Experimental discharge spectrum of naphthalene recorded in the 2–12GHz frequency range. The spectrum was acquired across two frequency ranges: 2–8GHz and 8–12GHz. This required the use of different power amplifiers as described in the experimental section. The black trace shows the experimental spectrum. The colored traces are the simulated spectra of the identified species based on the experimental rotational constants and at a rotational temperature of 3 K. The zoom-in at the bottom-left of the spectrum shows the assignment of the newly identified species: 1,2-diethynylbenzene.