1. 61 st Symposium on Molecular Spectroscopy June 19, 2006  -doubling in High Angular Momentum States: High Resolution Spectroscopy of CoF (X 3  i ) M. A. Flory, P. M. Sheridan, M. A. Brewster, S. K. McLamarrah, L. M. Ziurys Department of Chemistry, Department of Astronomy, Steward Observatory University of Arizona T. C. Steimle Department of Chemistry and Biochemistry Arizona State University and J. M. Brown Physical and Theoretical Chemistry Laboratory University of Oxford

2. 61 st Symposium on Molecular Spectroscopy June 19, 2006 CoF Motivation Working on transition metal fluoride series – RE08 (ZnF) Interested in Co bonding – Recent studies of CoCl, CoCN, CoS, CoO CoCl highly perturbed While CoF previously studied, a complete, high- resolution spectrum is desired – You never know what you’re going to get!

3. 61 st Symposium on Molecular Spectroscopy June 19, 2006 Past Studies of CoF Several electronic and rotational studies –T. Okabayashi & M. Tanimoto, J. Mol.Spec., 221, 2003 –X. Zheng, J. Guo, T. Wang, L. Pei, Y. Chen, C. Chen, J. Mol.Spec., 220, 2003. –A. G. Adam & W. D. Hamilton, J. Mol.Spec., 206, 2001. –R. S. Ram, P. F. Bernath, & S. P. Davis, J. Chem. Phys., 104, 1996. –R. S. Ram, P. F. Bernath, & S. P. Davis, J. Mol.Spec., 173, 1995. –A. G. Adam, L. P. Fraser, W. D. Hamilton, & M. C. Steeves, Chem. Phys. Lett., 230, 1994. No pure rotational spectrum of all 3 spin components –Hund’s Case (a) fit with 2 nuclear spins Co nuclear spin (I = 7/2) F nuclear spin (I = 1/2) –  -doubling in  = 3 and 2

4. 61 st Symposium on Molecular Spectroscopy June 19, 2006 Radiation Source: Phase- locked Gunn oscillators and Schottky diode multipliers (65- 660 GHz) Gaussian beam optics utilized to minimize radiation loss Reaction Chamber: Double walled, steel cell which contains a Broida-type oven Detector: InSb bolometer Radiation is modulated at 25kHz and detected at 2f Direct Absorption Submillimeter Spectroscopy

5. 61 st Symposium on Molecular Spectroscopy June 19, 2006

6. Co vapor produced in high temp Broida-type oven –m.p. = 1495 °C –Zircar insulating felt/alumina sleeve –Molybdenum posts Reacted with 10% F 2 in He (25 mTorr mixture) No d.c. discharge required No additional carrier gas used Initial search based on B values by Ram et al. (1996) Gas-Phase Synthesis of CoF

7. 61 st Symposium on Molecular Spectroscopy June 19, 2006  = 4  = 3  = 2 Energy 3A SO 6A SO J=5 J=4 3 Fine structure components  J ≥  Hyperfine levels J + I (Co) = F 1 F 1 + I (F) = F J=5 J=4 J=3 J=5 J=4 J=3 J=2 F1F1 F 3  i Energy Levels

8. 61 st Symposium on Molecular Spectroscopy June 19, 2006 CoF Spectra 680 individual lines measured from 14 rotational transitions in range 255-651 GHz

9. 61 st Symposium on Molecular Spectroscopy June 19, 2006  -doubling Theory for  states Not worked out for  states – Only seen in CoH (X 3  i )  = 3 Connect              electronic states (6 th order effect) Case (a) Hamiltonian of the form (with J. Brown): H  D = /2(J + 6 + J - 6 ) – /2(J + 5 S + + J – 5 S – ) + /2(J + 4 S + 2 + J – 4 S – 2 ) – ñ  /2(J + 3 S + 3 + J – 3 S – 3 ) + /2(J + 2 S + 4 + J – 2 S – 4 ) – /2(J + S + 5 + J – S – 5 ) + /2(S + 6 + S – 6 ) where = q  = p  + 6q  = o  + 5p  + 15q , etc. and H  D = Convert using Van Vleck transformation/Wigner-Eckart Theorem

10. 61 st Symposium on Molecular Spectroscopy June 19, 2006  -doubling for 3  states e.g.   6; S  ± 2; J,   4  H LD  ; S  ; J,   = -( /2)[ {J(J + 1) – (   4) (   3)}{J(J + 1) – (   3) (   2)}{J(J + 1) – (   2) (   1)}  {J(J + 1) – (   1)  }{S(S + 1) – (  ± 1)  }{S(S + 1) – (  ± 1) (  ± 2)}] 1/2 For 3  state, first 3 terms give a 3 x 3 matrix  = 2 diagonal term: 3  matrix X = J(J+1) | 3  4 > | 3  3 > | 3  2 > < 3  4 |- - /2 * X(X-2)(X-6) 1/2 (X-12) 1/2 < 3  3 |sym. /2*X(X-2)(X-6) - /√2*X(X-2)(X-6) 1/2 < 3  2 |sym. sym. *X(X-2) Simplifies to Hamiltonian matrix:

11. 61 st Symposium on Molecular Spectroscopy June 19, 2006 This work (  = 3 & 4)Okabayashi (  = 4) Adam (2001) B 11638.2112(24)11635.32099(51)11643.9(7.8) D 0.0154741(18)0.0153437(10)0.0151395 a H -6.038*10 -9 a A -6981350 a -6981350(160) ADAD 3.1779(23)0 a AHAH 0.0000345(41) -20890 a -20890(240) 4.128(98)*10 -08 a(Co) 563.09(58)h(Co) = 974.9(18) a D (Co) 0.0192(21) b F (Co) -716.4(3.3) b b FD (Co) -0.026(11) eqQ -73(12)-77.50(91) a(F) 94.7(3.5)h(F)= 233.52(32) a D (F) 0.076(12) b F (F) -34(22) b b FD (F) -0.165(46) rms 0.252 In MHz. a) Fixed b) hyperfine c set to 0 Hund’s case (a) Hamiltonian H eff = H Rot + H SO + H SS + H  -d + H hf(Co) + H hf(F) In addition to  -doubling terms, 2 nuclears spins not trivial (T.C. Steimle) Preliminary results (  = 3 & 4) in good agreement with previous studies Hoping to finish by the end of the week! Analysis

12. 61 st Symposium on Molecular Spectroscopy June 19, 2006  Lucy Ziurys  Prof. J. M. Brown  Prof. T. C. Steimle  Prof. P. M. Sheridan  Ziurys Group  Dr. Aldo Apponi  Dr. DeWayne Halfen  Shawn McLamarrah, Stefanie Milam, and Emmy Tenenbaum  Funding – NSF, NASA Laboratory Astronomy Thanks to…