Population analysis using TD-DFT calculations indicates that excitation of 1a at 456 nm is accompanied by a decrease of the Pd(II)-C bond order by 0.43. The difference density isosurface for this electronic transition (Figure , a) illustrates that the decrease in bond order is correlated to a decrease in electron density at Pd with a concomitant increase in electron density at This journal is © The Royal Society of Chemistry 20xx