Carbon of ch4 is called super primary carbon but why
Answers
Explanation:
We use the terms primary, secondary, tertiary and quaternary at various times during the organic and biochemistry sections of the course. In each case, the terms somehow refer to the numbers 1, 2, 3 and 4, respectively. However, the exact connotations depend on the context.
The purpose of this page is to bring all the meanings together, for direct comparison. The presentations here are brief; the main goal is comparison, not original presentation.
Specific book references are to the Organic/Biochem (X402) textbook, Ouellette 2/e.
For brevity, the set of terms from primary to quaternary sometimes will be referred to as "primary (etc)".
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Carbon atoms
A (saturated) carbon atom in an organic molecule is classified as primary (etc) depending on how many other C atoms are attached to it.
The following table illustrates this:
Table to show meaning of 'primary' (etc.) carbon atoms.
Ouellette 2/e, p 71.
Methane, CH4, is a special case. The C in methane is attached to zero other C. This C is sometimes called primary, for convenience. Alternatively, it can just be considered separate from any of these categories.
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Carbocations
A carbocation (C atom carrying a positive charge) is classified the same way as a regular (neutral) carbon atom, above. That is, if the C of the carbocation is attached to one other C, then it is called a primary carbocation, etc.
The book discusses this in the context of addition reactions of alkenes; acid-catalyzed addition of HX proceeds through a carbocation intermediate. Ouellette 2/e p 120.
The same classification scheme is used for C atoms carrying a negative charge (carbanions) or carrying an unpaired electron (free radicals). Carbanions and carbon free radicals are not encountered in this course (though they are mentioned by Ouellette 2/e, in topics that we will not cover).