# $K \neq 0$ TRANSITIONS IN THE ROTATIONAL SPECTRUM OF Ar-HCN

Please use this identifier to cite or link to this item: http://hdl.handle.net/1811/12330

Files Size Format View
1991-FA-03.jpg 102.0Kb JPEG image

 Title: $K \neq 0$ TRANSITIONS IN THE ROTATIONAL SPECTRUM OF Ar-HCN Creators: Germann, T. C.; Emilsson, T.; Gutowsky, H. S. Issue Date: 1991 Publisher: Ohio State University Abstract: The Ar-HCN dimer has been $described^{1}$ as a highly nonrigid molecule, with several spectroscopic anomalies attributed to strong angular--radial coupling in the interaction $potential.^{1-4}$ In earlier work only $K=0$ transitions were observed and the dimer has been viewed as pseudolinear. However, a previously calculated potential $surface^{2}$ exhibits a local maximum for the linear structure and a minimum for structures bent by $\sim 15^{0}$, with smaller angles favored at larger Ar to HCN separations. We now report the observation of four very weak $K\neq 0$ transitions which suggest that the Ar-HCN ground state structure is indeed bent, with (B-C) -- 16 MHz. The line centers are given below, in MHz. Those for $K = 0$ are from earlier $work.^{1,2}$ [FIGURE] Analysis of the hyperfine structure of the $K\neq0$ transitions, produced by quadrupole interactions of the $14_{N}$, gives coupling constants which are quite different from those determined for the $K=0$ transitions. Further analysis is in progress and will be $discussed.^{1}$ K. R. Leopold, G. T. Fraser, F. J. Lin, D. D. Nelson, JR., and W. Klemperer, J. Chem. Phys. 81, 4922 (1984). $^{2}T$. D. Klots, C. E. Dykstra, and H. S. Gutowsky, J. Chem. Phys. 90, 30 (1989). $^{3}G$. T. Fraser and A. S. Pine, J. Chem. Phys. 91, 3319 (1989), R. E. Burngarner and G. A. Blake, Chem. Phys. Lett. 161, 308 (1989). $^{4}D$. C. Clary, C. E. Dateo, and T. Stoecklin, J. Chem. Phys. 93, 7666 (1990). Description: Author Institution: Noyes Chemical Laboratory, University of Illinois URI: http://hdl.handle.net/1811/12330 Other Identifiers: 1991-FA-3