allotropy

en-noun

allotropy (countable and uncountable, plural allotropies)

(chemistry) A property, exhibited by some elements, of existing in multiple forms with different atomic structures.


allotropic

Graphite and diamond are allotropic forms of carbon.

(chemistry) Describing a form of an element that exhibits allotropy.


allotrope

Back-formation from allotropy, as allo- + -trope, from Ancient Greek ἄλλος (állos, “other”), and τρόπος (trópos, “way, manner”).

Ozone (O₃) is an allotrope of oxygen, normally O₂
Note: Different structural forms of a compound are isomers.

(chemistry) Any form of an element that has a distinctly different molecular structure to another form of the same element, with different physical properties and often different chemical properties.

al·lòtrop

element form of different molecular structure to another form of the same element


ozone

From German Ozon, coined 1840 by Christian Friedrich Schönbein, from Ancient Greek ὄζον (ózon), neuter participle of ὄζω (ózō, “I smell”), in reference to its pungent odour.
The “fresh air” sense is from an erroneous former belief that seaweed contains and releases ozone.

Lightning flashed again, the thunder came a second later. It rained harder. The smell of ozone was strong. You could feel the charge in the air.

2018, Nnedi Okorafor, Who Fears Death, HarperVoyager, page 334:

(inorganic chemistry) An allotrope of oxygen (symbol O₃) having three atoms in the molecule instead of the usual two; it is a toxic gas, generated from oxygen by electrical discharge.

A patent obtained in England, and specified far from clearly, for obtaining ozone by boiling seaweed,†† may be mentioned as a curiosity, and also the credulity with which ozone-baths, prepared in this manner, find a ready sale, in spite of, or perhaps rather on account of, their high price.

1875, William Crookes, The Chemical News, page 99:

To Ramsgate baths she sped, in quest / Of seaweed and ozone ; / For seaweed and ozone were best, / They said, to give her tone.

1888, L. T. Meade, A. Balfour Symington, Edwin Oliver, Atalanta, volume 1, page 674:

It's got the lot: fresh sea air, ozone, seaweed. You could cut the air with a knife.

2007, Robert Douglas, Tales of the Unexpected: Somewhere to Lay My Head, unnumbered page:

(British, informal) Fresh air, especially that breathed at the seaside and smelling of seaweed.


yellow phosphorus

white phosphorus
white phosphorus#English


black phosphorus

The least reactive of the allotropes of phosphorus; it has no significant commercial use.

phosphorene

the graphene analogous derivative of black phosphorus, where black phosphorus is a graphite analog


red phosphorus

Coordinate term: white phosphorus

(chemistry) A stable allotrope of phosphorus, used in the manufacture of safety matches, pesticides, etc.


white phosphorus

The IDF spokesperson provided no comment on whether it had halted the practice, or the reported use of white phosphorus in Gaza, a densely populated area and home to more than 2 million people.

2023 October 9, Ruth Michaelson, Ben Doherty, “Israel ‘going on the offensive’ after retaking territories overrun by Hamas”, in The Guardian, →ISSN:

phosphorus pentoxide
phosphorus pentoxide

(chemistry) The most common allotrope of phosphorus; a yellow-white waxy solid that is insoluble in water and spontaneously combusts on exposure to air to form clouds of phosphorus pentoxide; used as a military smokescreen and as an incendiary weapon.


dilithium

LL-Q1860 (eng)-Flame, not lame-dilithium.wav

(inorganic chemistry) The diatomic molecule Li₂ found in the gas phase.


icy noctiluca

Buy I having returned to the Author both his own Papers, and my Version of them, in one Roll, it unfortunately hapned, that before the Icy Noctiluca was printed off, there broke out in the Night a great Fire […]

1680, Robert Boyle, New Experiments and Observations made upon the Icy Noctiluca:


delta iron

delta iron (usually uncountable, plural delta irons)


dihydrogen

LL-Q1860 (eng)-Flame, not lame-dihydrogen.wav

(inorganic chemistry) The hydrogen molecule H₂.


dinitrogen

(chemistry) the normal nitrogen molecule having two atoms

(chemistry, used in combination) two atoms of nitrogen as part of some other compound


dioxygen

(inorganic chemistry) the normal allotrope of oxygen having two atoms per molecule; O₂

(inorganic chemistry, in combination) two atoms of oxygen in a molecule


tetraoxygen

(chemistry) an allotrope of oxygen having four atoms in each molecule instead of the normal two; only stable under very high pressures


disulfur

(inorganic chemistry, in combination) Two atoms of sulfur in a compound.


tetrasulfur

(chemistry) (in combination) Four atoms of sulfur in a molecule


allotropism

(chemistry) The ability (of an element) to exist in more than one physical form without change of state.


allotropical

en-adj

allotropical (comparative more allotropical, superlative most allotropical)

more allotropical (comparative)
most allotropical (superlative)

Graphite and diamond are allotropical forms of carbon.

(chemistry) (rare) Of or pertaining to an element that exhibits allotropy.


dirubidium

(inorganic chemistry, in combination) Two atoms of rubidium in a compound


diprotium

(inorganic chemistry) Normal molecular hydrogen H₂


trioxygen

(inorganic chemistry) ozone (the triatomic allotrope of oxygen)


allotriomorphic

allotriomorphic (comparative more allotriomorphic, superlative most allotriomorphic)

more allotriomorphic (comparative)
most allotriomorphic (superlative)


austenite

After William Chandler Roberts-Austen (1843-1902).

A solid solution of carbon or ferric carbide in iron that exists in steel at high temperatures.


silicene

(organic chemistry) Any short-lived, reactive species R₂Si: analogous to carbenes.


gamma iron

(metallurgy) An allotrope of iron which is stable at high temperatures. It is used in the manufacture of austenite.


germanene

Calculating the complex dielectric function for optical interband transitions we show that the two-dimensional crystals silicene and germanene possess the same low-frequency absorbance as graphene.

2012, Friedhelm Bechstedt, Lars Matthes, Paola Gori and Olivia Pulci, "Infrared absorbance of silicene and germanene", Appl. Phys. Lett. 100, 261906 (27 June 2012) p. 261906-1

We present first-principles studies of the optical absorbance of the group IV honeycomb crystals graphene, silicene, germanene, and tinene.

2013, Lars Matthes, Olivia Pulci, Friedhelm Bechstedt, “Massive Dirac quasiparticles in the optical absorbance of graphene, silicene, germanene, and tinene”, in Journal of Physics: Condensed Matter, 25 #39 (4 September 2013) 395305 p. 395305-1:

After the successful synthesis of silicene in 2012, which was followed by a surge of studies on elemental, novel two-dimensional (2D) materials beyond graphene, a daunting quest was to obtain germanene, the germanium-based analogue of graphene, already predicted to possibly exist in 2009.

2014, M E Dávila, L Xian, S Cahangirov, A Rubio and G Le Lay, "Germanene: a novel two-dimensional germanium allotrope akin to graphene and silicene", New J. Phys. 16 095002 (9 September 2014) p. 095002-2

(inorganic chemistry) An allotrope of germanium that has a hexagonal, planar structure analogous to graphene


hexaferrum

(mineralogy) A hexagonal-dihexagonal dipyramidal yellowish steel gray mineral containing iridium, iron, osmium, and ruthenium.

A hexagonal-close-packed allotrope of iron, stable only at high pressure


octasulfur

(inorganic chemistry) The most common allotrope of sulfur (S₈), containing eight atoms in a ring.


hexazine

(inorganic chemistry) The allotrope of nitrogen (N₆) composed of a ring of six atoms, arranged like those of benzene


octaoxygen

A red allotrope of oxygen, O₈, that is stable only under very high pressures


silicyne

an allotrope of silicon, consisting of a long chain of silicon atoms linked together with either (1) disilene units [ ...=Si=Si=Si=...] or (2) disilyne units [ ...–Si≡Si–Si≡Si–... ]


stanene

Blend of stannum + graphene (stannum + -ene) from Latin stannum (“tin”) and graphene, due to the analogous situation of tin in the material to carbon in graphene, being a two-dimensional layer one-atom thick.

topological insulator
topological insulator

(inorganic chemistry) a two-dimensional layer of tin one-atom thick, which is a topological insulator (conducting electricity only along its edges).


borospherene

B₄₀, a hollow cage shaped molecule composed of 40 boron atoms, similar to C₆₀ buckyballs

by extension, the boron allotrope, the class of spheroidal boron allotropic molecules.


borophene

From boro- + graphene. Blend of boron + graphene.

an allotrope of boron, the class of quasiplanar and planar one-atom-thick molecular sheets of boron atoms, similar to carbon's graphene structure


phosphorene

From phosphorus + -ene. By analogy with graphene.

(inorganic chemistry) A semiconductor allotropic form of phosphorus in the form of two-dimensional layers, with a quasi-flat hexagonal honeycomb structure of derivative of black phosphorus


white tin

β-tin, a body-centered tetragonal crystalline tin, an allotrope of tin


metallic hydrogen

From metallic + hydrogen. From hydrogen being like a metal, having free-roaming electrons that support electrical conductivity.

a degenerate matter phase of hydrogen that is electrically conductive; formed under extreme pressure


dark hydrogen

From being a state of matter which neither transmits nor reflects visible light, but can transmit infrared.

One particular species of these candidates seems to be not dark at all: so-called dark hydrogen masses located in the optical Galactic disk.

2000, F. Combes, G. Pineau des Forets, Molecular Hydrogen in Space, →ISBN, page 48:

The over-unity energy production could be due to a gradual transformation of hydrogen to dark hydrogen in the same state as in water.

2007, Florentin Smarandache, V. Christianto, Hadron models and related New Energy issues, →ISBN, page 96:

However, the rates of dark hydrogen production were relatively low.

2013, Tokio Ohta, Solar-Hydrogen Energy Systems, →ISBN:

(physics) A state of hydrogen that is poorly electrically conductive (much less conductive than metallic hydrogen).


trideuterium

A molecule composed of three deuterium atoms, or matter composed of such molecules. Symbol: ²H₃ or D₃.


dideuterium

A molecule composed of two deuterium atoms, or matter composed of such molecules. Symbol: ²H₂ or D₂.


trihydrogen

en-noun

trihydrogen (countable and uncountable, plural trihydrogens)

A cation triangular molecule composed of three hydrogen atoms, or matter composed of such molecules. Symbol: H₃⁺.


octaazacubane

octaazacubane (countable and uncountable, plural octaazacubanes)

From octa- + aza- + cubane. From cube + -ane.

A theoretical molecule composed of eight (8) nitrogen atoms only, in a cubic configuration, with each nitrogen (N) atom being a vertex on the cube, and bonding to three other nitrogens at the nearest three other vertexes. This is theorized to be the high explosive with the highest velocity, the most explosive non-nuclear explosive. It is an allotrope of nitrogen, and an analogue of the organic molecule cubane; and an isomer of octanitrogen (N₈).