Emission spectra from collisions of 8 keV He+center dot and H-2(+center dot) with neutral naphthalene, benzene, acetylene and methane were acquired over 190-1020 nmon a modified double-focusing mass spectrometer. The bands, emission intensities and the minimum excitation energy to produce the observed transitions (E-min) were compared for the two projectile ions. E-min values were the same for both projectiles but the emission intensity is greater in the case of He+center dot. This is consistent with calculations at the CISD/6-311+G(2df) level on the excited states of the respective collision complexes which exhibited two distinct state-crossing points for He+center dot collisions but none for H-2(+center dot) collisions. (C) 2016 Elsevier B.V. All rights reserved.