Theoretical characterization of end-on and side-on peroxide coordination in ligated Cu2O2 models.
The relative energetics of mu-eta1:eta1 (trans end-on) and mu-eta2:eta2 (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.
Cramer
Christopher J
CJ
Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, USA.
Kinal
Armagan
A
Włoch
Marta
M
Piecuch
Piotr
P
Gagliardi
Laura
L
D002413:Cations, Divalent / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D007536:Isomerism; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D010087:Oxides / Q000737:chemistry; D010545:Peroxides / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry
D002413:Cations, Divalent; D010087:Oxides; D010545:Peroxides; D000644:Quaternary Ammonium Compounds; C470086:dihydrogen trioxide; D003300:Copper; C030973:cupric oxide