热烈祝贺秦雷和周国军在JACS上发表题为"Topological Self-Assembly of Highly-Symmetric Lanthanide Clusters: A Magnetic Study of Exchange-Coupling “Fingerprints” in Giant Gadolinium(III) Cages"的论文。

论文TOC

Abstract: The creation of a perfect hollow nanoscopic sphere of metal centres is clearly an unrealisable synthetic challenge. It is however an inspirational challenge, from the viewpoint of chemical architecture and also as finite molecular species may provide unique microscopic insight into the origin and onset of phenomena such as topological spin-frustration effects found in infinite 2D and 3D systems. Herein, we report a series of high symmetry gadolinium(III) (S = 7/2) polyhedra, Gd₂₀, Gd₃₂, Gd₅₀ and Gd₆₀, to test an approach based on assembling polymetallic fragments that contain different polygons. Structural analysis reveals the Gd₂₀ cage resembles a dodecahedron; the vertices of the Gd₃₂ polyhedron exactly reveal symmetry O_h; Gd₅₀ displays an unprecedented polyhedron in which an icosidodecahedron Gd₃₀ core is encapsulated by an outer Gd₂₀ dodecahedral shell with approximate I_h symmetry; and the Gd₆₀ shows a truncated octahedron geometry. Experimental and theoretical magnetic studies show that this series produces the expected antiferromagnetic interaction that can be modelled based on classical spins at the Gd sites. From the magnetization analyses we can roughly correlate the derivative bands to the Gd-O-Gd angles. Such a magneto-structural correlation may be used as “fingerprints” to identify these cages.