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Structural formulas of ethyl and larger branches

I know how to give the structural formula for molecules with methyl branches, for example, 2-methylpropane would be CH3CH(CH3)CH3 where the bracket shows where the branch is in the molecule.

However, I'm not sure how you go about naming ethyl or larger branches, for example, 3-ethylpentane. Would you need to have two sets of brackets as such: CH3CH2CH(CH2)(CH3)CH2CH3? Or would you put the whole branch in the bracket as such: CH3CH2CH(C2H5)CH2CH3?

Reply 1

smileypotato

You'd want to put the whole side-chain in the brackets. As it's the structural formula, you should also write the ethyl chain in structural formula too - so it'd be CH3CH2CH(CH2CH3)CH2CH3.

You might put two sets of brackets if you had multiple side chains coming off the carbon, such as with CH3CH2CH2C(CH3)(CH2CH3)CH2CH2CH3.