Cubane-type cluster

A cubane-type cluster is an arrangement of atoms in a molecular structure that forms a cube. In the idealized case, the eight vertices are symmetry equivalent and the species has Oh symmetry. Such a structure is illustrated by the hydrocarbon cubane. With chemical formula , cubane has carbon atoms at the corners of a cube and covalent bonds forming the edges. Most cubanes have more complicated structures, usually with nonequivalent vertices. They may be simple covalent compounds or macromolecular or supramolecular cluster compounds. Other compounds having different elements in the corners, various atoms or groups bonded to the corners are all part of this class of structures. Inorganic cubane-type clusters include selenium tetrachloride, tellurium tetrachloride, and sodium silox. Cubane clusters are common throughout bioinorganic chemistry. Ferredoxins containing [Fe4S4] iron–sulfur clusters are pervasive in nature. The four iron atoms and four sulfur atoms form an alternating arrangement at the corners. The whole cluster is typically anchored by coordination of the iron atoms, usually with cysteine residues. In this way, each Fe center achieves tetrahedral coordination geometry. Some [Fe4S4] clusters arise via dimerization of square-shaped [Fe2S2] precursors. Many synthetic analogues are known including heterometallic derivatives. DasCubane.png|[[Das cubane]], [CoO(OAc)py]4 (OAc = [[acetate]]; py = [[pyridine]]){{cite journal |doi=10.1021/ic7011759|title=Synthesis, Structure, Spectral and Electrochemical Properties, and Catalytic Use of Cobalt(III)−Oxo Cubane Clusters|year=2007|last1=Chakrabarty|first1=Rajesh|last2=Bora|first2=Sanchay J.|last3=Das|first3=Birinchi K.|journal=Inorganic Chemistry|volume=46|issue=22|pages=9450–9462|pmid=17910439}} Fe4S4.svg|Ferredoxin (4Fe-4S-cubane) Oxygen Evolving Complex Crystal structure to 1.9 Angstrom Resolution.png|CaMn3O4 cubane in [[Photosystem II]].