1. HYPERFINE SPLITTING AND ROTATIONAL ANALYSIS OF THE DIATOMIC MOLECULE ZINC MONOSULFIDE, ZnS DANIEL J. FROHMAN, G. S. GRUBBS II AND STEWART E. NOVICK O.S.U. 2011 TC11

2. 22 Motivation & Goals Laser ablation allows FTMW study of refractory materials in the gas phase that were previously inaccessible to us: low vapor pressure materials, metals Halogens, nitrides, and sulfides of transition metals such as Cu and Zn in a vdW complex with H 2 represent basic units within a metal organic framework (MOF) (NSF CHE – 1011214) MOF’s are a promising way to store and transport H 2 safely and relatively inexpensively through physisorption ZnS microwave data necessary to prepare for our future projects involving diatomic zinc molecules complexed with hydrogen such as ZnS-H 2 and ZnO-H 2.

3. 33 1064 nm Nd:YAG Laser 4-5 ns pulse width, up to 20 Hz repetition 1 max power ~ 45 mJ/pulse 1 Interfaced with spectrometer’s controlling program, FTMW++ 2 flashlamp is externally triggered by a N.I. CA-1000 pulse delay generator to give one laser pulse per nozzle pulse 1.) 90-1042A Polaris ST Operator’s Manual, New Wave Research, Inc., 2002 2.) Grabow, J.-U.; Ohio State University International Conference on Molecular Spectroscopy. Columbus, 2001.

4. 44 Ablation Nozzle Mounted on stationary mirror & modeled on Walker-Gerry design 1 0.5 mm diameter General Valve Series 9 with ablation adapter head Off-center 5.5 mm diameter bored out hole in adapter head 5 mm from nozzle exit contains ~ 5 mm ablation rod Adapter head gas channel is 4.8 mm diameter and 22.6 mm in length Laser enters through channel perpendicular to ablation rod and gas flow channels Oriel motor mike and controller gives continuous vertical movement and rotation of rod with IR triggers setting the travel distance Walker, K. ; Gerry, M. J. Mol. Spec., 182 1997 178.

5. 55 Ablated Zinc

6. 66 Ablated Zn Clip

7. 77 ZnS Pure rotational spectrum of ZnS ( 1 Σ + ) with the first vibrational satellites (v=1) observed in mm- wave 1 which gives centrifugal distortion constants and rotational constants to predict spectra Microwave region studies can refine rotational constants with additional vibrational satellites (v = 1 to 5) and lower J transitions and observe 67 Zn 32 S electric quadrupole splitting To our knowledge, no closed shell zinc diatomic species electric quadrupole hyperfine structure has been reported ZnS helps prepare for our future Zn containing vdW complex projects as well as a test of our ability to see transition metal species Photo from http://www.webelements.com/zinc/http://www.webelements.com/zinc/ 1.) Zack, L.; Ziurys, L.; J. Mol. Spec. 257 2009 213

8. 88 ZnS Production

9. 99 Dunham Band Parameters Watson, J.; J. Mol. Spec. 80 1980 411 Dunham band parameters, Y kl, are an approximation of isotopically mass dependent rotational and vibrational constants for diatomic molecules Y 01 ~B e, Y 11 ~-α e, Y 21 ~γ e, Y 31 ~ δ e, Y 41 ~ ε e, Y 12 ~ -β e, Y 02 ~ -D e, are used in a power series to describe vibration-rotation energies Under high resolution spectroscopy, Born-Oppenheimer approximation within Y kl may not hold Significant deviation from the B.O. approximation may require modification of the band parameters to include B.O. breakdown (BOB) terms, Δ kl BOB terms have an inversely proportional relation to atomic mass and thus may be be larger with lighter atoms

10. 10 Dunham Analysis 1.) Zack, L.; Ziurys, L.; J. Mol. Spec. 257 2009 213 2.) Pickett, H.M., J. Molec. Spect. 148 1991 371 All vibrational states of all isotopomers fit to one set of constants (Dunham band parameters) with reduced mass ratio scaling Δ 01 (Zn) was fit 2 but found to be zero within experimental accuracy No Born-Oppenheimer breakdown was observed detected in the ground electronic state of ZnS up to v = 5 U 01 120675.415 (36) MHz amu U 11 -3184.77 (40) MHz amu 3/2 U 21 -48.4 (13) MHz amu 2 U 31 29.5 (15) MHz amu 5/2 U 41 -29.92 (56) MHz amu 3

11. 11 Spectroscopic constants for ZnS a (in MHz) a.With the values of D e and β e held to the values given in Ref 1 for 64 Zn 32 S, 3.8372 kHz and - 0.02 kHz respectively, and scaled appropriately for the other isotopomers. 1.) Zack, L.; Ziurys, L.; J. Mol. Spec. 257 2009 213 2.) Pickett, H.M., J. Molec. Spect. 148 1991 371 64 Zn 32 S (45.8%) 64 Zn 32 S Ref 1 66 Zn 32 S (26.6%) 66 Zn 32 S Ref 1 68 Zn 32 S (18.1%) 68 Zn 32 S Ref 1 BeBe 5662.0442 (17)5662.1143 (81)5604.8677 (17)5604.9476 (80)5551.0029 (16)N/A αeαe 32.3675 (41)32.5452 (71)31.8785 (41)32.0540 (73)31.4200 (40)N/A γeγe -0.1066 (28)N/A-0.1044 (27)N/A-0.1024 (27)N/A δeδe 0.01407 (70)N/A0.01372 (69)N/A0.01339 (67)N/A εeεe -0.002471 (59)N/A-0.002397 (57)N/A-0.002329 (55)N/A B0B0 5645.83577 (19)5645.8417 (51)5588.90427 (19)5588.9106 (50)5535.26894 (19)5535.2749 (50) B1B1 5613.28768 (19)N/A5556.84849 (19)N/A5503.67497 (19)N/A B2B2 5580.58500 (19)N/A5524.64155 (19)N/A5471.93315 (19)N/A B3B3 5547.68381 (19)N/A5492.24113 (19)N/A5440.00144 (19)N/A B4B4 5514.50311 (19)N/A5459.56855 (19)N/A5407.80525 (19)N/A B5B5 5480.87871 (19)N/A5426.46691 (19)N/A5375.19282 (19)N/A

12. 12 67 Zn 32 S This workRef. 1 B0B0 5561.64087 (50)5561.6491 (50) D0D0 0.0037339 (fixed)0.0037339 (17) 9.331 (17)N/A Natural abundance of 67 Zn 32 S is 3.9% I ( 67 Zn) = 5/2 eqQ = 13.620(8) MHz for 67 Zn metal 2 1.) Zack, L.; Ziurys, L.; J. Mol. Spec. 257 2009 213 2.) Kaufmann, E. N.; Brookeman, J.R.; Canepa, P.C.; Scott, T. A.; Rasmussen, D. H.; Perepezko, J. H. Solid State Commun. 29 1979 375

13. 13 Conclusion Our first laser ablation experiment was successful (ZnS) Metal containing species are now accessible to us 64 Zn 32 S, 66 Zn 32 S, & 68 Zn 32 S observed up to v=5, 67 Zn 32 S hyperfine splitting reported ZnS’s rotational structure has been refined and permits better prediction for ZnS-H 2 First reported closed shell 67 Zn hyperfine structure 64 Zn 34 S isotopomer (0.6%) expected to be observed but for unknown reasons was absent Dunham expansion analysis via Pickett software 1 provides insight to other Zn containing species and a method for similar analysis of other diatomics Submitted to the Journal of Molecular Spectroscopy 1.) Pickett, H.M., J. Molec. Spect. 148 1991 371

14. 14 Acknowledgements Novick/Pringle group members for insight and help on this project Professor Pickett Wesleyan machine shop for helping on setting up our laser ablation capability NSF CHE – 1011214

15. 15 Laser Entry