Dichloronitrobenzene can refer to any of the following isomers of C6H3Cl2(NO2):
1,2-Dichloro-3-nitrobenzene 1,2-Dichloro-4-nitrobenzene 1,3-Dichloro-2-nitrobenzene 1,3-Dichloro-4-nitrobenzene 1,3-Dichloro-5-nitrobenzene 1,4-Dichloro-2-nitrobenzene
Wikipedia
Dichloronitrobenzene can refer to any of the following isomers of C6H3Cl2(NO2):
1,2-Dichloro-3-nitrobenzene 1,2-Dichloro-4-nitrobenzene 1,3-Dichloro-2-nitrobenzene 1,3-Dichloro-4-nitrobenzene 1,3-Dichloro-5-nitrobenzene 1,4-Dichloro-2-nitrobenzene