Cyclo(6)carbon
Template:Short description Template:Correct title <templatestyles src="Chembox/styles.css"/>
Template:Chembox image cellTemplate:Chembox AllOtherNamesTemplate:Chembox headerbarTemplate:Chembox IndexlistTemplate:Chembox JmolTemplate:Chembox ChEMBLTemplate:Chembox ECHATemplate:Chembox E numberTemplate:Chembox IUPHAR ligandTemplate:Chembox UNIITemplate:Chembox CompToxTemplate:Chembox headerbarTemplate:Chembox Datapage checkTemplate:Chembox Footer| Template:Longitem | Template:Unbulleted list |
| ChEBI | Template:Unbulleted list |
| ChemSpider | Template:Unbulleted list |
| DrugBank | Template:Unbulleted list |
| EC Number | Template:Unbulleted list |
| KEGG | Template:Unbulleted list |
| Template:Longitem | Template:Unbulleted list |
| RTECS number | Template:Unbulleted list |
| Script error: No such module "collapsible list". | |
| Script error: No such module "collapsible list". | |
| Template:Longitem | Template:Chembox Elements/molecular formula |
| Molar mass | Template:Chem molar mass |
Template:Chembox Footer/trackingScript error: No such module "TemplatePar".Template:Short description
Cyclo[6]carbon is an allotrope of carbon with molecular formula Template:Chem2. This theoretical molecule is a ring of six carbon atoms, connected by alternating double bonds.[1] It is, therefore, a member of the cyclo[n]carbon family.
There have been a few attempts to synthesize cyclo[6]carbon, e.g. by pyrolysis of mellitic anhydride,[2] but without success until 2023, when it was successfully synthesised by atom manipulation of hexachlorobenzene, although more thorough research has yet to be reported in peer reviewed scientific work.[1] Another synthesis was reported in 2025 by the dehalogenation of hexaiodobenzene on a sodium chloride layer on an Au(111) surface.[3] The molecule's structure presents double bonds in sequence in a bent fashion, which is not explained by valence bond theory for organic molecules, that describes double bonds by combinations of hybridised sp2 orbitals, limiting the molecule's geometry in terms of increase of energy due to bond angles. Cyclo[6]carbon would present then low probability of formation due to its high energy state from a thermodynamical perspective, which is reflected on the lack of evidence of its successful synthesis.
Calculations suggest that the alternative cyclic cumulene structure, called cyclohexahexaene, is the potential energy minimum of the cyclo[6]carbon framework.[4]
References
<templatestyles src="Reflist/styles.css" />
Script error: No such module "Check for unknown parameters".
Script error: No such module "Navbox".