Copper Keplerates: High-Symmetry Magnetic Molecules.

Keplerates are molecules that contain metal polyhedra that describe both Platonic and Archimedean solids; new copper keplerates are reported, with physical studies indicating that even where very high molecular symmetry is found, the low-temperature physics does not necessarily reflect this symmetry.

Copper Lanthanide Phosphonate Cages: Highly Symmetric {Cu3Ln9P6} and {Cu6Ln6P6} Clusters with C3v and D3h Symmetry.

Two families of copper lanthanide phosphonate clusters have been obtained through reaction of [Cu2(O2CtBu)4(HO2CtBu)2] and either Ln(NO3)3·nH2O or [Ln2(O2CtBu)6(HO2CtBu)6] and tert-butylphosphonic acid or an amino-functionalized phosphonic acid. The clusters, with general formula [Cu(MeCN)4][Cu3Ln9(µ3-OH)7(O3PtBu)6(O2CtBu)15] and [Cu6Ln6(µ3-OH)6(O3PC(NH2)Me2)6(O2CtBu)12], were structurally characterized through single crystal X-ray diffraction and possess highly symmetric metal cores with approximately C3v and D3h point symmetry, respectively. We have investigated the possible application of the isotropic analogues in magnetic cooling, where we were able to observe that up to around 70% of the theoretical magnetic entropy change is obtained. Simulation of the magnetic data shows antiferromagnetic coupling between the spin centers, which explains the magnetic entropy value observed.

Copper Lanthanide Phosphonate Cages: Highly Symmetric {Cu3Ln9P6} and {Cu6Ln6P6} Clusters with C3v and D3h Symmetry.

Two families of copper lanthanide phosphonate clusters have been obtained through reaction of [Cu2(O2C(t)Bu)4(HO2C(t)Bu)2] and either Ln(NO3)3·nH2O or [Ln2(O2C(t)Bu)6(HO2C(t)Bu)6] and tert-butylphosphonic acid or an amino-functionalized phosphonic acid. The clusters, with general formula [Cu(MeCN)4][Cu3Ln9(µ3-OH)7(O3P(t)Bu)6(O2C(t)Bu)15] and [Cu6Ln6(µ3-OH)6(O3PC(NH2)Me2)6(O2C(t)Bu)12], were structurally characterized through single crystal X-ray diffraction and possess highly symmetric metal cores with approximately C3v and D3h point symmetry, respectively. We have investigated the possible application of the isotropic analogues in magnetic cooling, where we were able to observe that up to around 70% of the theoretical magnetic entropy change is obtained. Simulation of the magnetic data shows antiferromagnetic coupling between the spin centers, which explains the magnetic entropy value observed.