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, Carbon disulfide, Carbon diselenide, 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, is stable, polymerises under extreme conditions, tends to polymerise, CSeTe is unstable and 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.
+Carbon–chalcogen double bond lengths in carbon dichalcogenides, Z=C=Z′ Species Formula Z Z′ Bond Bond in molecule Bond length / Å Method of determination Reference Carbon dioxide CO2 O O C=O O=C=O 1.163 infrared spectroscopy Carbon disulfide S S C=S S=C=S 1.553 infrared spectroscopy Carbon diselenide Se Se C=Se Se=C=Se 1.689 neutron diffraction Carbonyl sulfide OCS O S C=O S=C=O 1.158 microwave spectroscopy C=S O=C=S 1.560 microwave spectroscopy Carbonyl selenide OCSe O Se C=O Se=C=O 1.159 microwave spectroscopy C=Se O=C=Se 1.709 microwave spectroscopy Thiocarbonyl selenide SCSe S Se C=S Se=C=S 1.553 microwave spectroscopy C=Se S=C=Se 1.693 microwave spectroscopy Thiocarbonyl telluride SCTe S Te C=S Te=C=S 1.557 microwave spectroscopy C=Te S=C=Te 1.904 microwave spectroscopy
References