New strategy to construct single-ion magnets: a unique Dy@Zn₆ cluster exhibiting slow magnetic relaxation.

Two unique heptanuclear clusters Ln@Zn6 (Ln = Dy (1), Er (2)) were structurally and magnetically characterized. Each Dy(3+)/Er(3+) is located in a nona-coordinate D(3h) coordination environment, and is encapsulated in a diamagnetic Zn6 cage. Compound 1 exhibits single-ion magnetic behavior, and is the first example of a single-ion magnet (SIM) constructed through embedding one magnetic anisotropic metal ion into a diamagnetic cage.