Cover Picture

The cover picture shows a remarkable Pd(145) nanocluster, whose metal-core geometry was unambiguously characterized from complete analyses of crystallographic X-ray data. This unprecedented close-packed multishell carbonyl metal cluster was isolated from the reduction of a monomeric square-planar palladium precursor Pd(PEt(3))(2)Cl(2)]. The structure is made up of three distinct shells, the outermost of which possesses 60 equivalent vertices along with 12 pentagonal, 20 equilateral triangular, and 30 square faces; this semiregular (Archimedean) polyhedron, named rhombicosidodecahedron (with Schl?fli symbol 3.4.5.4), is a hitherto crystallographically unknown stereoisomer of the universally familiar C(60) buckyball, an icosahedrally truncated semiregular polyhedron of I(h) symmetry with 60 equivalent vertices and 12 pentagonal and 20 hexagonal faces. More about this fascinating nanocluster can be found in the communication by L. Dahl et al. on p. 4121 ff.