[en] Cross sections of single-, double-, and three-electron capture collisions have been measured for the carbon ions passing through the CO₂, CH₄, C₂H₆, and C₃H₈ gas targets at energies between 0.5 and 5 keV/amu. Errors of the obtained cross sections are estimated to be 9 to 20 percents. The cross sections hardly depend on incident energy in the present energy region, but depend on charge of the incident particles and ionization potential of the target molecules. Multiple-electron transfer processes are predominant in these complex molecules. The results of single-electron capture process are discussed in a comparison with theoretical models. (author)