Computational study of dissociative electron attachment to π-allyl ruthenium (II) tricarbonyl bromide

Abstract: Motivated by the current interest in low energy electron induced fragmentation oforganometallic complexes in focused electron beam induced deposition (FEBID) we haveevaluated different theoretical protocols for the calculation of thermochemical thresholdenergies for DEA to the organometallic complex π-allyl ruthenium (II) tricarbonyl bromide. Severaldifferent computational methods including density functional theory (DFT), hybrid-DFT andcoupled cluster were evaluated for their ability to predict these threshold energies andcompared with the respective experimental values. Density functional theory and hybrid DFTmethods were surprisingly found to have poor reliability in the modelling of several DEAreactions; however, the coupled cluster method LPNO-pCCSD/2a was found to produce muchmore accurate results. Using the local correlation pair natural orbital (LPNO)methodology, high level coupled cluster calculations for open-shell systems of this sizeare now affordable, paving the way for reliable theoretical DEA predictions of suchcompounds. Graphical abstract: [Figure not available: see fulltext.]