We tested and applied a laser-induced oxidation method for identifying the IR-active stretching mode absorptions of linear C2n +1 molecules which have known strong UV-vis absorptions. For this purpose, we trapped the molecules of carbon vapor in non-inert matrices (pure O-2 and Ar-O-2 mixtures) at temperatures providing molecular growth. The matrix was exposed to laser light tuned to the wavelength of the UV-vis transition of a specific carbon species. We observed a bleaching of that UV-vis absorption and a correlated decrease of lines in the IR spectra for C-9, C-11, C-13, C-15, and C-21. The data suggest that the strongest IR absorptions of the C2n +1 (n >= 4) chains form a regular pattern with increasing n. To obtain information about IR absorptions of carbon chain oxides, oxygen matrices with replaced O-16 ->O-18 isotopes were applied. Our data revise some of the IR assignments existing in the literature.