首页>
外文期刊>journal of chemical physics
>Infrared spectroscopy of carbohyphen;ions. VI. Cndash;H stretching vibration of the acetylene ion C2H2+and isotopic species
【24h】
Infrared spectroscopy of carbohyphen;ions. VI. Cndash;H stretching vibration of the acetylene ion C2H2+and isotopic species
展开▼
机译：Infrared spectroscopy of carbohyphen;ions. VI. Cndash;H stretching vibration of the acetylene ion C2H2+and isotopic species
The infrared spectra of the band of the2Pgr;ndash;2Pgr; asymmetric hydrogen stretching vibration in the three isotopic acetylene ions C2H2+(ngr;3),13C2H2+(ngr;3), and DCCH+(ngr;1) have been observed and analyzed. The high resolution infrared spectra were recorded using a differencehyphen;frequency laser spectrometer as the tunable coherent infrared source probing an ac glow discharge. Velocity modulation, noise subtraction, and unidirectional multipassing of the infrared beam through the discharge cell provided high sensitivity. C2H2+was produced in a gas mixture of H2, He, and either CH4or C2H2, with a total pressure of ape;7 Torr in multiplehyphen;inletndash;outlet airhyphen;, waterhyphen;, and liquidhyphen;nitrogenhyphen;cooled discharge tubes; C2H2freezing precluded its use in liquidhyphen;N2hyphen;cooled discharges. Complicated by a strong perturbation whose maximum occurred atNrsquo;=15 forF1andNrsquo;=14 forF2, the assignment of the spectrum of normal C2H2+was made possible by (1) fortuitous discharge conditions which provided unambiguous discrimination of C2H2+lines from among concurrent CH3+and C2H3+lines, and (2) fitting the ground state combination differences. Sufficiently highNtransitions were observed where Lgr; doubling was evident. The average bond lengthsrz(CH)=1.077 (5) Aring; andrz(CC)=1.257 (8) Aring; were calculated from the spectroscopic constants determined from nonlinear leasthyphen;squares fitting. Vibrationndash;rotation interactions, the Rennerndash;Teller interaction of perturbing states, plasma chemistry, and the relevance of the work in astrophysics are discussed.
展开▼
