atoms (also called the three carbon atom or tertiary carbon atoms)
(2) due to free radicals generated in the outer layer of only 7 electrons, eight corner structure did not reach saturation, so it is an electron deficient species, while methyl (or alkyl) is an electron donor groups can alleviate the lack of this kind of electron, so that the stable free radicals, free radicals and carbon alkyl substituents on the more, the more stable free radical. And more stable, more easy to generate.
From a variety of hydrogen is substituted alkyl free radicals generated in terms of difficulty order can have free radicals for the formation of tertiary carbon free radical secondary carbon free primary carbon free radicals. Alkyl radicals generated methyl easily, can be explained from two aspects: (1) different required to form free radicals when the fracture of C-H the energy, the (CH3) 3C-H fracture, the energy required for the smallest, most easily generated.
