The cyclo‐P4 complexes [CpRTa(CO)2(η4‐P4)] (CpR: Cp′′=1,3‐C5H3tBu2, Cp′′′=1,2,4‐C5H2tBu3) turned out to be predestined for the formation of hollow spherical supramolecules with non‐classical fullerene‐like topology. The resulting assemblies constructed with CuX (X=Cl, Br) showed a highly symmetric 32‐vertex core of solely four‐ and six‐membered rings. In some supramolecules, the inner cavity was occupied by an additional CuX unit. On the other hand, using CuI, two different supramolecules with either peanut‐ or pear‐like shapes and outer diameters in the range of 2–2.5 nm were isolated. Furthermore, the spherical supramolecules containing Cp′′′ ligands at tantalum are soluble in CH2Cl2. NMR spectroscopic investigations in solution revealed the formation of isomeric supramolecules owing to the steric hindrance caused by the third tBu group on the Cp′′′ ligand. In addition, a 2D coordination polymer was obtained and structurally characterized.

Pentaphosphaferrocenes [CpRFe(η5‐P5)] (1) and CuI halides are excellent building blocks for the formation of discrete supramolecules. Herein, we demonstrate the potential of Cu(CF3SO3) for the construction of the novel 2D polymer [{Cp*Fe(μ4,η5:1:1:1‐P5)}{Cu(CF3SO3)}]n (2) and the unprecedented nanosphere (CH2Cl2)1.4@[{CpBnFe(η5‐P5)}12{Cu(CF3SO3)}19.6] (3). The supramolecule 3 has a unique scaffold beyond the fullerene topology, with 20 copper atoms statistically distributed over the 30 vertices of an icosidodecahedron. Combinatorics was used to interpret the average disordered structure of the supramolecules. In this case, only two pairs of enantiomers with D5 and D2 symmetry are possible for bidentate bridging coordination of the triflate ligands. DFT calculations showed that differences in the energies of the isomers are negligible. The benzyl ligands enhance the solubility of 3, enabling NMR‐spectroscopic and mass‐spectrometric investigations.

The reaction between a preassembled Cu bimetallic molecular clip with a short intermetallic distance and a series of fully aliphatic cyano-capped ditopic linkers with increasing lengths was investigated. It is shown that, depending on the length of the ditopic linkers, the rational design of unprecedented supramolecular compact metallacycles containing fully aliphatic walls is possible. The specific preorganized molecular arrangement of the molecular clip used favors stabilizing interlinker London dispersion interactions, which allow, as the length of the linkers increases, the selective formation of discrete compact metallacycles at the expense of 1D coordination polymers. The generalizability of this approach was demonstrated by the reaction of fully aliphatic cyano-capped linkers with two other types of preassembled Cu bimetallic molecular clips that also had short intermetallic distances.

Although supramolecular chemistry is based on nature,i t has become an indispensable and fascinating field for the directed synthesis of certain assemblies.A mong these, discrete spherical supramolecules are particularly surprising as they can reach large dimensions,a pproaching the size of small proteins,a nd often provide defined inner cavities suitable for guest enclosure, [1] in addition to an unprecedented molecular symmetry and challenging solid-state chemistry, including crystallography.For their synthesis by self-assembly, non-covalent bonds in particular provide many advantages, such as the combination of strength and reversibility.A st he donor-acceptor bonding is directional, rational design becomes possible by variation of the symmetry and geometry of the corresponding building blocks.[2] In contrast to sixfoldsymmetric building blocks,w hich form 2D layers,t he use of pentatopic nodes allows for bending and leads to unique spherical aggregates.Aside from our approach based on using the planar fivefold-symmetric cyclo-P 5 ligand in [Cp R Fe(h 5 -P 5 )] (1;C p R = Cp* = h 5 -C 5 Me 5 (1a); Cp Bn = h 5 -C 5 (CH 2 Ph) 5 (1b); Cp BIG = h 5 -C 5 (4-nBuC 6 H 4 ) 5 (1c); Figure 1a), others, such as the Williams and Wright groups,a lso made use of such fivefold-symmetric starting materials,s uch as the pentakis(4-pyridyl)cyclopentadienide (Figure 1b) [3] and the pentakis(1-methylpyrazole)cyclopentadienide ligands (Figure 1c), [4] as well as [C 5 (CN) 5 ] À (Figure 1d), respectively.[5]In contrast to 1,a ll of these ligands contain nitrogen as the donating atom. Moreover,t he use of fivefold-symmetric building blocks distinguishes this research from other concepts developed by the groups of Fujita, [6] Stang, [7] Raymond, [8] and Nitschke, [1a, 9] which are all based on the coordination of N-and O-donor polytopic linkers to transition metals.In combination with various Lewis acidic metal cations, substituted pentaphosphaferrocenes [Cp R Fe(h 5 -P 5 )] have enabled the discovery and investigation of al arge variety of one-and two-dimensional polymers (coordination via 2, 3, or 4Patoms of the cyclo-P 5 ligand) [10] and discrete spherical compounds (mostly from the coordination of all 5Patoms) [11] over the last decade.S elected examples are depicted in Figure 2. Among these,the most symmetric supramolecule to

The reaction between a preassembled CuI bimetallic molecular clip with a short intermetallic distance and a series of fully aliphatic cyano‐capped ditopic linkers with increasing lengths was investigated. It is shown that, depending on the length of the ditopic linkers, the rational design of unprecedented supramolecular compact metallacycles containing fully aliphatic walls is possible. The specific preorganized molecular arrangement of the molecular clip used favors stabilizing interlinker London dispersion interactions, which allow, as the length of the linkers increases, the selective formation of discrete compact metallacycles at the expense of 1D coordination polymers. The generalizability of this approach was demonstrated by the reaction of fully aliphatic cyano‐capped linkers with two other types of preassembled CuI bimetallic molecular clips that also had short intermetallic distances.