Carbon suboxide electronic structures

Carbon suboxide is a linear symmetric molecule in its ground state and is of considerable Interest from a variety of viewpoints. Its electronic structure, for example, has been subjected to considerable theoretical analysis because of the extensive delocalized IT network. Because its constituent atoms are doubly bonded C and 0, it is the source of intensely chemiluminescent flames with atomic oxygen which have been shown to result in inverted distributions in product CO. The molecule has also been proposed as (i) a product of photochemical reactions in the primitive earth atmosphere, (il) a constituent of the Venus atmosphere, and (iii) a possible explanation for the variety of colors associated with the Mars surface. 

The electron-diffraction investigation of the structure of molecules of methyl azide and carbon suboxide. Proc. Natl. Acad. Sci. 19 (1933) 860-867. (L. O. Brockway and Linus Pauhng). 

It also forms a third (very uncommon) oxide, carbon suboxide, C3O2, which is linear. The structure has terminal oxygen atoms on both ends. Write the Lewis formula for CjOj. How many electron groups are there about each of the three carbon atoms ... 

It is actually fairly unusual for a bound-to-bound Franck-Condon spectrum to be nearly devoid of structure, as is carbon suboxide. There is only so much "damage" the promotion of a single electron can do, and it is uncommon to see large displacements of several modes. The more structure there is in a spectrum, the more one can potentially extract about the regional potential surface. Even carbon suboxide has some structure spaced at about 620 cm , so we can be sure that (t) makes at least one pass near after... 

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