Saturday, January 17, 2009

Circumnames

I came across these “circumnames” quite by chance: several compounds were mentioned in this paper and some other can be found in this astrochemistry database. Is there any elegant way to name them systematically?

circumpyrene
(a) circumpyrene
ovalene
(b) ovalene
pyrene
(c) pyrene

For instance, ACD/Name gives the molecule (a) a systematic name dinaphtho[2,1,8,7-hijk:2',1',8',7'-stuv]ovalene, i.e. two naphtho groups are fused to the top and bottom of the ovalene (b) molecule, while the non-systematic name “circumpyrene” means that pyrene (c) core is completely encircled by fused benzene rings. Unfortunately, I was unable to generate ACD/Names for bigger molecules, such as circumcoronene (d) [i.e. coronene (e) encircled by fused benzene rings] and circumovalene (f). Apparently, ACD/Name cannot name compounds with more than 15 fused rings.

circumcoronene
(d) circumcoronene
coronene
(e) coronene
circumovalene
(f) circumovalene

If the “core” structure is surrounded by two rows of fused benzene rings, the doubly “circum” names like circumcircumpyrene (g) and circumcircumcoronene (h) appear.

circumcircumpyrene
(g) circumcircumpyrene
circumcircumcoronene
(h) circumcircumcoronene

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