List of Allotropes and Forms
Allotropes are in bold.
| Formula/name | Common name | Other names | Notes |
|---|---|---|---|
| S2 | disulfur | A diatomic gas with a triplet ground state like dioxygen. | |
| S3 | trisulfur | A cherry red triatomic gas with a bent ozone-like structure. | |
| S4 | tetrasulfur | Structure not determined but calculations indicate it to be cyclo-S4. | |
| cyclo-S5 | cyclo-pentasulfur | Not yet isolated, only detected in sulfur vapour. | |
| cyclo-S6 | ρ-sulfur | cyclo-hexasulfur, "ε-sulfur", "Engel's" sulfur, "Aten's sulfur" | The ring adopts a chair form in the solid. |
| cyclo-S6/cyclo-S10 adduct | A mixed crystal with alternating layers of cyclo-S6 and cyclo-S10. | ||
| cyclo-S7 | α-, β-, γ-, δ- cycloheptasulfur | Four forms known, two(γ-, δ- ) characterized. | |
| cyclo-S8 | α-sulfur | "orthorhombic sulfur" "rhombic sulfur", "flowers of sulfur", "roll sulfur" "milk of sulfur", "Muthmann's sulfur I" | Yellow solid consisting of S8 puckered rings. The thermodynamically stable form at ordinary temperatures. |
| cyclo-S8 | β-sulfur | "monoclinic sulfur" "prismatic sulfur" "Muthmann's sulfur II" | Yellow crystalline solid, consisting of S8 puckered rings. Only stable above 95.6 °C, it reverts to α-sulfur at room temperature. |
| cyclo-S8 | γ-sulfur | "nacreous sulfur" "mother of pearl sulfur" "Gernez’s sulfur" or "Muthmann's sulfur III". | Light yellow solid, crystal monoclinic, consisting of S8 puckered rings. Found in nature as the rare mineral rosickyite. |
| cyclo-Sn n = 9–15, 18, 20 |
cyclo-(nona; deca; undeca; dodeca; trideca; tetradeca; pentadeca; octadeca; eicosa)sulfur | Pure forms all allotropes, cyclo-S9 has four forms, cyclo-S18 has two forms. Generally synthesised rather than obtained by treatment of another form of elemental sulfur. | |
| catena-Sx | fibrous (ψ) sulfur | Well characterized, contains parallel helical sulfur chains and is difficult to obtain pure. | |
| catena-Sx | lamina sulfur | Not well characterized, contains helical chains partially crossed. | |
| amorphous sulfur | Quenched molten sulfur plastic sulfur at first crystallises to amorphous or glassy sulfur. Consists of a mixture of catena sulfur and cyclo sulfur. | ||
| insoluble sulfur | Quenched liquid sulfur with soluble species extracted with CS2. Sometimes called polymeric sulfur, μ-S or ω-S. | ||
| φ-sulfur | A mixture of allotropic ψ-sulfur and cyclo forms mainly γ-cyclo-S8. | ||
| ω-sulfur | insoluble sulfur | A mixture of chains with a minimum of soluble species. | |
| λ-sulfur | Light yellow mobile liquid formed when β-sulfur first melts at 119.6 °C. Consists of S8 rings. | ||
| μ-sulfur | The dark-coloured viscous liquid formed when π-sulfur is heated and the solid when cooled. Contains a mixture of polymeric chains. | ||
| π-sulfur | Dark-coloured liquid that develops as λ-sulfur is left molten. Contains mixture of Sn rings. | ||
| High-pressure forms of α-sulfur | S-II, S-III, S-IV, S-V and others | Four high-pressure phases (at ambient temperature) including two that are metallic and become superconducting at low temperature and some additional phases photo-induced below 20–30 GPa. | |
Read more about this topic: Allotropes Of Sulfur
Famous quotes containing the words list of, list and/or forms:
“Religious literature has eminent examples, and if we run over our private list of poets, critics, philanthropists and philosophers, we shall find them infected with this dropsy and elephantiasis, which we ought to have tapped.”
—Ralph Waldo Emerson (1803–1882)
“Love’s boat has been shattered against the life of everyday. You and I are quits, and it’s useless to draw up a list of mutual hurts, sorrows, and pains.”
—Vladimir Mayakovsky (1893–1930)
“Ring out a slowly dying cause,
And ancient forms of party strife;
Ring in the nobler modes of life,
With sweeter manners, purer laws.”
—Alfred Tennyson (1809–1892)