Experimental and theoretical studies of a novel family of germanium-carbon clusters (GenCm) that were initiated with our earlier identification of the GeC3Ge cluster have now been extended to the GeC7 and GeC9 chains. The new clusters, which were formed by laser ablation and trapped in solid Ar at similar to10 K, have been identified using Fourier-transform infrared (FTIR) measurements coupled with density-functional theory (DFT) calculations. The nu(1)(sigma) vibrational fundamental of linear GeC7 has been identified at 2063.6 cm(-1), and an absorption at 1928.3 cm(-1) has been assigned to the nu(4)(sigma) fundamental of linear GeC9. FTIR measurements of the isotopic shifts for the assignments are in good agreement with the DFT predictions. (C) 2004 American Institute of Physics.