Octanitrocubane (molecular formula: C
8(NO
2)
8) is a proposed
high explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...
that, like
TNT
Troponin T (shortened TnT or TropT) is a part of the troponin complex, which are proteins integral to the contraction of skeletal and heart muscles. They are expressed in skeletal and cardiac myocytes. Troponin T binds to tropomyosin and helps ...
, is shock-insensitive (not readily
detonate
Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves wit ...
d by shock). The octanitrocubane molecule has the same
chemical structure
A chemical structure of a molecule is a spatial arrangement of its atoms and their chemical bonds. Its determination includes a chemist's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target m ...
as
cubane
Cubane is a synthetic hydrocarbon compound with the Chemical formula, formula . It consists of eight carbon atoms arranged at the corners of a Cube (geometry), cube, with one hydrogen atom attached to each carbon atom. A solid crystalline substanc ...
(C
8H
8) except that each of the eight
hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
atoms is replaced by a
nitro group
In organic chemistry, nitro compounds are organic compounds that contain one or more nitro functional groups (). The nitro group is one of the most common explosophores (functional group that makes a compound explosive) used globally. The nit ...
(NO
2). As of 1998, octanitrocubane had not been produced in quantities large enough to test its performance as an explosive.
It is, however, not as powerful an explosive as once thought, as the high-density theoretical crystal structure has not been achieved. For this reason,
heptanitrocubane, the slightly less nitrated form, is believed to have marginally better performance, despite having a worse oxygen balance.
Octanitrocubane is thought to have 20–25% greater performance than
HMX (octogen). This increase in power is due to its highly expansive breakdown into CO
2 and N
2, as well as to the presence of strained chemical bonds in the molecule which have stored
potential energy
In physics, potential energy is the energy of an object or system due to the body's position relative to other objects, or the configuration of its particles. The energy is equal to the work done against any restoring forces, such as gravity ...
. In addition, it produces no water vapor upon combustion, making it less visible, and both the chemical itself and its decomposition products (
nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...
and
carbon dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...
) are considered to be non-toxic.
Octanitrocubane was first synthesized by
Philip Eaton (who was also the first to synthesize cubane in 1964) and Mao-Xi Zhang at the
University of Chicago
The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...
in 1999, with the structure proven by crystallographer Richard Gilardi of the
United States Naval Research Laboratory
The United States Naval Research Laboratory (NRL) is the corporate research laboratory for the United States Navy and the United States Marine Corps. Located in Washington, DC, it was founded in 1923 and conducts basic scientific research, appl ...
.
Synthesis
Although octanitrocubane is predicted to be one of the most effective explosives, the difficulty of its synthesis inhibits practical use. Philip Eaton's synthesis was difficult and lengthy, and required
cubane
Cubane is a synthetic hydrocarbon compound with the Chemical formula, formula . It consists of eight carbon atoms arranged at the corners of a Cube (geometry), cube, with one hydrogen atom attached to each carbon atom. A solid crystalline substanc ...
(rare to begin with) as a starting point. As a result, octanitrocubane is more valuable, gram for gram, than
gold
Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...
.

A proposed path to synthesis is the cyclotetramerization of the as yet undiscovered and presumably highly unstable
dinitroacetylene.
See also
*
Octaazacubane
Octaazacubane is a hypothetical explosive allotrope of nitrogen with formula N8, whose molecules have eight atoms arranged into a cube. (By comparison, nitrogen usually occurs as the diatomic molecule N2.) It can be regarded as a cubane-type clu ...
(N8)
*
4,4'-Dinitro-3,3'-diazenofuroxan (DDF)
*
Hexanitrobenzene
Hexanitrobenzene, also known as HNB, is a nitrobenzenes, nitrobenzene compound in which six Nitro compound, nitro groups are bonded to all six positions of a central benzene ring. It is a high-density explosive compound (chemistry), compound with ...
(HNB)
*
Hexanitrohexaazaisowurtzitane
Hexanitrohexaazaisowurtzitane, also called HNIW and CL-20, is a polycyclic compound, polycyclic nitroamine explosive with the formula . It has a better Redox, oxidizer-to-fuel ratio than conventional HMX or RDX. It releases 20% more energy than tr ...
(HNIW)
*
HHTDD (Hexanitrohexaazatricyclododecanedione)
*
Relative effectiveness factor
References
{{reflist
External links
"American Chemical Society lauds difficult synthesis of new compound" (by Philip Eaton), March 20, 2001
Explosive chemicals
Nitro compounds
Substances discovered in the 1990s