In the case of 2 Py , isotopic patterns consistent with the formulation [Pd3(2 Py )6] 6+ were exclusively observed by ESI-MS (Fig. ). The 1 H NMR spectrum had overlapping peaks, although DOSY suggested formation of a main species with RS = 13.5 Å. Upon heating the sample to 80 °C, a sharpening and shift in the resonances of some signals was observed, leading to less overlap (Fig. ), with 15 proton environments becoming apparent. It was concluded that the major assembly was likely a trinuclear architecture with a "knotted" arrangement of ligands. Interestingly, when the SCXRD structure was solved from weakly diffracting crystals, the solid-state structure was shown to be a Pd2L4 helicate (Fig. ).