Octaazacubane is a hypothetical

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 expl ...

allotrope Allotropy or allotropism () is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements. Allotropes are different structural modifications of an element: the ...

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

with formula N₈, whose

molecule A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...

s have eight

atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, and ...

s arranged into a

cube In geometry, a cube is a three-dimensional solid object bounded by six square faces, facets or sides, with three meeting at each vertex. Viewed from a corner it is a hexagon and its net is usually depicted as a cross. The cube is the only r ...

. (By comparison, nitrogen usually occurs as the

diatomic Diatomic molecules () are molecules composed of only two atoms, of the same or different chemical elements. If a diatomic molecule consists of two atoms of the same element, such as hydrogen () or oxygen (), then it is said to be homonuclear. Ot ...

molecule N₂.) It can be regarded as a

cubane-type cluster A cubane-type cluster is an arrangement of atoms in a molecular structure that forms a cube. In the idealized case, the eight vertices are symmetry equivalent and the species has Oh symmetry. Such a structure is illustrated by the hydrocarbon cub ...

, where all eight corners are nitrogen atoms bonded along the edges. It is predicted to be a

metastable molecule In chemistry and physics, metastability denotes an intermediate energetic state within a dynamical system other than the system's state of least energy. A ball resting in a hollow on a slope is a simple example of metastability. If the ball i ...

, in which despite the

thermodynamic Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of ther ...

instability caused by bond strain, and the high energy of the N–N single bonds, the molecule remains kinetically stable for reasons of

orbital symmetry Molecular symmetry in chemistry describes the symmetry present in molecules and the classification of these molecules according to their symmetry. Molecular symmetry is a fundamental concept in chemistry, as it can be used to predict or explain m ...

Explosive and fuel

Octaazacubane is predicted to have an

energy density In physics, energy density is the amount of energy stored in a given system or region of space per unit volume. It is sometimes confused with energy per unit mass which is properly called specific energy or . Often only the ''useful'' or extract ...

(assuming decomposition into N₂) of 22.9 MJ/ kg, which is over 5 times the standard value of

TNT Trinitrotoluene (), more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagen ...

. It has therefore been proposed (along with other exotic nitrogen allotropes) as an

, and as a component of high performance

rocket fuel Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical ...

. Its

velocity of detonation Explosive velocity, also known as detonation velocity or velocity of detonation (VoD), is the velocity at which the shock wave front travels through a detonated explosive. Explosive velocities are always faster than the local speed of sound in the ...

is predicted to be 15,000 m/s, much (48.5%) more than

octanitrocubane Octanitrocubane (molecular formula: C8(NO2)8) is a high explosive that, like Trinitrotoluene, TNT, is shock-insensitive (not readily detonated by shock). The octanitrocubane molecule has the same chemical structure as cubane (C8H8) except that ea ...

, the fastest known nonnuclear explosive. A prediction for

cubic gauche nitrogen Solid nitrogen is a number of solid forms of the element nitrogen, first observed in 1884. Solid nitrogen is mainly the subject of academic research, but low-temperature, low-pressure solid nitrogen is a substantial component of bodies in the ou ...

energy density is 33 MJ/ kg, exceeding octaazacubane by 44%, though a more recent one is of 10.22 MJ/kg, making it less than half of octaazacubane.

References

External links

*{{Commons category-inline Explosive chemicals Hypothetical chemical compounds Allotropes of nitrogen

Explosive and fuel

See also

References

External links