Difference between revisions of "Carbon"

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{{stub}}
 
{{stub}}
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See: [[Gemstone like compound#Carbons versatility]]
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'''sp<sup>3</sup> allotropes:'''
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* [[Diamond]] (cubic)
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* [[Lonsdaleite]] (hexagonal)
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* [[Dialondeite]] (only accessible via [[piezomechanosynthesis]])
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* ...
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* O16 carbon – orthorhombic superhard – all-sp3 6 membered rings
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* Further less energetically stable all-sp3 allotropes: BC8, BC12, R16
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'''sp<sup>2</sup> allotropes:'''
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* Graphite (today single cystalline graphite is called HOPG for highly ordered pyrolytic graphite) <br>Future: POPMG for "perfectly ordered piezomechanosynthesized graphite.
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* Buckyballs (convex curvature; concave from inside) – weak molecular solids
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* Nanotubes (no curvature – flat rolled)
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* 3D meshes (hyperbolic curvature)
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* "penta graphene" (cairo pattern)
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* ...
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'''No exactly defined structure:'''
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* DLC diamond like carbon – [https://en.wikipedia.org/wiki/Diamond-like_carbon wikipedia]
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* Glassy carbon – [https://en.wikipedia.org/wiki/Glassy_carbon wikipedia]
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* Other form of amorphous carbon – [https://en.wikipedia.org/wiki/Amorphous_carbon wikipedia]
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* ...
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'''Exotic allotropes:'''
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* ...
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'''Binary compounds:'''
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* Silicon carbide SiC aka moissanite
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* Carbon nitrides: [[beta carbon nitride]] and cubic gauche carbon nitride
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----
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* Titanium carbide TiC aka titanium-khamrabaevite (cubic rock salt structure) Mohs 9-9.5 [[refractory]]
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* <small>Vanadium carbide VC (vanadium is not too common) vanadium-khamrabaevite <br>similar is: [https://en.wikipedia.org/wiki/Niobium_carbide NbC] and [https://en.wikipedia.org/wiki/Tantalum_carbide TaC] (Nb is not abundant, Ta is extremely rare)</small>
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* Zirconium cabide ZrC [https://en.wikipedia.org/wiki/Zirconium_carbide] (same structure but no natural mineral present) <br><small>similar is: [https://en.wikipedia.org/wiki/Hafnium(IV)_carbide HfC] (Hf is pretty rare)</small>
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* Iron carbide (this here is not cementite!!) iron-khamrabaevite (unknown stability, likely very hard)
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----
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* [https://en.wikipedia.org/wiki/Chromium_carbide Chromium_carbide] (various stoichiometric & structures - may point to useful covalent behavior) <br> Cr<sub>3</sub>C<sub>2</sub>  [https://en.wikipedia.org/wiki/Tongbaite Tongbaite] (refractory, Mohs 9.6; orthorhombic; 6.64g/ccm) Cr is not too abundant<br> [https://en.wikipedia.org/wiki/Cr23C6_crystal_structure Cr<sub>23</sub>C<sub>6</sub>]
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* Molybdenium carbide [https://de.wikipedia.org/wiki/Molybd%C3%A4ncarbid (de)] Mo<sub>2</sub>C (insoluble, two modifications α and β)  Mo is rather rare
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* [https://en.wikipedia.org/wiki/Tungsten_carbide Tungsten_carbide] (hexagonal, Mohs 9) W is rather rare
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----
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* Fe<sub>3</sub>C, Ni<sub>3</sub>C, Co<sub>3</sub>C  [https://en.wikipedia.org/wiki/Cohenite cohenite] endmembers (likely rather metallic, Mohs 5.5-6)
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----
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* copper and zinc are more electronegative => more covalent behavior => organometallic compounds
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----
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* Boron carbide B<sub>4</sub>C [https://de.wikipedia.org/wiki/Borcarbid] (boron is not too common)
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* Aluminium carbide [https://en.wikipedia.org/wiki/Aluminium_carbide] (reacts with water - releases methane gas CH<sub>4</sub>)
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* <small>Beryllium carbide [https://en.wikipedia.org/wiki/Beryllium_carbide Be<sub>2</sub>C] (very hard but reactive, toxic and rare)</small>
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* Magnesium carbide ??? - magnesium acetylide Mg<sub>2</sub>C<sub>3</sub> [https://de.wikipedia.org/wiki/Magnesiumcarbid (de wikipedia)]
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* Calcium carbide [https://en.wikipedia.org/wiki/Calcium_carbide CaC<sub>2</sub>] (an [https://en.wikipedia.org/wiki/Category:Acetylides acetylide] - reacts with water - releases ethyne gas C<sub>2</sub>H<sub>2</sub>)
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* TODO: La, Ce, (Li, Na, K)
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== Way harder than diamond ==
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Macroscopic (pre)tensions can increase resilience but not ultimate tensile strength. <br>
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In glass there internal tensions can increase resilience massively. <br>
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See Wikipedia on: [https://en.wikipedia.org/wiki/Prince_Rupert%27s_drop Prince Rupert's drop]s <br>
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These drops have their tail as weak spot and their shape is pre-given so they are of not much use beside a curiosity for sci-education. <br>
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In principle using advanced bottom up manufacturing it might be possible to toughen diamond a lot via internal tensions but leaving no weak spot.
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== Related ==
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* [[Diamondoid]]
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* [[Diamond]]
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* Elements in the same group: '''Carbon''', [[Silicon]], [[Germanium]], [[Tin]], [[Lead]]
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* [[Chemical element]]
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[[Category:Chemical element]]
  
 
== External links ==
 
== External links ==
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* Wikipedia: [https://en.wikipedia.org/wiki/Pi_bond Pi bond]
 
* Wikipedia: [https://en.wikipedia.org/wiki/Pi_bond Pi bond]
 
* Wikipedia: [https://en.wikipedia.org/wiki/Orbital_hybridisation Orbital hybridisation]
 
* Wikipedia: [https://en.wikipedia.org/wiki/Orbital_hybridisation Orbital hybridisation]
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* Wikipedia: [https://en.wikipedia.org/wiki/Carbide Carbides] and [https://en.wikipedia.org/wiki/Category:Carbides Category:Carbides]
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* Wikipedia: [https://en.wikipedia.org/wiki/Graphite_intercalation_compound Graphite_intercalation_compound] KC<sub>8</sub>
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* Wikipedia: [https://en.wikipedia.org/wiki/Metal_carbido_complex Metal_carbido_complex] (Transition metal carbides)
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* Wikipedia: [https://en.wikipedia.org/wiki/Metallocarbohedryne Metallocarbohedryne]

Latest revision as of 15:33, 1 June 2023

This article is a stub. It needs to be expanded.

See: Gemstone like compound#Carbons versatility

sp3 allotropes:

sp2 allotropes:

  • Graphite (today single cystalline graphite is called HOPG for highly ordered pyrolytic graphite)
    Future: POPMG for "perfectly ordered piezomechanosynthesized graphite.
  • Buckyballs (convex curvature; concave from inside) – weak molecular solids
  • Nanotubes (no curvature – flat rolled)
  • 3D meshes (hyperbolic curvature)
  • "penta graphene" (cairo pattern)
  • ...

No exactly defined structure:

Exotic allotropes:

  • ...

Binary compounds:

  • Silicon carbide SiC aka moissanite
  • Carbon nitrides: beta carbon nitride and cubic gauche carbon nitride
  • Titanium carbide TiC aka titanium-khamrabaevite (cubic rock salt structure) Mohs 9-9.5 refractory
  • Vanadium carbide VC (vanadium is not too common) vanadium-khamrabaevite
    similar is: NbC and TaC (Nb is not abundant, Ta is extremely rare)
  • Zirconium cabide ZrC [1] (same structure but no natural mineral present)
    similar is: HfC (Hf is pretty rare)
  • Iron carbide (this here is not cementite!!) iron-khamrabaevite (unknown stability, likely very hard)
  • Chromium_carbide (various stoichiometric & structures - may point to useful covalent behavior)
    Cr3C2 Tongbaite (refractory, Mohs 9.6; orthorhombic; 6.64g/ccm) Cr is not too abundant
    Cr23C6
  • Molybdenium carbide (de) Mo2C (insoluble, two modifications α and β) Mo is rather rare
  • Tungsten_carbide (hexagonal, Mohs 9) W is rather rare
  • Fe3C, Ni3C, Co3C cohenite endmembers (likely rather metallic, Mohs 5.5-6)
  • copper and zinc are more electronegative => more covalent behavior => organometallic compounds
  • Boron carbide B4C [2] (boron is not too common)
  • Aluminium carbide [3] (reacts with water - releases methane gas CH4)
  • Beryllium carbide Be2C (very hard but reactive, toxic and rare)
  • Magnesium carbide ??? - magnesium acetylide Mg2C3 (de wikipedia)
  • Calcium carbide CaC2 (an acetylide - reacts with water - releases ethyne gas C2H2)
  • TODO: La, Ce, (Li, Na, K)

Way harder than diamond

Macroscopic (pre)tensions can increase resilience but not ultimate tensile strength.
In glass there internal tensions can increase resilience massively.
See Wikipedia on: Prince Rupert's drops
These drops have their tail as weak spot and their shape is pre-given so they are of not much use beside a curiosity for sci-education.
In principle using advanced bottom up manufacturing it might be possible to toughen diamond a lot via internal tensions but leaving no weak spot.

Related

External links

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