Ball and Socket Assembly of Binary Superatomic Solids Containing Trinuclear Nickel Cluster Cations and Fulleride Anions

The superlattice structures of hierarchical cluster solids are dictated by short-range interactions between constituent building blocks. Here we show that shape complementary sites, as well as halogen and chalcogen bonding between exposed capping ligands and fullerides, govern the packing arrangement of the resulting binary solids. Four new superatomic solids, [Ni₃(μ₃-I)₂(μ₂-dppm)₃⁺]­(C₆₀^•‑) (<b>1·</b>C₆₀), [Ni₃(μ₃-I)₂(μ₂-dppm)₃⁺]­(C₇₀^–)₂ (<b>1·</b>C₇₀), [Ni₃(μ₃-Te)₂(μ₂-dppm)₃⁺]­(C₆₀^•‑) (<b>2·</b>C₆₀), and [Ni₃(μ₃-Te)₂(μ_2‑dppm)₃]­(C₇₀^–)₂ (<b>2·</b>C₇₀), (dppm = Ph₂PCH₂PPh₂) were prepared and crystallized from solution. All four compounds were characterized by single crystal X-ray diffraction, IR spectroscopy, and SQUID magnetometry. Charge transfer between the molecular clusters is confirmed via optical spectroscopy and structural data. Compounds <b>1·</b>C₆₀ and <b>2·</b>C₆₀ are paramagnetic and 100 times more conductive than the constituent cluster precursors. The obtained solids exhibit close contacts, indicative of halogen/chalcogen bonds, between the fulleride anions and the nickel cluster capping ligands (I/Te) in the solid-state

Ferromagnetic Ordering in Superatomic Solids

In order to realize significant benefits from the assembly of solid-state materials from molecular cluster superatomic building blocks, several criteria must be met. Reproducible syntheses must reliably produce macroscopic amounts of pure material; the cluster-assembled solids must show properties that are more than simply averages of those of the constituent subunits; and rational changes to the chemical structures of the subunits must result in predictable changes in the collective properties of the solid. In this report we show that we can meet these requirements. Using a combination of magnetometry and muon spin relaxation measurements, we demonstrate that crystallographically defined superatomic solids assembled from molecular nickel telluride clusters and fullerenes undergo a ferromagnetic phase transition at low temperatures. Moreover, we show that when we modify the constituent superatoms, the cooperative magnetic properties change in predictable ways