Three isotopic species of a weakly bound Thyphen;shaped pgr; complex formed between acetylene and HCl have been observed through the assignment of their rotational spectra by the use of a pulsed, Fourierhyphen;transform spectrometer with a high pressure gas being pulsed into an evacuated Fabryndash;Perot cavity. The spectra clearly show the complex to be a nearly prolate asymmetric top (kgr; = minus;0.9898) with the HCl on theahyphen;inertial axis and perpendicular to acetylene and with the hydrogen atom pointing towards the middle of the acetylene triple bond. The chlorine is situated, on average, 3.699 Aring; from the edge of the acetylene molecule. The following molecular constants have been obtained for the C2H2, H35Cl isotopic species: The rotational constants areA= 36thinsp;084(838),B= 2481.065(6), andC= 2308.602(6) MHz; the nuclear quadrupole coupling constants are khgr;aa= minus;54.342(4), khgr;bb= 26.862(5), and khgr;cc= 27.480(9) MHz, and the rotational centrifugal distortion constants areDJ= 7.9(4) andDJK= 497(8) kHz.
展开▼
