The DFT-calculated spectrum of 1-Y shows that the expected C-F stretches (1106, 767 and 569 cm -1 ) are all observed (see Supporting Information Fig. ). The bulk phase purity of 1-Dy was further demonstrated by powder XRD (see Supporting Information Figs. S7 and S8 and Table ), as the diffraction pattern observed was in excellent agreement with that expected from single crystal XRD data (see below). Le Bail refinement gave reduced unit cell parameters,