What is the general formula for substituted aromatic compounds, and substituted arenes in particular?

Question

Isaac Aronson · Accepted Answer

I am not sure what you want......#C_6H_5X#?

And of course, #C_6H_5X# specifies four degrees of unsaturation: 3 formal double bonds, and a ring. The #X# group (commonly used for halogens) could be any functional group.

Brooklyn Barber · Answer

I can think of general formulas for two homologous series of aromatic compounds.

A homologous series is a collection of compounds with the same general formula in organic chemistry, typically achieved by changing the number of carbon atoms. Based on the number of #"CH"_2# groups If we start with benzene and add #"CH"_2# groups, we get the series The string "C"_6"H"_6, "C"_7"H"_8, "C"_8"H"_10, "C"_9"H"_12,... It is common to start the general formula for a homologous series with #n = 1#. This provides us with the overall formula. #"C"_text(n+ 5)"H"_text(2n + 4), n = 1, 2, 3, …# Based on the Hückel #4n + 2# rule This provides us with the annulene series: #"C"_6"H"_6, "C"_10"H"_10, "C"_14"H"_14, "C"_18"H"_18, …# If we start the series with #n = 1#, we get the general formula for another aromatic series: #"C"_text(4n+2)"H"_text(4n+2), n = 1, 2, 3, …#

Santiago Alfonso · Answer

undefined The general formula for substituted aromatic compounds, including substituted arenes, is:

$$ \text{C}_6\text{H}_5\text{X} $$

Where $\text{X}$ represents the substituent group attached to the benzene ring.