Atrane

[1] Various atranes are named depending on the central element, e.g. "silatrane" (E = silicon); "boratrane" (E = boron); "phosphatrane" (E = phosphorus), etc.

[2] Silatranes exhibit unusual properties as well as biological activity in which the coordination of nitrogen to silane plays an important role.

The transannular coordinate bond in atranes can be stretched (quasiatranes) and even broken (proatranes,) by controlling their stereoelectronic properties.

The strength of the transannular interaction depends on the electronegativity of the participating atoms and the size of the rings.

Proazaphosphatrane is a very strong non-ionic base and is utilized in various types of organic synthesis as an efficient catalyst.