Carbon dichalcogenide

Carbon dichalcogenides are chemical compounds of carbon and chalcogen elements. They have the general chemical formula CZ2, where Z = O, S, Se, Te.

This includes:


 * Carbon dioxide, CO2
 * Carbon disulfide, CS2
 * Carbon diselenide, CSe2
 * Carbonyl sulfide, OCS
 * Carbonyl selenide, OCSe
 * Thiocarbonyl selenide, SCSe
 * Thiocarbonyl telluride, SCTe

Stability
Double bonds between carbon and chalcogen elements, C=Z, become weaker the heavier the chalcogen, Z. This trend means carbon dichalcogenide monomers are less stable and more susceptible to polymerisation as Z changes from O to Te. For example, CO2 is stable, CS2 polymerises under extreme conditions, CSe2 tends to polymerise, CSeTe is unstable and CTe2 does not exist. This trend is an example of the double bond rule.

Bonding
In carbon dichalcogenides, C=O bond lengths are around 1.16 Å, C=S around 1.56 Å, C=Se around 1.70 Å and C=Te around 1.90 Å.