|
A metallocarbohedryne (or met-car for short) is any one of a family of chemical compounds with the generic molecular formula , where M is a transition metal such as titanium, vanadium, zirconium, niobium, hafnium, molybdenum, chromium, or iron. These compounds have similar properties and a similar molecular structure, with the eight metal atoms at the corners of a somewhat diistorted cube, and the twelve carbon atoms, in pairs, placed diagonally across the faces of the cube. The structure can also be described as two intersecting tetrahedra of metal atoms, with the carbon atoms placed in pairs along the edges of one tetrahedron. They have been extensively studied in the gas phase, and sometimes dispersed in solid materials, but so far have not been produced in bulk or in solution.〔 Nevertheless, they have attracted interest because of their stability and symmetry, a relatively low ionization potential, delayed ionization, and possibly interesting magnetic properties.〔 Some authors suggest that they may eventually find applications in electronics and as catalysis.〔 The name is also used for the corresponding cations and anions .〔 The first papers used the name metallo-carbohedrene (with or without the hyphen) for this type of compound.〔〔〔 ==History== The earliest known member of this family is the anion , discovered by Guo, kerns, and Castleman in 1992 while researching the dehydrogenation of various hydrocarbons (including methane, acetylene, ethylene, benzene, and propylene) with titanium atoms, in the gas phase. Although fullerenes like were already known, that may have been the first cage-like molecule with metal atoms replacing carbon at some corners of the mesh. They observed that the cluster would bind eight ammonia molecules, indicating that the eight titanium atoms were exposed.〔 They also observed the analogous cations with vanadium, zirconium, or hafnium substituted for titanium, the corresponding neutral molecules, and the anion .〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Metallocarbohedryne」の詳細全文を読む スポンサード リンク
|