Magnetic g e -factors and electric dipole moments of Lanthanide monoxides: PrO * Hailing Wang, and Timothy C. Steimle Department of Chemistry and Biochemistry Arizona State University Colan Linton Center for Laser Atomic and Molecular Sciences (CLAMS) Physics Department, University of New Brunswick, Fredericton, NB, Canada E3B 5A3 * Fund by DoE-BES 64 th OSU International Symposium on Molecular Spectroscopy June 25, 2009 Motivation to study LnO Gain insight into the Actinides from the Lanthanides Test of LFT (ligand field theory) Establish bonding trends Helmholtz Coils Supersonic Molecular beam optical spectrometer Stark plates Electrical Leads 0.64 Molecular Beam Probe Laser Beam Stark Plates LIF F " PrO Field-Free Spectra X 1 (=3.5) X 2 (=4.5) [16.6]= T 0 (cm -1 ) [18.1]= FWHM < 50 MHz z: selected for Zeeman measurement s: selected for Stark measurement This study Too overlapped 141 Pr (I=5/2) PrO Stark Asymmetric Stark Shift: 2nd order effects important Stark Spectrum R(4.5) F=3-F=2 Stark Energy Levels Symmetric Zeeman Shift: Approximately no 2nd order effects Zeeman Spectrum P (6.5) F=5-F=6 PrO Zeeman Zeeman Energy Levels Analysis Stark shifts F=2 22 F=3 22 F=7 22 F=3 22 F=4 22 F=8 22 el = 3.01(3)D el = 4.72(4)D X 2 ( =4.5) 1212 Mat Rep [18.1] ( =5.5) 1212 Mat Rep Analysis (Cont.) Zeeman shifts Determined Magnetic g e factors g e (X 2 ( =4.5)) = (82) g e ([18.1] =5.5) = (55) Modeling the Linear Zeeman tuning: Ang. Mom. operator Least sq. fitting Discussion- Dipole moments LnO Dipole Moments DFT Calculation Wu et al, J. Cluster Sci. 13, 444 (07) CeO YbOHoONdOPrO X 2X 2 1 X 1 + X X4 X ( =4.5) 2 State (Debye)3.12(1)5.89(2)4.80(5)3.37(1)3.01(3) Note: smooth increase with At. # Interpretation of trends in ground state el =3.01D PrO =4.80D HoO Note: contraction Following Fields group (Schall et al JCP 85 (1986)) el as an Pr +2 function Pr +2 Discussion- g e -factors el (Pr +2 ) =|J c,J a,M Ja The O -2 ligand mixes the Pr +2 states: el (Pr +2 O -2 ) = c i [|J c,J a, ] JaJa Valence 6s j(=s) Core f 2 electrons Coupled JcJc Energy levels of Pr +2 f2f2 3 H 4,5,6 JcJc ScSc LcLc JaJa JcJc Energy g e = 4.25 LFT Predict g e = 4.49 Experiment Discussion- g e -factors = Schall et al (JCP 85,1986) Eq. 1 Eq. 2 and Eq. 2 Eq. 1 Ligand Field prediction for el (PrO) el (X 2 ( = 4.5)) = 0.98|4, 4.5 |5, 5.5 |5, 4.5 Carette, P. et al., J. Mol. Spectrosc. 1988, 131, 301. C1C1 C3C3 C2C2 Conclusion The published DFT predictions for the el are in poor agreement with our experimental results LFT works well for predicting how the angular momentum of the electrons sum up to produce the m of the lanthanide monoxides. Thank you for your attention! QUESTIONS?