C₆H₄(C₂H₅)₂ Colorless liquid, boiling at 180-185°C; soluble in organic solvents, insoluble in water; usually a mixture of three isomers, which are 1,2- (or ortho- diethylbenzene), boiling at 183°C, and 1,3- (or meta-), boiling at 181°C, and 1,4- (or para-), boiling at 184°C; used as a solvent.