Spectroscopic Examination of Alkali Halide HCN Complexes Assembled in Helium Droplets William K. Lewis and Roger E. Miller University of North Carolina at Chapel Hill Chapel Hill, NC 27599 Chromophore, Reactant, Adsorbate, etc Free rotation of embedded complex allows study via high-resolution infrared spectroscopy Binary HCN - Lithium Halide Complexes HCN-LiF LiF-HCN HCN LiX *contour spacing = 200 cm -1 HCN-LiCl LiCl-HCN HCN-LiF LiF-HCN HCN LiX *contour spacing = 200 cm -1 HCN-LiCl LiCl-HCN Binary HCN - Lithium Halide Complexes Cryostat Skimmer Multi-pass/Stark Cells +V -V Bolometer High Pressure Helium Nozzle HCN Pickup Cell Alkali Halide Crucible HCN-LiF Spectra ExpCalc* B (MHz) (Debye) *MP2/ G** HCN-LiCl Spectra ExpCalc* B (MHz) (Debye) How Reliable are the Calculated Dipoles? Alkali Halide Calculated Dipole (D) Literature Value (D) LiF LiCl NaF NaCl9.69.0 Including these effects lowers the predicted dipole to 10.3 Debye for LiF & 11.4 D for LiCl -sensitive to helium density Binary HCN - Sodium Halide Complexes HCN-NaClNaCl-HCN HCN ClNa HCN-NaF NaF-HCN HCN FNa HCN NaX HCN-NaF Spectra ExpCalc* B (MHz) (Debye) Debye HCN-NaCl Spectra ExpCalc* B (MHz) (Debye) Debye HCN-MX Frequency Shifts M=Li,Na X=F,Cl Conclusions Binary complexes of HCN and alkali halides form linear or square structures The properties of the system (binding energies, stretching frequencies) are sensitive to the size of the ion bound to the HCN chromophore Acknowledgements Jeremy Merritt Paul Stiles Gary Douberly Myong-Yong Choi Travis Falconer Mike Barrett Alessandra Ferzoco Andrew Draney NaCl NaF LiCl LiF 9.0 8.1 7.1 6.3