Theoretical Characterization of End-on and Side-on Peroxide Coordination in Ligated Cu2O2 Models

TitleTheoretical Characterization of End-on and Side-on Peroxide Coordination in Ligated Cu2O2 Models
Publication TypeJournal Article
Year of Publication2006
AuthorsCramer, CJ, Kinal, A, Wloch, M, Piecuch, P, Gagliardi, L
JournalThe Journal of Physical Chemistry A
Volume110
Issue40
Pagination11557-11568
Date Published09/15/2006
Abstract

The relative energetics of μ-η1:η1 (trans end-on) and μ-η2:η2 (side-on) peroxo isomers of Cu2O2 fragments supported by 0, 2, 4, and 6 ammonia ligands have been computed with various density functional, coupled-cluster, and multiconfigurational protocols. There is substantial disagreement between the different levels for most cases, although completely renormalized coupled-cluster methods appear to offer the most reliable predictions. The significant biradical character of the end-on peroxo isomer proves problematic for the density functionals, while the demands on active space size and the need to account for interactions between different states in second-order perturbation theory prove challenging for the multireference treatments. In the latter case, it proved impossible to achieve any convincing convergence.