Cuboctahedron

About: Cuboctahedron is a research topic. Over the lifetime, 159 publications have been published within this topic receiving 4174 citations. The topic is also known as: heptaparallelohedron & Vector Equilibrium.

Porous Metal−Organic Polyhedra: 25 Å Cuboctahedron Constructed from 12 Cu2(CO2)4 Paddle-Wheel Building Blocks

Abstract: At present there are at least two challenges that must be addressed for larger and more complex systems to be realized. First, single crystals of large molecules are difficult to obtain, thus precluding their full structural characterization; second, design of rigid entities that maintain their structure in the absence of guests in order to allow for reversible access to the voids as well as chemical functionalization of their voids and outside surface remains largely unexplored. Given these challenges and considering our recent work on metal -organic frameworks (MOFs), where we have demonstrated the use of secondary building units (SBUs) as means to the construction of rigid networks with permanent porosity, we sought to use the paddle-wheel cluster adopted by copper(II) acetate, Cu2(CO2)4, as a rigid SBU for addressing these challenges. Significantly, the assembly of such SBUs with polytopic carboxylate linkers generated rigid porous frameworks with open metal sites where it is possible to functionalize the pores with different ligands. 10 The possible structures in which square SBUs (such as the paddle-wheel) are linked by identical links are derived from fourconnected nets in which there is a planar (or near planar) vertex arrangement where all links are equivalent (quasiregular). 11

Self-assembly of nanoscale cuboctahedra by coordination chemistry

Abstract: Self-assembled polyhedral structures are common in biology. The coats of many viruses, for example, have a structure based on icosahedral symmetry. The preparation of synthetic polyhedral molecular assemblies represents a challenging problem, but supramolecular chemistry has now advanced to the point where the task may be addressed. Macromolecular and supramolecular entities of predefined geometric shape and with well-defined internal environments are potentially important for inclusion phenomena, molecular recognition and catalysis. Here we report the use of self-assembly of molecular units driven by coordination to transition-metal ions to prepare a cuboctahedron from 20 tridentate and bidentate subunits in a single step. The cuboctahedron is an archimedean semiregular polyhedron that combines square and triangular faces. Our self-assembled polyhedral capsules, characterized by NMR and electrospray mass spectrometry, are around 5 nanometres in diameter.

An M 18 L 24 stellated cuboctahedron through post-stellation of an M 12 L 24 core

Abstract: A molecular ‘stellated polyhedron’ with concave faces — constructed by extending the faces of its counterpart polyhedron until they intersect — has now been synthesized. Ligands that constitute the square faces of a metal–organic cuboctahedral cage were decorated with pendant side chains, which reversibly coordinate to additional metal centres to give rise to the stellated cage.

Ligand bridging-angle-driven assembly of molecular architectures based on quadruply bonded Mo-Mo dimers.

Abstract: A systematic exploration of the assembly of Mo2(O2C−)4-based metal−organic molecular architectures structurally controlled by the bridging angles of rigid organic linkers has been performed. Twelve bridging dicarboxylate ligands were designed to be of different sizes with bridging angles of 0, 60, 90, and 120° while incorporating a variety of nonbridging functional groups, and these ligands were used as linkers. These dicarboxylate linkers assemble with quadruply bonded Mo−Mo clusters acting as nodes to give 13 molecular architectures, termed metal−organic polygons/polyhedra with metal cluster node arrangements of a linear shape, triangle, octahedron, and cuboctahedron/anti-cuboctahedron. The syntheses of these complexes have been optimized and their structures determined by single-crystal X-ray diffraction. The results have shown that the shape and size of the resulting molecular architecture can be controlled by tuning the bridging angle and size of the linker, respectively. Functionalization of the lin...