ortho-xylene

Ortho-xylene is one of three isomers of dimethylbenzene, meaning it has the same chemical formula as its isomers, meta-xylene and para-xylene, but a different molecular structure. The term "isomer" comes from Greek words meaning "equal parts," highlighting that these molecules share the same atoms but are arranged differently.12

In ortho-xylene, the two methyl groups are attached to adjacent carbon atoms on the benzene ring. This specific arrangement distinguishes it from meta-xylene, where the methyl groups are separated by one carbon atom, and para-xylene, where they are opposite each other on the ring. These structural differences lead to distinct chemical and physical properties, making each isomer unique despite having the same constituent atoms.12