thumb|right|The atrane structure Atranes are a class of tricyclic molecules that are fused to a common central bond. Unlike the propellanes, the central bond is a transannular dative bond from a Lewis base—typically nitrogen—at one bridgehead to a Lewis acidic atom such as silicon or boron at the other bridgehead. Each of the three rings is therefore heterocyclic. Each of the rings is typically five atoms, or sometimes six atoms. The name "atrane" was first proposed by .
thumb|right|The atrane structure Atranes are a class of tricyclic molecules that are fused to a common central bond. Unlike the propellanes, the central bond is a transannular dative bond from a Lewis base—typically nitrogen—at one bridgehead to a Lewis acidic atom such as silicon or boron at the other bridgehead. Each of the three rings is therefore heterocyclic. Each of the rings is typically five atoms, or sometimes six atoms. The name "atrane" was first proposed by .
== Nomenclature == thumb|right|170px|Ball-and-stick model of the [[allyl silatrane molecule]] thumb|upright|right|Fe(0)-N2 complex based on atrane framework. Various atranes are named depending on the central element, e.g. "silatrane" (E = silicon); "boratrane" (E = boron); "phosphatrane" (E = phosphorus), stannatrane (E = tin), etc. It is also proposed that when Y = nitrogen, the prefix "aza" be inserted before element + "atrane" (azasilatrane, for example) because atranes wherein E = silicon and Y = oxygen have been referred to as just "silatranes".
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).