Annealing reactions of carbon atoms, molecules, and their anions, trapped in noble gas matrices, were studied spectroscopically. To this aim C-n(-) (n=1-4) anions were mass-selected and codeposited with argon or neon to form matrices at low temperatures. The charged species were neutralized by uv irradiation. Carbon chain elongation is observed only if neutral or charged atomic carbon is present in the matrix. Spectra of linear carbon clusters up to C-11 were observed after C- deposition, electron detachment, and subsequent annealing. The reaction between two C-n (n greater than or equal to 2) species in solid argon or neon was studied and can be disregarded even at temperatures near the point of matrix sublimation. (C) 1997 American Institute of Physics.