Tetradecanuclear polycarbonatolanthanoid clusters: Diverse coordination modes of carbonate providing access to novel core geometries

The synthesis of two high nuclearity lanthanoid clusters demonstrates the versatility of the carbonate anion as a robust cluster forming agent, potentially allowing for the formation of otherwise inaccessible core topologies. The complexes, [Gd(14)(CO(3))(13)(ccnm)(9)(OH)(H(2)O)(6)(phen)(13)(NO(3))](CO(3))(2.5)·(phen)(0.5) (1) and [Dy(14)(CO(3))(13)(ccnm)(10)(OH)(H(2)O)(6)(phen)(13)](CO(3))(2.5)·(phen)(0.5) (2) (ccnm = carbamoylcyanonitrosomethanide, phen = 1,10-phenanthroline), contain a [Ln(14)(CO(3))(13)(OH)] core in which the carbonate anions display four unique coordination modes. The complexes are chiral, and the ccnm ligands also display four unique coordination modes. Extensive intra- and intermolecular π-π stacking between phen ligands leads to the formation of 1D chains in the crystal structure. Both complexes display magnetic properties that are indicative of antiferromagnetic coupling, with complex displaying behaviour consistent with possible single molecule magnet properties.