An Atrane is a tricyclic molecule

Molecule

A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

 with three five-membered rings. It has a transannular dative bond by a nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

 atom

Atom

The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...

, depicted as A. The name "atrane" was first proposed by Mikhail Grigorievich Voronkov.

Various atranes are named depending on the central element

Chemical element

A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...

, e.g. "silatrane" (E = silicon

Silicon

Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...

); "boratrane" (E = boron

Boron

Boron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...

); "phosphatrane" (E = phosphorus

Phosphorus

Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...

), 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

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

 have been referred to as just "silatranes".

Silatranes exhibit unusual properties as well as biological activity in which the coordination of nitrogen to silane

Silane

Silane is a toxic, extremely flammable chemical compound with chemical formula SiH4. In 1857, the German chemists and Friedrich Woehler discovered silane among the products formed by the action of hydrochloric acid on aluminum silicide, which they had previously prepared...

 plays an important role. Some derivatives such as phenylsilatrane

Phenylsilatrane

Phenylsilatrane is a convulsant chemical which has been used as a rodenticide....

 are highly toxic.

The transannular coordinate bond in atranes can be stretched (quasiatranes, B) and even broken (proatranes, C) by controlling their stereoelectronic properties. Proazaphosphatrane is a very strong non-ionic

Ion

An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...

 base

Base (chemistry)

For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...

 and is utilized in various types of organic

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

 synthesis

Chemical synthesis

In chemistry, chemical synthesis is purposeful execution of chemical reactions to get a product, or several products. This happens by physical and chemical manipulations usually involving one or more reactions...

 as an efficient catalyst.

In 2000, Robert R. Holmes and his co-workers reported a new class of silatranes that contain three six-membered rings and revealed that these atranes have weaker nitrogen donor interaction in comparison with corresponding ones bearing three five-membered rings. The degree of the interaction depends mainly on the electronegativity

Electronegativity

Electronegativity, symbol χ , is a chemical property that describes the tendency of an atom or a functional group to attract electrons towards itself. An atom's electronegativity is affected by both its atomic number and the distance that its valence electrons reside from the charged nucleus...

 effects of an exocyclic ligand

Ligand

In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...

.