S1 SUPPORTING INFORMATION Photochemistry of Cp′Mn(CO) 2 (NHC) (Cp′ = η 5 -C 5 H 4 Me) Species: Synthesis, Time-Resolved IR Spectroscopy and DFT Calculations Madeeha Batool, a Thomas A. Martin, b Andrés G. Algarra, c Michael W. George, a* Stuart A. Macgregor, c* Mary F. Mahon b and Michael K. Whittlesey b* a School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK b Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK c Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK. CONTENTS Computed coordinates S-2 Results of AIM study S-8