Charge-transfer processes in collisions of ground-state ${\mathrm{C}}^{+}$ ions with ${\mathrm{H}}_2,$ ${\mathrm{D}}_2,$ CO, and ${\mathrm{CO}}_2$ molecules in the energy range from 0.15 to 4.5 keV

Charge-transfer processes in collisions of ${\mathrm{C}}^{+}$ ions with ${\mathrm{H}}_2,$ ${\mathrm{D}}_2,$ CO, and ${\mathrm{CO}}_2$ molecules have been studied based on joint experimental and theoretical approaches in the collision energy from 0.15 to 4.5 keV. In the present experiment, the ground-state ${\mathrm{C}}^{+}{(}^{2}P)$ ion projectiles have been produced by carefully energy-controlled electron impact to minimize the influence of the metastable-state ions. The observed cross sections are compared with the present theoretical prediction, and while the theoretical results are somewhat smaller than the measurements, they are found to be in reasonable agreement for ${\mathrm{H}}_2,$ ${\mathrm{D}}_2,$ and CO above around 1 keV. The present experimental cross sections for CO and ${\mathrm{CO}}_2$ are smaller by a factor of 2 to 3 than those of earlier measurements. We provide some remarks on the effect of the metastable-state ions.