UV/Vis Absorption Experiments on Mass Selected Cations by Counter- Ion Introduction in an Inert Neon Matrix Nathan Roehr University of Florida 67 th International Symposium on Molecular Spectroscopy

Thanks  Dr. Nick Polfer  Dr. Martin Vala  Dr. Jan Szczepanski  Dr. John Eyler  Polfer and Eyler Group  Ardara Technologies – Randy Pedder  Machine and Electronic Shop  Physical Chemistry Travel Grant  ACSPRF #49572-­‐DNI6  67 th Ohio State Symposium of Molecular Spectroscopy  Dr. David Moore  Ryan Ludwig  Alex Hunter  Moore Group Members Lehigh UniversityUniversity of Florida

Outline  Matrix Isolation of Mass-Selected Ions  Counter-Ion Introduction  UF Instrument CO + and SF 6 - Results  Lehigh instrument Cu - and Ar + /Kr + Results  Summary

Inert Gas Inlet Cold (4-20K) Cryostat Target 90 or 270 deg Ion Bender Quadrupole Mass Filter Einzel C Einzel B 4 Inlet for Neutral Electron Filament (EI Source) (+) (-) Einzel A (-) hrs  Source of Ionization  Mass Analyzer or Mass Filter  Electrostatic/Electrodynamic Ion Guides  Cold Cryostat Target nA of Ion Current Experimental Set-Up for Matrix Isolation Expts on Mass-Selected Cations

Other Modifications 5 hh hh CS 2 + Cl -  Originally Neglected  Cold Metal Bombardment  Electron gun Inert Gas Inlet Cryostat Target  Only Works for Cations  Use of Scavenger And Scavenger  Atomic or Molecular Counter Ions  It didn’t work Leroi, G. et al,Soc. for Applied Spec. 15, 4 (1991). Counter Ions zxzx  Inconsistent  Unknown Counter-Ions  Throwing Away Ions

CI Source EI Source Cryostat Window Deflector Quadrupole Mass Filter FT IR UF Instrument CO SF 6 ~5 nA of both CO + and SF 6 - ions 10 V bias 12 hrs of Deposition

IR Spectra - CO + and SF 6 - Deposition Absorbance Wavenumber / cm cm -1 ν m CO cm -1 ν a CO CO + Gas cm -1 Solid Neon – cm -1 ? Jacox, M.E., Chem. Phys. 189, (1994)

David Moore Assistant Professor Alex Hunter Masters Student Ryan Ludwig Grad Student Lehigh University

UV-Vis CCD Detector UV-Vis Source Quadrupole Ion Guide Quadrupole Mass Filter Octopole Ion Guide EI Source KBr Window Deflector Magnetron Aggregation Region Lehigh Instrument ~3-5 nA of both Cu - and Ar + or Kr + ions 10 V bias 3 hrs of Deposition Cu Target Ar or Kr 20K or 15K Ar

λ / nm UV Spectra Cu - and Ar + Deposition Absorbance Ozin, G.A. et al, J. Phys. Chem. 86, (1982) Literature Cu Neutral: (4p) 2 P <- (4s) 2 S 299, 302, 306 Thermally Unstable - 319, /25 20K 05/28 λ / nm

Absorbance 10K 20K 32K 10K 20K 32K λ / nm UV Spectra Comparison 05/2805/25

Absorbance 20K 26K 32K 50K 100K 300K λ / nm UV Spectra Cu - and Ar + Deposition Akilbekov, A.T. et al, Fiz. Tverd, Tela, 86, (1982).

Absorbance 0.14” Lower Center 0.14” Higher λ / nm UV Spectra Cu - and Kr + Deposition 15K

 Detectable Quantities of Neutral Species Trapped in Solid Argon  Deposition Occurred Mostly at the Beam Center  Temperature Affected Ratio of Thermally Unstable Bands Summary & Conclusions

 Deposit Neutral Cu to Check Peak Ratio at ~ nm  Deposit Cu 2 - into Matrix  Introduce O 2 or CO with Matrix Gas to See if Metal Ligand Complexes Form  Deposit Cu + to Determine Cation/Neutral Ratio Further Work

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UF Setup