Copper-carbon clusters, formed by dual Nd/-YAG laser vaporization, have been trapped in solid Ar at 12 K and investigated by infrared spectroscopy. Density functional calculations of a number of possible molecular structures for Cu/carbon clusters have been performed, and their associated vibrational harmonic mode frequencies and dissociation energies have been determined with a 6-311++G(3df) basis set using both B3LYP and MPW1PW91 functionals. Both computations and C-13-isotopic substitution experiments indicate that new bands observed at 1830.0 and 1250.5 cm(-1) are due to the asymmetric and symmetric C = C stretching modes, respectively, in the near-linear CUC3 (X(2)A') cluster. Photoinduced C-12/13-isotopic scrambling in (CuC3)-C-12/13 clusters has also been observed. The mechanism for the photoscrambling is shown to involve the formation of a bicyclic CuC3 isomer.