Question

Why methene and methyne does not exist $?$

Answer 1

Hint: Hydrocarbons can be classified into saturated, unsaturated and aromatic hydrocarbons based on the type of carbon-carbon bonds. Alkanes are saturated hydrocarbons with carbon-carbon and carbon-hydrogen single bonds. Alkenes and alkynes contain carbon-carbon double and triple bonds respectively. They are unsaturated hydrocarbons. Aromatic compounds are special types of cyclic hydrocarbons.

Complete answer:
The IUPAC naming of organic compounds involves the selection of parent chains. The parent chain must be the longest continuous chain of the compound. The number of carbon atoms in the parent chain is substituted in the “alk” part. The suffix “ane”, “ene” and “yne” denotes single, double and triple bonds respectively. Methane, $C{H}_4$ ,is the first member of the alkane family. ”Meth” stands for one carbon atom. The carbon atom is singly bonded to four hydrogen atoms and thus the suffix “ane”. Now, let us break the words “methene” and “methyne”. “Meth” stands for one carbon atom and suffixes “ene” and “yne” refer to the presence of double and triple bonds between carbon atoms, respectively. We know that an organic compound must contain at least two carbon atoms to form double and triple bonds. Here, there is only one carbon atom and thus we can conclude that methene and methyne does not exist.

Note:
Alkanes are saturated hydrocarbons with single bonds between carbon atoms. Its general formula is $C_n{H}_{2n+2}$ , where $n=1,2,3,4...$ .
Unsaturated hydrocarbons with one more double bond are called alkenes and have the general structure, $C_n{H}_{2n}$ , where $n=2,3,4...$ .
Alkynes are unsaturated hydrocarbons with one or more triple bonds and can be written as $C_n{H}_{2n-2}$ , where $n=2,3,4...$
Ethene $(C{H}_2=C{H}_2)$ is the smallest possible hydrocarbon molecule with a double bond and ethyne $(CH\equiv CH)$ is the smallest molecule with a triple bond.