Thermal chemistry of Mn₂(CO)₁₀ deposited on MgO thin films

Adsorption of Mn₂(CO)₁₀ at 90 K on MgO(100) thin films grown onto Mo(100) has been investigated using thermal desorption spectroscopy and infrared reflection-absorption spectroscopy. The results of infrared spectroscopy are compared with gas-phase and solid-state studies of Mn₂(CO)₁₀. Heating a deposit of 3.5 monolayers to 800 K showed first molecular desorption and an ordering of the layers towards the crystalline phase at low temperature followed by decarbonylation as the temperature increases. At 800 K only a small amount (1-3% of a monolayer of manganese) of the initial deposit remained on the surface, anchored to defects. A CO stretching frequency was still observed at this temperature and was attributed to CO strongly bound to the remaining manganese.