Synthesis and Structure of ‘mer’‐Trichlorotetrakis(pyridine)ytterbium(III) Hemipyridine Solvate

The title compound [YbCl3(py)4]·0.5py has been grown as single crystals by the treatment of ytterbium chunks with hexachloroethane in pyridine and characterized by a single crystal X-ray study. It is isomorphous with the previous [LnCl3(py)4]·0.5py array defined for Ln = La, Eu, Er, extending the ‘domain of existence’ of that form to Ln = Yb, an unexpected result given that the Ln = Y adduct with similar seven-coordinate, pentagonal bipyramidal coordination environment, is of an unsolvated form.