Tetrahedrane properties

The polycyclic cage compounds of Group 14 elements heavier than carbon (i.e. tetrahedranes, cubanes, prismanes, etc.) have fascinated chemists for a long time because of their unique structures and expected unusual physico-chemical properties and reactivity1. It was quite reasonable to assume that such exotic compounds could possess properties... 

Structure oriented design refers to projects aimed at the creation of molecules with unusual structural characteristics not necessarily related to some useful property. This brings to mind a plethora of classical studies such as the previously discussed syntheses of cyclooctatetraene, Dewar benzene, or asterane. More recent examples include the syntheses of the dodecahedrane and tetrahedrane frameworks. The goal of the investigations in this area is first to invent and then to synthesize certain non-trivial molecules having unique structural features. This uniqueness very often refers to a novelty in the general shape of the molecules (as for dodecahedrane or catenanes), which are otherwise constructed in accordance with the classical concepts of structural theory. At the same time, quite a number of unprecedented structures have... 

P. Politzer and J. M. Seminario,/, Phys. Chem., 93,588 (1989). A Computational Determination of the Structures and Some Properties of Tetrahedrane, Prismane, and Some of Their Aza Analogs. 

Exotic chemistry the concatenation of strained rings in tetrahedrane may not ordy thwart conventional routes to its realization, but could also confer unusual properties, such as anomalous reactivity, acidity or basicity, and ionization energy, to name some possibilities. 

Other than its kinetic and thermodynamic stability (above), several properties of tetrahedrane are of interest, and can be readily calculated by current computational chemical techniques. Here we will look at four strain, ionization energy, acidity, and basicity. 

To obtain further insights into the formation of 1, we studied its reactivity. The already mentioned high thermostability of 1 points towards special stability associated with the tetrahedral Si4 framework. Thus, the following question may be formulated with Fig. 4. Is the existence of an isolable modification of silicon a possibility, in which Si4 tetrahedranes take the positions of carbon atoms in diamond I wonder if the generation of such a material would be a challenge to solid-state chemists and silicon manufacturers. Such a material would certainly show unexpected properties. 

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