Tricarbon monoxide

Source: Wikipedia, the free encyclopedia.
"C3O" redirects here. For the C3O type of meteorite, see CM chondrite.
Tricarbon monoxide
Names
Preferred IUPAC name
3-Oxopropa-1,2-dien-1-ylidene
Other names
3-Oxopropadienylidene
Identifiers
3D model (
JSmol
)
  • InChI=1S/C3O/c1-2-3-4
    Key: ZCNKODXATWVMAO-UHFFFAOYSA-N
  • [C-]#CC#[O+]
Properties
C3O
Molar mass 52.032 g·mol−1
Appearance Gas
Related compounds
Related oxides
 carbon monoxide
dicarbon monoxide
tetracarbon monoxide
Related compounds
carbon subnitride
HCCCO[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Tricarbon monoxide C3O is a reactive

inert gas matrix or made as a short lived gas. C3O can be classified as a ketene or an oxocumulene a kind of heterocumulene.[3]

Natural occurrence

C3O has been detected by its microwave spectrum in the dark cold

Taurus Molecular Cloud One[4] and also in the protostar Elias 18.[5]

The route to produce this is speculated to be:[6]

HC+
3 + CO2 → HC3O+ + CO
HC3O+ → C3O + H+

or[5]

C2 + CO → C3O which is more favourable at lower temperatures.

The related C3S is more abundant in dark molecular clouds, even though oxygen is 20 times more common than sulfur. The difference is due to the higher rate of formation and that C3S is less polar.[5]

Production

C3O can be produced by heating Meldrum's acid. This also produces acetone, carbon monoxide and carbon dioxide.[7]

R. L. DeKock and W. Waltner were the first to identify C3O by reacting atomic carbon with carbon monoxide in an argon matrix. They observed an infrared absorption line at 2241 cm−1.[7] They produced carbon atoms by heating graphite inside a thin tantalum tube.[8]

M. E. Jacox photolysed C3O2 in an argon matrix to produce C3O with an IR absorption line at 2244 cm−1, however he did not recognise what was produced.[8]

By heating diazocyclopentanetrione or a similar acid anhydride, (2,4-azo-3-oxo-dipentanoic anhydride), C3O is produced. Also the action of light on tetracarbon dioxide yields C3O and CO.[9]

Heating fumaryl chloride also yields C3O.[3] Heating Lead 2,4-dinitroresorcinate also produces C3O along with C2O, CO and carbon suboxide.[10] An electric discharge in carbon suboxide produces about 11 ppm C3O.[11]

Roger Brown heated 3,5-dimethyl-1-propynolpyrazole to over 700 °C to make C3O.[12] Also pyrolysis of 5,5'-bis(2,2-dimethyl-4,6-dioxo-1,3-dioxanylidene or di-isopropylidene ethylenetetracarboxylate yields C3O.[12]

Irradiating carbon monoxide ice with electrons yields a mixture of carbon oxides, including C3O. This process could happen on icy bodies in space.[13]

Reactions

C3O can be stabilised as a ligand in the pentacarbonyls of group 6 elements as in Cr(CO)5CCCO. This is formed from [n-Bu4N][CrI(CO)5] and the silver acetylide derivative of sodium propiolate (AgC≡CCOONa), and then

acetylenes and cumulenes in the solvent. Dimethyl sulfoxide oxidises the CCCO ligand to carbon suboxide./[15]

C3O deposits a reddish-black film on glass.[12]

The reaction of C3O and

isocyanuric acid and propiolamide, the NH then reacts to bond with the triple bond, with the NH2 group moving back. Then a final cyclisation occurs to make uracil.[17]

Properties

The C3O molecules do not last long. At the low pressure of 1 pascal, they survive about one second.[18] The force constants for the bonds are: C1-O 14.94, C1-C2 1.39 C2-C3 6.02 mdyn/Å.[8] The bond lengths are C-O 1.149, C1-C2 1.300, C2-C3 1.273 Å. The molecule is linear.[6]

bond atom 1 atom 2 length
Å[6] 		force constant
mdyn/Å[8] 		IR bands
cm−1
CCC-O C1 O 1.149 14.94
CC-CO C2 C1 1.300 1.39
C-CCCO C3 C2 1.273 6.02

Proton affinity is 885 kJmol−1.[6] The dipole moment is 2.391 D.[14] The oxygen end has a positive charge, and the carbon end the negative charge.[6] The molecule behaves as if there are triple bonds at each end, and a single bond in the middle. This is isoelectronic to cyanogen.[19]

Molecular constants used in determining the microwave spectrum are rotational constant B0=4810.8862 MHz centrifugal distortion constant D0=0.00077 MHz. Known microwave spectral lines vary from 9621.76 for J=1←0 to 182792.35 MHz for J=19←18.[11]

References

  1. doi:10.1021/ja00334a002
    .
  2. doi:10.1086/186284
    .
  3. ^ a b Ruppel, Raimund (1999). "Neue Heterokumulene und Carbene" (PDF) (in German). Gießen: Justus-Liebig-Universität: 13. Retrieved 10 November 2016. {{cite journal}}: Cite journal requires |journal= (help)
  4. S2CID 4335136
    .
  5. ^
    S2CID 124813337
    .
  6. ^
    doi:10.1063/1.455787
    .
  7. ^
    doi:10.1021/ja00359a026. image of the tricarbon monoxide research team
  8. ^
    doi:10.1021/ja00754a081
    .
  9. doi:10.1002/anie.199009051
    .
  10. doi:10.1016/0040-6031(85)87024-6
    .
  11. ^
    doi:10.1016/0009-2614(85)80130-5
    .
  12. ^
    doi:10.1016/S0040-4039(01)84602-5
    .
  13. doi:10.1086/499245
    .
  14. ^
    ISBN 978-3642047213
    .
  15. doi:10.1002/anie.198002251
    .
  16. PMID 21400561
    .
  17. PMID 22120518
    .
  18. ^ Information, Reed Business (9 May 1985). "Theory predicts a new oxide of carbon". New Scientist (1455): 21. Retrieved 10 November 2016. {{cite journal}}: |first1= has generic name (help)
  19. doi:10.1021/ja00312a013
    .
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