Synthesis, Structure, and Magnetic Properties of Three Chiral Sodium‐Centered Polynuclear Copper(II) Clusters with L ‐Alanine

Silver complexation by metallacryptates

We report the first complete characterization of metallycryptates encapsulating Ag(I) cations: carboxylato ligands derived from l-proline and l-alanine chelate and bridge six Cu(II) centres arranged in a slightly distorted octahedral fashion. Eight oxygen atoms of these ligands are disposed in square-prismatic geometry and coordinate the monovalent cation. Two alternative metallacryptates based on alanine have been identified which differ with respect to aggregation: a solid in which pairs of encapsulating sites are formed competes with an infinite chain of M(I) coordinating sites. In contrast, the individual encrypting moieties are arranged as overall neutral and isolated molecular species in the proline-based metallacryptate. This proline derivative can accomodate Ag(I) and Na(I) cations and form a solid solution. Susceptibility measurements confirm ferromagnetic interactions between the Cu(II) within the hexanuclear proline cryptate and thus underline the similarity between solids accommodating Na(I) and Ag(I). Spectroscopic results suggest that these metallacryptates hardly dissociate in methanol solution.

Syntheses, structures, and properties of a series of novel high-nuclear 3d–4f clusters with mixed amino acids as ligands: {Ln6Cu24}(Ln = Gd, Tb, Pr and Sm)

The first examples of high-nuclear 3d–4f heterometallic clusters {Ln₆Cu₂₄}(Ln = Gd, Tb, Pr and Sm) with mixed amino acid ligands are reported.

A unique 1-amino-1-cyclopropane carboxylate cupric-cryptate hosting sodium

The first cluster containing acc was prepared via supramolecular self-assembly. This Cu(II) cluster traps Na(+), as shown in the solid state by the crystal structure and in solution by ESI-MS. Further characterisations revealed a ferromagnetic intracluster exchange and an irreversible reduction with a rapid intracluster electron transfer.