The equilibrium structure of Ru(CO)(5) in butanol, ethanol and isopropanol has been investigated using FTIR spectroscopy and DFT-D calculations. It was determined that 88-100% of the Ru(CO)(5) molecules form a weak hexacoordinated complex with a single alcohol molecule under ambient conditions. Complexation of Ru(CO)(5) is more favorable than Fe(CO)(5) in all solvents studied. The DFT-D calculations predict that the complex formation occurs via electron donation from the complexing alcohol molecule to Ru(CO)(5) at an equilibrium distance of similar to 375 pm from the metal center to the hydroxyl oxygen. (C) 2012 Elsevier B. V. All rights reserved.