The equilibrium structure of Os(CO)(5) in small alcohol solvents has been investigated using FTIR spectroscopy. It was determined that 74100% of Os(CO)(5) forms a complex with a single solvent molecule. The results demonstrate that complex formation is more favorable for the less stable isolated metal pentacarbonyl. The thermodynamics of complexation for Os(CO)(5) in isopropanol were Delta H = -30 +/- 2 kJ/mol, Delta S = -80 +/- 6 J/K mol, and Delta G = -6.0 +/- 0.6 kJ/mol. The FTIR spectra show that the frequency of the OPC nu(1) mode is 21272128 cm(-1) in these solvents. (C) 2015 Elsevier B.V. All rights reserved.