Infrared Spectra of Rh12C and Rh13C in Solid Neon and Solid Argon

► Laser ablation of metal carbide alloy targets provide both metal and carbon atoms. ► Rhodium and carbon atoms in condensing argon or neon react to form metal carbides. ► Matrix infrared spectra and DFT calculations provide vibrational frequencies. ► Vibrational fundamentals of RhC are shifted more in solid argon than in solid neon.