Copper(I) acetylide: Difference between revisions

Copper(I) acetylide
Names
	IUPAC name Dicuprous acetylide
Identifiers
CAS Number	1117-94-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	14318114 ;
PubChem CID	19021056;
	InChI InChI=1S/C2.2Cu/c1-2;;/q-2;2+1 Key: SQDLRJMJSRRYGA-UHFFFAOYSA-N ; InChI=1/C2.2Cu/c1-2;;/q-2;2+1 Key: SQDLRJMJSRRYGA-UHFFFAOYAK;
	SMILES [C-]#[C-].[Cu+].[Cu+];
Properties
Chemical formula	C2Cu2
Molar mass	151.114 g·mol−1
Appearance	red-brown powder
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	explosive
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 1 mg/m3 (as Cu)
REL (Recommended)	TWA 1 mg/m3 (as Cu)
IDLH (Immediate danger)	TWA 100 mg/m3 (as Cu)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

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Copper(I) acetylide, Kupfercarbid or cuprous acetylide, is a chemical compound with the formula Cu₂C₂. Although never characterized by X-ray crystallography, the material has been claimed at least since 1856.^[2] One form is claimed to be a monohydrate with formula Cu
₂C
₂.H
₂O is a reddish-brown explosive powder.

Synthesis

Materials purported to be copper acetylide can be prepared by treating acetylene with a solution of copper(I) chloride and ammonia:

C₂H₂ (g) + 2 CuCl (s) → Cu₂C₂ (s) + 2 HCl (g)

This reaction produces a reddish solid precipitate.

Properties

When dry, copper acetylide is a heat and shock sensitive primary explosive, more sensitive than silver acetylide.^[3]

In acetylene manufacturing plants, copper acetylide is thought to form inside pipes made of copper or an alloy with high copper content, which may result in violent explosion.^[4] This led to abandonment of copper as a construction material in such facilities.^[5] Copper catalysts used in the chemical industry can also possess a degree of risk under certain conditions.^[6]

Reactions

Copper acetylide is the substrate of Glaser coupling for the formation of polyynes. In a typical reaction, a suspension of Cu
₂C
₂.H
₂O in an amoniacal solution is treated with air. The copper is oxidized to Cu²⁺
and forms a blue soluble complex with the ammonia, leaving behind a black solid residue. The latter has been claimed to consist of carbyne, an elusive allotrope of carbon:^[7]

Cu⁺
⁻C(≡C−C≡)_nC⁻ Cu⁺

This interpretation has been disputed.^[8]

Freshly prepared copper acetylide reacts with hydrochloric acid to form acetylene and copper(I) chloride. Samples that have been aged with exposure to air or to copper(II) ions liberate also higher polyynes H(−C≡C−)_nH, with n from 2 to 6, when decomposed by hydrochloric acid. A "carbonaceous" residue of this decomposition also has the spectral signature of (−C≡C−)_n chains. It has been conjectured that oxidation causes polymerization of the acetylide anions C²⁻
₂ in the solid into carbyne-type anions .C(≡C−C≡)_nC²⁻ or polycumulene-type anions C(=C=C=)_mC⁴⁻.^[2]

Thermal decomposition of copper acetylide in vacuum is not explosive and leaves copper as a fine powder at the bottom of the flask, while depositing a fluffy very fine carbon powder on the walls. On the basis of spectral data, this powder was claimed to be carbyne C(−C≡C−)_nC rather than graphite as expected.^[2]

Applications

Though not practically useful as an explosive due to high sensitivity, it is interesting as a curiosity because it is one of the very few explosives that do not liberate any gaseous products upon detonation.

The formation of copper acetylide when a gas is passed through a solution of copper(I) chloride is used as a test for the presence of acetylene.

Reactions between Cu⁺ and alkynes occur only if a terminal hydrogen is present (as it is slightly acidic in nature). Thus, this reaction is used for identification of terminal alkynes.

References

^ ^a ^b ^c NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).
^ ^a ^b ^c Franco Cataldo (1999), From dicopper acetylide to carbyne.Polymer International, volume 48, issue 1, pages 15-22. doi:10.1002/(SICI)1097-0126(199901)48:1
^ Cataldo, Franco; Casari, Carlo S. (2007). "Synthesis, Structure and Thermal Properties of Copper and Silver Polyynides and Acetylides". Journal of Inorganic and Organometallic Polymers and Materials. 17 (4): 641–651. doi:10.1007/s10904-007-9150-3. ISSN 1574-1443. S2CID 96278932.
^ "Mine Safety and Health Administration (MSHA) - Accident Prevention Program - Miner's Tips - Hazards of Acetylene Gas". Archived from the original on 2008-07-06. Retrieved 2008-06-08.
^ "Copper". Archived from the original on October 1, 2007. Retrieved February 8, 2013.
^ "The Safe Use of Copper -Containing Catalysts in Ethylene Plants". Retrieved 2008-06-08.
^ Franco Cataldo (1999), ' 'A study on the structure and electrical properties of the fourth carbon allotrope: carbyne. Polymer International, volume 44, issue 2, pages 191–200. doi:10.1002/(SICI)1097-0126(199710)44:2
^ H. Kroto (2010), Carbyne and other myths about carbon. RSC Chemistry World, November 2010.

[PGCH-1] NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).

[cataldo-2] Franco Cataldo (1999), From dicopper acetylide to carbyne.Polymer International, volume 48, issue 1, pages 15-22. doi:10.1002/(SICI)1097-0126(199901)48:1

[CataldoCasari2007-3] Cataldo, Franco; Casari, Carlo S. (2007). "Synthesis, Structure and Thermal Properties of Copper and Silver Polyynides and Acetylides". Journal of Inorganic and Organometallic Polymers and Materials. 17 (4): 641–651. doi:10.1007/s10904-007-9150-3. ISSN 1574-1443. S2CID 96278932.

[4] "Mine Safety and Health Administration (MSHA) - Accident Prevention Program - Miner's Tips - Hazards of Acetylene Gas". Archived from the original on 2008-07-06. Retrieved 2008-06-08.

[5] "Copper". Archived from the original on October 1, 2007. Retrieved February 8, 2013.

[6] "The Safe Use of Copper -Containing Catalysts in Ethylene Plants". Retrieved 2008-06-08.

[cataldo2-7] Franco Cataldo (1999), ' 'A study on the structure and electrical properties of the fourth carbon allotrope: carbyne. Polymer International, volume 44, issue 2, pages 191–200. doi:10.1002/(SICI)1097-0126(199710)44:2

[kroto-8] H. Kroto (2010), Carbyne and other myths about carbon. RSC Chemistry World, November 2010.

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[8]

@@ Line 12: / Line 12: @@
 | PubChem=19021056
 | SMILES=[C-]#[C-].[Cu+].[Cu+]
-|  ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
+| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
 | ChemSpiderID = 14318114
-|  InChI = 1/C2.2Cu/c1-2;;/q-2;2*+1
+| InChI = 1/C2.2Cu/c1-2;;/q-2;2*+1
-|  InChIKey = SQDLRJMJSRRYGA-UHFFFAOYAK
+| InChIKey = SQDLRJMJSRRYGA-UHFFFAOYAK
-|  StdInChI_Ref = {{stdinchicite|changed|chemspider}}
+| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
 | StdInChI = 1S/C2.2Cu/c1-2;;/q-2;2*+1
-|  StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
+| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
 | StdInChIKey = SQDLRJMJSRRYGA-UHFFFAOYSA-N
-  }}
+ }}
 |Section2={{Chembox Properties
 | C=2 | Cu=2
-| Appearance=
+| Appearance= red-brown powder
 | Density=
 | MeltingPt=
 | BoilingPt=
 | Solubility=
-  }}
+ }}
 |Section3={{Chembox Hazards
-| MainHazards= explosive, harmful
+| MainHazards= explosive
 | FlashPt=
 | AutoignitionPt =
 | PEL = TWA 1 mg/m<sup>3</sup> (as Cu)<ref name=PGCH>{{PGCH|0150}}</ref>
 | REL = TWA 1 mg/m<sup>3</sup> (as Cu)<ref name=PGCH/>
-| IDLH =  TWA 100 mg/m<sup>3</sup> (as Cu)<ref name=PGCH/>
+| IDLH = TWA 100 mg/m<sup>3</sup> (as Cu)<ref name=PGCH/>
-  }}
+ }}
 }}
-'''Copper(I) acetylide''', or '''cuprous acetylide''', is a [[chemical compound]] with the formula [[copper|Cu]]<sub>2</sub>[[carbon|C]]<sub>2</sub>.  Although never characterized by [[X-ray crystallography]], the material has been claimed at least since 1856.<ref name=cataldo/> One form is claimed to be a mono[[hydrate]] with formula {{chem|Cu|2|C|2}}.{{chem|H|2|O}}).  It is a reddish solid, that easily explodes when dry.
+'''Copper(I) acetylide''', '''Kupfercarbid''' or '''cuprous acetylide''', is a [[chemical compound]] with the formula [[copper|Cu]]<sub>2</sub>[[carbon|C]]<sub>2</sub>. Although never characterized by [[X-ray crystallography]], the material has been claimed at least since 1856.<ref name=cataldo/> One form is claimed to be a mono[[hydrate]] with formula {{chem|Cu|2|C|2}}.{{chem|H|2|O}} is a reddish-brown explosive powder.
 == Synthesis ==
 Materials purported to be copper acetylide can be prepared by treating [[acetylene]] with a solution of [[copper(I) chloride]] and [[ammonia]]:
-:C<sub>2</sub>H<sub>2</sub> + 2 CuCl → Cu<sub>2</sub>C<sub>2</sub> + 2 HCl
+:C<sub>2</sub>H<sub>2</sub> (g) + 2 CuCl (s) → Cu<sub>2</sub>C<sub>2</sub> (s) + 2 HCl (g)
 This reaction produces a reddish solid [[precipitate]].
 == Properties ==
-When dry, copper acetylide is a heat and shock sensitive [[high explosive]], more thermally sensitive than [[silver acetylide]].<ref name="CataldoCasari2007">{{cite journal|last1=Cataldo|first1=Franco|last2=Casari|first2=Carlo S.|title=Synthesis, Structure and Thermal Properties of Copper and Silver Polyynides and Acetylides|journal=Journal of Inorganic and Organometallic Polymers and Materials|volume=17|issue=4|year=2007|pages=641–651|issn=1574-1443|doi=10.1007/s10904-007-9150-3}}</ref>
+When dry, copper acetylide is a heat and shock sensitive [[primary explosive]], more sensitive than [[silver acetylide]].<ref name="CataldoCasari2007">{{cite journal|last1=Cataldo|first1=Franco|last2=Casari|first2=Carlo S.|title=Synthesis, Structure and Thermal Properties of Copper and Silver Polyynides and Acetylides|journal=Journal of Inorganic and Organometallic Polymers and Materials|volume=17|issue=4|year=2007|pages=641–651|issn=1574-1443|doi=10.1007/s10904-007-9150-3|s2cid=96278932}}</ref>
-Copper acetylide is thought to form inside pipes made of [[copper]] or an alloy with high copper content, which may result in violent explosion.<ref>{{cite web |url = http://www.msha.gov/Accident_Prevention/Tips/acetylenegas.htm |title = Mine Safety and Health Administration (MSHA) - Accident Prevention Program - Miner's Tips - Hazards of Acetylene Gas |accessdate = 2008-06-08 |archive-url = https://web.archive.org/web/20080706064005/http://www.msha.gov/Accident_Prevention/Tips/acetylenegas.htm |archive-date = 2008-07-06 |url-status = dead }}</ref> This was found to be the cause of explosions in acetylene plants, and led to abandonment of copper as a construction material in such plants.<ref>{{cite web|url=http://www.ilo.org/encyclopedia/?print&nd=857200158 |accessdate=February 8, 2013 |url-status=dead |archiveurl=https://web.archive.org/web/20071001010729/http://www.ilo.org/encyclopedia/?print&nd=857200158 |archivedate=October 1, 2007 }}</ref> Copper [[catalyst]]s used in [[petrochemistry]] can also possess a degree of risk under certain conditions.<ref>{{cite web|url = http://aiche.confex.com/aiche/s06/preliminaryprogram/abstract_43768.htm |title = The Safe Use of Copper -Containing Catalysts in Ethylene Plants |accessdate = 2008-06-08}}</ref>
+In acetylene manufacturing plants, copper acetylide is thought to form inside pipes made of [[copper]] or an alloy with high copper content, which may result in violent explosion.<ref>{{cite web |url = http://www.msha.gov/Accident_Prevention/Tips/acetylenegas.htm |title = Mine Safety and Health Administration (MSHA) - Accident Prevention Program - Miner's Tips - Hazards of Acetylene Gas |accessdate = 2008-06-08 |archive-url = https://web.archive.org/web/20080706064005/http://www.msha.gov/Accident_Prevention/Tips/acetylenegas.htm |archive-date = 2008-07-06 |url-status = dead}}</ref> This led to abandonment of copper as a construction material in such facilities.<ref>{{cite web|url=http://www.ilo.org/encyclopedia/?print&nd=857200158 |accessdate=February 8, 2013 |url-status=dead |archiveurl=https://web.archive.org/web/20071001010729/http://www.ilo.org/encyclopedia/?print&nd=857200158 |archivedate=October 1, 2007 |title=Copper}}</ref> Copper [[catalyst]]s used in the [[chemical industry]] can also possess a degree of risk under certain conditions.<ref>{{cite web|url = http://aiche.confex.com/aiche/s06/preliminaryprogram/abstract_43768.htm |title = The Safe Use of Copper -Containing Catalysts in Ethylene Plants |accessdate = 2008-06-08}}</ref>
 == Reactions ==
-Copper acetylide is the substrate of [[Glaser coupling]] for the formation of [[polyyne]]s.  In a typical reaction, a suspension of {{chem|Cu|2|C|2}}.{{chem|H|2|O}} in an [[ammonium|amoniacal]] solution is treated with air.  The copper is [[oxidized]] to {{chem|Cu|2+}} and forms a blue soluble [[coordination compound|complex]] with the [[ammonia]], leaving behind a black solid residue.  The latter has been claimed to consist of [[linear acetylenic carbon|carbyne]], an elusive [[allotrope]] of carbon:<ref name=cataldo2>Franco Cataldo (1999), ' 'A study on the structure and electrical properties of the fourth carbon allotrope: carbyne''. Polymer International, volume 44, issue 2, pages 191–200. {{doi|10.1002/(SICI)1097-0126(199710)44:2}}
+Copper acetylide is the substrate of [[Glaser coupling]] for the formation of [[polyyne]]s. In a typical reaction, a suspension of {{chem|Cu|2|C|2}}.{{chem|H|2|O}} in an [[ammonium|amoniacal]] solution is treated with air. The copper is [[oxidized]] to {{chem|Cu|2+}} and forms a blue soluble [[coordination compound|complex]] with the [[ammonia]], leaving behind a black solid residue. The latter has been claimed to consist of [[linear acetylenic carbon|carbyne]], an elusive [[allotrope]] of carbon:<ref name=cataldo2>Franco Cataldo (1999), ' 'A study on the structure and electrical properties of the fourth carbon allotrope: carbyne''. Polymer International, volume 44, issue 2, pages 191–200. {{doi|10.1002/(SICI)1097-0126(199710)44:2}}
 </ref>
-:  {{chem|Cu|+}} <sup>−</sup>C(≡C−C≡)<sub>n</sub>C<sup>−</sup> {{chem|Cu|+}}
+:{{chem|Cu|+}} <sup>−</sup>C(≡C−C≡)<sub>n</sub>C<sup>−</sup> {{chem|Cu|+}}
 This interpretation has been disputed.<ref name=kroto> H. Kroto (2010), [http://www.rsc.org/chemistryworld/Issues/2010/November/CarbyneOtherMythsAboutCarbon.asp ''Carbyne and other myths about carbon'']. RSC Chemistry World, November 2010.
 </ref>
-Freshly prepared copper acetylide reacts with [[hydrochloric acid]] to form acetylene and copper(I) chloride.  Samples that have been aged with exposure to air or to copper(II) ions liberate also higher [[polyyne]]s H(−C≡C−)<sub>n</sub>H, with ''n'' from 2 to 6, when decomposed by [[hydrochloric acid]]. A "carbonaceous" residue of this decomposition also has the spectral signature of (−C≡C−)<sub>''n''</sub> chains.  It has been conjectured that oxidation causes polymerization of the [[acetylide]] anions {{chem|C|2|2-}} in the solid into [[linear acetylenic carbon|carbyne]]-type anions .C(≡C−C≡)<sub>n</sub>C<sup>2−</sup> or [[cumulene|polycumulene]]-type anions C(=C=C=)<sub>m</sub>C<sup>4−</sup>.<ref name=cataldo> Franco Cataldo (1999), ''From dicopper acetylide to carbyne''.Polymer International, volume 48, issue 1, pages 15-22. {{doi|10.1002/(SICI)1097-0126(199901)48:1}}
+Freshly prepared copper acetylide reacts with [[hydrochloric acid]] to form acetylene and copper(I) chloride. Samples that have been aged with exposure to air or to copper(II) ions liberate also higher [[polyyne]]s H(−C≡C−)<sub>n</sub>H, with ''n'' from 2 to 6, when decomposed by [[hydrochloric acid]]. A "carbonaceous" residue of this decomposition also has the spectral signature of (−C≡C−)<sub>''n''</sub> chains. It has been conjectured that oxidation causes polymerization of the [[acetylide]] anions {{chem|C|2|2-}} in the solid into [[linear acetylenic carbon|carbyne]]-type anions .C(≡C−C≡)<sub>n</sub>C<sup>2−</sup> or [[cumulene|polycumulene]]-type anions C(=C=C=)<sub>m</sub>C<sup>4−</sup>.<ref name=cataldo> Franco Cataldo (1999), ''From dicopper acetylide to carbyne''.Polymer International, volume 48, issue 1, pages 15-22. {{doi|10.1002/(SICI)1097-0126(199901)48:1}}
 </ref>
@@ Line 64: / Line 64: @@
 ==Applications==
-Though not practically useful as an explosive due to high sensitivity and reactivity towards water{{Citation needed|date=March 2011}}, it is interesting as a curiosity because it is one of the very few explosives that do not liberate any gaseous products upon detonation.
+Though not practically useful as an explosive due to high sensitivity, it is interesting as a curiosity because it is one of the very few explosives that do not liberate any gaseous products upon detonation.
 The formation of copper acetylide when a gas is passed through a solution of copper(I) chloride is used as a test for the presence of acetylene.
@@ Line 79: / Line 79: @@
 {{Copper compounds}}
+{{Carbides}}
 [[Category:Copper(I) compounds]]

v t e Copper compounds
Cu(0,I)	Cu₅Si
Cu(I)	CuBr CuCN CuCl CuF CuH CuI Cu₂C₂ Cu₂Cr₂O₅ Cu₂O CuOH CuNO₃ Cu₃P Cu₂S CuSCN C₆H₅Cu
Cu(I,II)	Cu₄O₃ Cu₃H₄O₈S₂
Cu(II)	Cu(BF₄)₂ CuBr₂ CuC₂ Cu(CH₃COO)₂ Cu(CF₃COO)₂ Cu(C₃H₅O₃)₂ CuCO₃ Cu₂CO₃(OH)₂ Cu(CN)₂ CuCl₂ / KCuCl₃ / K₂CuCl₄ Cu(ClO₃)₂ Cu(ClO₄)₂ CuF₂ Cu(NO₃)₂ Cu₃(PO₄)₂ Cu₃(BO₃)₂ Cu(N₃)₂ CuC₂O₄ CuO CuO₂ Cu(OH)₂ CuS Cu(SCN)₂ CuSO₄ Cu₃(AsO₄)₂ Cu(C ₁₁H ₂₃COO) ₂ Cu(C₁₇H₃₅COO)₂ CuTe CuTe₂
Cu(III)	K₃CuF₆
Cu(IV)	CuO₂ Cs₂CuF₆