Pd 12 M n L 24 (for n = 6, 8, 12) nanospheres by post-assembly modification of Pd 12 L 24 spheres.

In this contribution, we describe a post-assembly modification approach to selectively coordinate transition metals in Pd 12 L 24 cuboctahedra. The herein reported approach involves the preparation of Pd 12 L 24 nanospheres with protonated nitrogen donor ligands that are covalently linked at the interior. The so obtained Pd 12 (LH + ) 24 nanospheres are shown to be suitable for coordinative post-modification after deprotection by deprotonation. Selective formation of tetra-coordinated M B in Pd 12 M B 6 L 24 , tri-coordinated M B in Pd 12 M B 8 L 24 nanospheres and two-coordinated M B in Pd 12 M B 12 L 24 nanospheres is achieved as a result of different nitrogen donor ligands. A combination of pulsed EPR spectroscopy (DEER) to measure Cu-Cu distances in the different spheres, NMR studies and computational investigations, support the presence of the complexes at precise locations of the Pd 12 M B 6 L 24 nanosphere. The general post-assembly modification methodology can be extended using other transition metal precursors or supramolecular systems and can guide precise formation and investigation of novel transition metal-complex containing nanospheres with well-defined composition.