Crystallographic measurements were made with monochromatic Cu radiation (λ = 1.54184 Å) using a Rigaku Synergy-i diffractometer. Raw data processing utilised the program CrysalisPro. [5] The structure was solved using direct methods and was refined against F 2 to convergence using all unique reflections and the program Shelxl, [6] as implemented within WinGX. [7] The THF solvent of crystallisation was found to be disordered, see deposited cif for details. The disordered solvent was modelled across two sites and appropriate restraints and constraints were added to ensure approximation to normal geometry and displacement behaviour. Selected crystallographic and refinement parameters are given in Table and full information in cif format has been deposited with the CCDC as reference number 2380109.