63rd Symposium on Molecular Spectroscopy June 18, 2008

Submillimeter Spectroscopy of ZnO (X1+)

Lindsay N. Zack

Robin L. Pulliam

Lucy M. Ziurys

Departments of Chemistry and Astronomy Steward Observatory

University of Arizona

63rd Symposium on Molecular Spectroscopy June 18, 2008

Previous Work• Recent high-resolution spectroscopic studies of zinc molecules:

ZnF (Flory et al. 2006), ZnCl (Tenenbaum et al. 2007), HZnCl (WF15), HZnCN (WF16)

• All diatomic 3d transition metal oxides have been studied with high-resolution spectroscopy, except ZnO (Merer 1989)

• Most previous studies of ZnO have focused on its bulk properties- dielectric constant and bandgap energy have been determined (eg. Singh 2007)

• PES (Moravec 2001; Fancher 1998) and FTIR (matrix) (Chertihin 1996) have been used to determine the equilibrium bond lengths and vibrational frequencies

• Several theoretical studies predict re = 1.71-1.73 Å (eg. Boldyrev and Simons 1997; Bridgeman and Rothery 2000)

63rd Symposium on Molecular Spectroscopy June 18, 2008

Submillimeter Spectroscopy

• Radiation Source: Phase-locked Gunn oscillators and Schottky diode multipliers (65-660 GHz)

• Gaussian beam optics

• Reaction Chamber: Water-cooled steel cell containing a Broida-type oven

• Detector: InSb bolometer

63rd Symposium on Molecular Spectroscopy June 18, 2008

Gas-Phase Synthesis of ZnO

• Zn vapor produced in Broida-type oven

– m.p. 420 C– Zn would coat optics if not

melted slowly

• ~ 4 mTorr N2O

• d.c. discharge needed

• 12-20 mTorr Ar carrier gas

• Initial search ~ 100 GHz (~7B)

63rd Symposium on Molecular Spectroscopy June 18, 2008

64ZnO

J = 16-17

v = 0

63rd Symposium on Molecular Spectroscopy June 18, 2008

• Five Isotopologues

63rd Symposium on Molecular Spectroscopy June 18, 2008

ZnO (X1+)

J = 16 -17

63rd Symposium on Molecular Spectroscopy June 18, 2008

J = 16 - 1764ZnO

v = 066ZnO

v = 0

67ZnO

v = 0

68ZnO

v = 0

70ZnO

v = 0

5 isotopologues

64ZnO : 66ZnO : 67ZnO : 68ZnO : 70ZnO 49 : 28 : 4 : 19 : 0.6%

63rd Symposium on Molecular Spectroscopy June 18, 2008

J = 16 - 1764ZnO

v = 0

66ZnO

v = 0

67ZnO

v = 0

68ZnO

v = 0

70ZnO

v = 0

67ZnO

v = 1

68ZnO

v = 1

66ZnO

v = 164ZnO

v = 1

63rd Symposium on Molecular Spectroscopy June 18, 2008

64ZnO

v = 2

67ZnO

v = 2

64ZnO

v = 3

66ZnO

v = 268ZnO

v = 2

66ZnO

v = 368ZnO

v = 3

6nO

v = 4

Up to v = 4

J = 16 – 17

Up to v = 4

64ZnO

v = 066ZnO

v = 0

67ZnO

v = 068ZnO

v = 0

70ZnO

v = 0

67ZnO

v = 1

66ZnO

v = 2

66ZnO

v = 1

64ZnO

v = 1

63rd Symposium on Molecular Spectroscopy June 18, 2008

Transit ion 64 Zn 16 O 66 Zn 16 O 67 Zn 16 O 68 Zn 16 O 70 Zn 16 O

J ' J " v ν νobs - νc a lc ν ν

obs - νc a lc ν νobs - νc a lc ν ν

obs - νc a lc ν νobs - νc a lc

9 8 0 2 4 3 5 9 5 .8 8 4 - 0 .0 0 2 2 4 2 1 2 2 .7 7 9 - 0 .0 1 0 2 4 1 4 1 7 .3 5 2 - 0 .0 1 3 2 4 0 7 3 4 .9 7 5 - 0 .0 1 6 2 3 9 4 2 5 .4 0 4 - 0 .0 2 01 0 9 0 2 7 0 6 4 6 .4 6 4 0 .0 0 4 2 6 9 0 0 9 .8 7 8 - 0 .0 0 5 2 6 8 2 2 6 .1 5 5 - 0 .0 1 2 2 6 7 4 6 8 .0 6 1 0 .0 0 0 2 6 6 0 1 3 .1 3 0 - 0 .0 2 41 4 1 3 0 3 7 8 7 9 4 .5 2 3 0 .0 1 1 3 7 6 5 0 4 .6 4 5 0 .0 1 4 3 7 5 4 0 8 .0 7 0 0 .0 0 8 3 7 4 3 4 7 .3 3 2 0 .0 0 9 3 7 2 3 1 1 .6 6 7 0 .0 2 21 5 1 4 0 4 0 5 8 1 5 .4 9 2 0 .0 0 7 4 0 3 3 6 2 .4 8 0 0 .0 0 7 4 0 2 1 8 7 .7 9 1 0 .0 0 9 4 0 1 0 5 1 .4 8 7 0 .0 1 2 3 9 8 8 7 0 .7 9 4 0 .0 1 71 6 1 5 0 4 3 2 8 2 9 .0 5 5 0 .0 0 0 4 3 0 2 1 3 .0 1 5 0 .0 1 2 4 2 8 9 6 0 .2 4 2 0 .0 0 9 4 2 7 7 4 8 .3 9 2 - 0 .0 0 5 4 2 5 4 2 2 .7 7 2 0 .0 1 41 7 1 6 0 4 5 9 8 3 4 .7 2 8 - 0 .0 0 1 4 5 7 0 5 5 .7 1 0 - 0 .0 2 2 4 5 5 7 2 4 .9 4 0 0 .0 1 2 4 5 4 4 3 7 .6 0 3 - 0 .0 0 5 4 5 1 9 6 7 .1 2 2 0 .0 0 91 8 1 7 0 4 8 6 8 3 2 .0 0 9 - 0 .0 0 4 4 8 3 8 9 0 .1 6 9 - 0 .0 0 4 4 8 2 4 8 1 .3 7 7 - 0 .0 0 6 4 8 1 1 1 8 .6 3 8 0 .0 1 4 4 7 8 5 0 3 .3 5 5 - 0 .0 1 01 9 1 8 0 5 1 3 8 2 0 .4 0 8 - 0 .0 0 7 5 1 0 7 1 5 .8 4 3 0 .0 0 4 5 0 9 2 2 9 .1 0 0 - 0 .0 1 4 5 0 7 7 9 0 .9 5 3 - 0 .0 1 3 5 0 5 0 3 1 .0 2 0 - 0 .0 1 71 4 1 3 1 3 7 5 5 8 9 .4 8 5 - 0 .0 0 5 3 7 3 3 2 8 .6 9 3 - 0 .0 0 6 3 7 2 2 4 6 .0 2 8 0 .0 0 2 3 7 1 1 9 8 .7 0 8 - 0 .0 0 41 5 1 4 1 4 0 2 3 8 1 .4 4 7 - 0 .0 0 2 3 9 9 9 5 9 .6 1 6 0 .0 0 9 3 9 8 7 9 9 .8 0 3 - 0 .0 0 1 3 9 7 6 7 7 .8 8 8 0 .0 0 21 6 1 5 1 4 2 9 1 6 5 .9 8 9 0 .0 0 0 4 2 6 5 8 3 .1 8 6 0 .0 0 0 4 2 5 3 4 6 .2 8 0 - 0 .0 1 3 4 2 4 1 4 9 .8 1 4 0 .0 0 01 7 1 6 1 4 5 5 9 4 2 .6 2 8 0 .0 1 4 4 5 3 1 9 8 .9 4 6 0 .0 0 0 4 5 1 8 8 5 .0 1 7 0 .0 0 8 4 5 0 6 1 4 .0 1 3 0 .0 0 01 8 1 7 1 4 8 2 7 1 0 .8 2 5 - 0 .0 0 6 4 7 9 8 0 6 .3 9 2 - 0 .0 0 7 4 7 8 4 1 5 .4 8 0 0 .0 1 5 4 7 7 0 7 0 .0 0 7 0 .0 0 61 9 1 8 1 5 0 9 4 7 0 .1 4 1 - 0 .0 0 3 5 0 6 4 0 5 .0 5 9 0 .0 0 3 5 0 4 9 3 7 .1 6 6 - 0 .0 1 1 5 0 3 5 1 7 .2 8 9 - 0 .0 0 51 4 1 3 2 3 7 2 3 9 2 .2 8 7 0 .0 0 1 3 7 0 1 6 0 .5 0 0 - 0 .0 0 21 5 1 4 2 3 9 8 9 5 5 .7 9 8 0 .0 0 9 3 9 6 5 6 5 .0 1 7 - 0 .0 0 9 3 9 5 4 2 0 .0 8 5 0 .0 0 6 3 9 4 3 1 2 .4 8 9 - 0 .0 3 21 6 1 5 2 4 2 5 5 1 1 .8 3 6 - 0 .0 2 0 4 2 2 9 6 2 .2 0 3 0 .0 0 1 4 2 1 7 4 1 .1 6 2 0 .0 0 0 4 2 0 5 6 0 .0 3 8 0 .0 4 61 7 1 6 2 4 5 2 0 5 9 .9 9 1 0 .0 0 2 4 4 9 3 5 1 .5 5 8 0 .0 1 6 4 4 8 0 5 4 .4 2 8 - 0 .0 2 5 4 4 6 7 9 9 .7 1 4 0 .0 0 01 8 1 7 2 4 7 8 5 9 9 .7 1 0 0 .0 1 7 4 7 5 7 3 2 .5 5 6 0 .0 0 8 4 7 4 3 5 9 .4 9 4 0 .0 2 9 4 7 3 0 3 1 .1 8 6 - 0 .0 1 81 9 1 8 2 5 0 5 1 3 0 .4 6 5 - 0 .0 0 8 5 0 2 1 0 4 .7 4 3 - 0 .0 0 8 5 0 0 6 5 5 .7 0 3 - 0 .0 0 9 4 9 9 2 5 3 .9 8 1 0 .0 0 31 5 1 4 3 3 9 5 5 3 0 .5 9 6 - 0 .0 1 2 3 9 3 1 7 1 .1 4 0 0 .0 0 0 3 9 0 9 4 7 .9 9 8 - 0 .0 0 51 6 1 5 3 4 2 1 8 5 8 .1 5 6 0 .0 1 5 4 1 9 3 4 1 .8 8 4 0 .0 0 3 4 1 6 9 7 1 .0 1 2 0 .0 0 61 7 1 6 3 4 4 8 1 7 7 .7 0 8 0 .0 0 2 4 4 5 5 0 4 .7 5 3 0 .0 0 1 4 4 2 9 8 6 .2 2 4 - 0 .0 0 41 8 1 7 3 4 7 4 4 8 8 .7 9 8 - 0 .0 0 5 4 7 1 6 5 9 .2 5 1 - 0 .0 0 9 4 6 8 9 9 3 .1 9 0 0 .0 0 71 9 1 8 3 5 0 0 7 9 0 .9 3 5 0 .0 0 0 4 9 7 8 0 4 .9 1 8 0 .0 0 5 4 9 4 9 9 1 .3 8 2 - 0 .0 0 41 5 1 4 4 3 9 2 0 9 2 .3 6 7 - 0 .0 1 6 3 8 9 7 6 2 .6 3 1 - 0 .0 2 1 3 8 7 5 6 7 .1 2 4 - 0 .0 1 91 6 1 5 4 4 1 8 1 9 0 .7 4 1 0 .0 0 4 4 1 5 7 0 6 .2 5 5 0 .0 0 3 4 1 3 3 6 4 .9 1 0 0 .0 0 81 7 1 6 4 4 4 4 2 8 1 .1 4 4 0 .0 1 5 4 4 1 6 4 2 .0 1 6 0 .0 1 7 4 3 9 1 5 4 .9 1 8 0 .0 0 81 8 1 7 4 4 7 0 3 6 3 .0 7 3 0 .0 1 2 4 6 7 5 6 9 .4 2 6 0 .0 2 5 4 6 4 9 3 6 .7 0 6 0 .0 2 41 9 1 8 4 4 9 6 4 3 6 .0 1 9 - 0 .0 1 6 4 9 3 4 8 7 .9 4 4 - 0 .0 2 5 4 9 0 7 0 9 .7 1 1 - 0 .0 2 2

Transition Frequencies (in MHz)

116 lines were measured for 5 isotopologues over 239-514 GHz

63rd Symposium on Molecular Spectroscopy June 18, 2008

Ground State Constants (in MHz)

64ZnO 66ZnO 67ZnO 68ZnO 70ZnO

B0 13 536.4361(62) 13 454.5569(62) 13 425.3475(62) 13 377.4195(62) 13 304.6299(62)

D0 0.020563(11) 0.020314(11) 0.020196(11) 0.020082(11) 0.019861(11)

rms 0.005 0.011 0.011 0.010 0.017

For 64ZnO, B0 = 13 536 MHz and D0 = 0.0206 MHz

Very low rms!

63rd Symposium on Molecular Spectroscopy June 18, 2008

Equilibrium Parameters64ZnO 66ZnO 67ZnO 68ZnO

Be (MHz) 13 593.5679(66) 13 511.1791(66) 13 471.7303(84) 13 433.5958(66)

e (MHz) 114.3062(29) 113.2769(30) 112.8029(66) 112.3677(30)

De (MHz) 0.020539(12) 0.020296(12) 0.020172(15) 0.020070(12)

e (MHz) -0.0000494(50) -0.0000435(50) -0.000047(11) -0.0000375(50)

re (Å) 1.70826320(43) 1.70825203(43) 1.70824662(44) 1.70824142(44)

e (cm-1) 732.70(20) 730.50(20) 729.43(20) 728.39(20)

exe (cm-1) 4.8689(18) 4.8401(18) 4.8271(19) 4.8160(19)

DE, v =0 (eV) 3.3720(23) 3.3720(23) 3.3711(23) 3.3694(23)

63rd Symposium on Molecular Spectroscopy June 18, 2008

3d Transition Metal Sulfide and Oxide Bond Lengths

Oxide series now complete

ZnO (1+)

44224

??

63rd Symposium on Molecular Spectroscopy June 18, 2008

Summary and Future Work

• The predicted 1+ ground state of ZnO was confirmed

• The 3d transition metal oxide series has been completed

• Study ZnS to complete sulfide series and compare trends between oxides and sulfides

• FTMW study of 67ZnO to determine quadrupole hyperfine structure

• Astronomical search in oxygen-rich environment?

63rd Symposium on Molecular Spectroscopy June 18, 2008

Acknowledgements

• Professor Lucy Ziurys• Robin Pulliam• Dr. DeWayne Halfen• Ming Sun, Emmy Tenenbaum, Jessica Dodd, and

Gilles Adande

• Funding- NSF and NASA