The paramagnetic one-dimensional H NMR spectra of twelve LnNa(OAc)[12-MC-4] complexes, where Ln is Pr-Yb (except Pm) and Y, are reported. Their solid-state isostructural nature is confirmed in methanol-d solution, as a similar pattern in the H NMR spectra is observed along the series. Notably, a relatively well-resolved spectrum is reported for the Gd complex. The chemical shift data are analyzed using the "all lanthanides" method, and the Fermi contact and pseudo-contact contributions are calculated for the lanthanide-induced shift (LIS). For the Tb-Yb complexes, the pseudo-contact contributions are typically 1 order of magnitude higher than the Fermi contact contributions; however, for the Gd complex, the Fermi contact is the main contribution to the paramagnetic chemical shift. For the methyl protons of the axial acetate (OAc) ligands, the LIS is opposite in sign, with respect to that of the aromatic salicylhydroximate (shi) protons, because of structural rearrangements that occur upon dissociation of the Na cation in solution. The calculated crystal field parameters (B) for the Tb (360 cm), Dy (250 cm), Ho (380 cm), Er (410 cm), Tm (620 cm), and Yb (380 cm) complexes are not constant, likely as a consequence of the inaccuracy of the Bleaney's constants and, to a smaller extent, the small structural changes that occur in solution. Overall, the metallacrown scaffold retains structural integrity and similarity in solution for the entire series; however, small structural features, which do not affect the overall similarity, do likely occur.

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Single crystal X-ray structures are presented for three 12-metallacrown-4 complexes, Er III Na(L) 4 [12-MC Mn III (N)shi-4], where L istrimethylacetate (OTMA), benzoate (OBen), or salicylate (OSal), MC is metallacrown, and shi 3is salicylhydroximate: Er III Na(OTMA) 4 [12-MC Mn III (N)shi-4](H 2 O) 3.73 (DMF) 0.27 •7.45DMF•1.47H 2 O, 1, Er III Na(OBen) 4 [12-MC Mn III (N)shi-4](H 2 O) 4 •4DMF•0.87H 2 O, 2, and Er III Na(OSal) 4 [12-MC Mn III (N)shi-4](H 2 O) 3.54 (DMF) 0.73 •4DMF•0.24H 2 O, 3, where DMF is N,N-dimethylformamide.Compounds 1-3 demonstrate the facile ligand variation of a self-assembled supramolecular coordination complex containing three different metal types. In all three structures, the monoanion carboxylate ligands serve as bridges between the central Er III ion and the ring Mn III ions. The structures of 1-3 are all domed towards the side of the central Na + ion, and the 12-MC-4 frameworks of 1-3 are very similar regardless of the monoanion carboxylate bridge, as the metallacrown cavity radii of 1-3 are 0.55 Å, 0.54Å, and 0.55 Å, respectively. In addition, the cross cavity measurementsindicate that the metallacrownframeworks are not significantly altered by the presence of different monoanion carboxylate ligands as the Mn III-Mn III cross cavity distances for 1-3 are 6.52 Å, 6.51Å, and 6.49 Å, respectively, and the oxime oxygenoxime oxygen cross cavity distances for 1-3 are 3.71 Å, 3.68Å, and 3.69 Å, respectively. The conservation of the 12-MC-4 framework among the different structures will be important when assessing the physical properties this class of molecules.

The title compound is an example of a 12-metallacrown-4 self-assembled supra­molecular coordination complex with ring MnIII ions. A YIII ion and Na+ ion are captured on opposite sides of the metallacrown cavity, and the YIII ion is tethered to the metallacrown with four tri­methyl­acetate anions.

The terbium-aluminum metallacrowns (MC), TbAl4Na (left image & capillary) and Tb2Al8Na2 (right image & capillary) emit green light. Tb2Al8Na2 has a quantum yield value of 43.9%, the highest value observed in the solid state to date for a TbIII MC.