In previous work it was shown that molybdenum oxide based spherical hollow clusters of the type {(Mo)Mo 5 } 12 {linker} 30which, because of their structural features, are also called Keplerates-can be directly synthesized by the addition of linkers, such as V IV O 2+ and Fe III , to a dynamic library containing (virtual) pentagonal units in solution [1, 2] (for general information see also refs. [3-5]). In the {linker} 30 = {M 30 } situation, a network of corner-sharing triangles exists on the sphere surface, [1, 2a] and this gives rise, as in the {Mo 72 Fe 30 } case, to a geometrically frustrated magnetic system which has received a lot of attention. [4d-f, 6] In fact, these zero-dimensional materials share topological features with the planar KagomØ lattices which also support geometrical frustration [7] and are of interest for materials science. [7a] The exploration of distinct yet related spin systems, which is an important aspect of the present work, is expected to provide a deeper understanding of basic aspects of geometrical frustration and especially the role played by varying the spin quantum number of the metal centers. Herein we report the synthesis (and new perspectives for the general synthetic principles leading to these types of capsules) of the spherical, hollow {(Mo)Mo 5 } 12 {Cr III } 30 type cluster 1 a which contains an interesting encapsulated {Na(H 2 O) 12 } type entity. This {Mo 72 Cr 30 }
[*] A.