title: Density functional calculations reveal a flexible version of the copper paddlewheel unit: implications for metal organic frameworks.
abstract: Density functional theory calculations on [Cu2(O2CR)4L2] systems reveal a change in ground state with increasing Cu-L bond strength. For L = N-heterocyclic carbene (NHC), the Jahn-Teller axis switches from parallel to orthogonal to the Cu-Cu vector and the copper coordination geometry becomes highly flexible. While the calculated dimer/monomer equilibrium for isolated complexes slightly favours monomers, the preformed paddlewheel units embedded in many metal organic frameworks are potential targets for developing novel materials.
authors.affiliation: Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK. r.j.deeth@warwick.ac.uk.
authors.forename: K A H
authors.initials: KA
authors.lastname: Alzahrani
authors.affiliation: Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK. r.j.deeth@warwick.ac.uk.
authors.forename: R J
authors.initials: RJ
authors.lastname: Deeth