Ab Initio Calculations for Detectable New Isomers of Interstellar Carbon-Chain Radicals Cn(n=2–8)

[摘要] Detectablenewisomersofinterstellarcarbon-chain(linear)radicals,Cn(n=2–8),wereinvestigatedtheoreticallybasedonabinitioquantumchemicalcalculations.ThemolecularcharacteristicsofvariousCn(n=3–8)isomerswereexamined,anditwasfoundthat3-ringisomers(isomerswithathree-member-carbon-ring)ofC3H,C5H,andC7Hareatalowenergylevelrelativetolinearisomers,andthattheirdipolemomentsaresufficientlylarge.TheformationmechanismsofC3HandC5Hwerealsoexamined,anditwasfoundthatbothlinear-and3-ring-C3HandC5Hcanbeformedvianeutral-neutralreactions,C+C2H2→C3H+HandC+C4H2→C5H+H,respectively,ininterstellarspace.Thesefactsstronglysuggestthatcarbon-ring-chainradicals,C5HandC7H,areanewseriesofinterstellarmoleculesthatwillbedetectableinthelaboratoryandinterstellarspace.

[学科分类] 天文学(综合)

[关键词] "ISM: molecules";"molecular data";"molecular processes"