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June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy The Pure Rotational Spectrum of CrS (X 5  r ): Continued Studies of the 3d Transition.

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Presentation on theme: "June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy The Pure Rotational Spectrum of CrS (X 5  r ): Continued Studies of the 3d Transition."— Presentation transcript:

1 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy The Pure Rotational Spectrum of CrS (X 5  r ): Continued Studies of the 3d Transition Metal Sulfides Robin L. Pulliam, Amanda J. Higgins, and Lucy M. Ziurys University of Arizona, Department of Chemistry, Department of Astronomy, Steward Observatory, Arizona Radio Observatory, Tucson, AZ

2 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy An Introduction Previous transition metal sulfide work – VS : Laser Spectroscopy; ScS: Molecular beam optical stark measurements – MnS, FeS, NiS: previous microwave and mm-wave studies – CoS, CuS, CrS (this talk), TiS( FC11), ZnS ( FC02) – Ziurys Lab Material Sciences – metal sulfides are to known penetrate metals and alter structures and mechanical properties of metal – Solid lubricants Astrochemistry – Chromium is considered a relatively abundant nucleus – Cr atomic lines observed around stars – CrH observed around brown dwarf stars and possibly sunspots ScSTiSVSCrSMnSFeSCoSNiSCuSZnS 2+2+33 4-4-55 6+6+55 44 3-3-22 1+1+

3 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Laser-Induced Fluorescence Spectroscopy of CrS 5832 MHz 4 MHz

4 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Submillimeter Spectroscopy Radiation Source: Phase- locked Gunn oscillators and Schottky diode multipliers (65- 850 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

5 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Molecular Synthesis Sublimed chromium metal in Broida type oven (m.p. 1907 °C ) – Chromium pieces (99.2% Alfa- Aesar) – Tungsten wire baskets – Alumina crucibles – Molybdenum post – Insulated with alumina crucible pieces and ZrO felt Hydrogen sulfide gas – Between 3-5 mtorr for best production Production unstable at times

6 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy

7 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy

8 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy

9 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Data & Analysis

10 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy J+1←JΩ Parity ν obs a ν obs -ν calc a J+1←JΩ Parity ν obs a ν obs -ν calc a 24←23e281,054.135-0.3481e343,061.9130.146 f281,054.1350.1151f342,510.697-0.178 1e283,583.7700.2402e343,774.8910.074 1f284,036.216-0.2022f343,801.7720.003 2e284,638.8430.2183e345,376.959-0.160 2f284,623.248-0.4043f345,376.9590.101 3e285,951.2320.02730←29e351193.056 b -0.531 3f285,951.2320.126f351193.056 b 0.202 25←24e292,749.0410.0730e353,420.3870.204 f292,749.041-0.2440f352,607.987-0.078 0e293,969.6880.1971e354,286.283-0.191 0f294,621.185-0.2791f354,857.4230.148 1e295,847.374-0.1182e355,625.463-0.188 1f295,375.3360.1512f355,595.8570.173 2e296,459.419-0.3433e357,252.566-0.190 2f296,477.0580.3083f357,252.5660.121 3e297,842.2900.04431←30e362,875.0920.023 3f297,842.290-0.077f362875.092 b -0.695 26←25e304,442.118-0.0440e364,325.941-0.171 f304,442.1180.0900f365,172.3440.205 0e306,385.969-0.1391e366,649.4390.100 0f305,703.3430.0591f366,058.371-0.136 1e307,163.9010.0352e367,413.4480.273 1f307,655.675-0.0012f367,445.988-0.399 2e308,312.5030.27532←31e374,554.5720.393 2f308,292.815-0.229f374,554.572-0.031 3e309,730.582-0.0730e376,921.3880.091 3f309,730.5820.0750f376,040.637-0.045 27←26e316,133.1160.0041e377,826.720-0.137 f316,133.1160.0761f378,437.8860.036 0e317,434.144-0.0042e379,263.066-0.093 0f318,148.375-0.0152f379,227.6060.137 1e319,460.8850.0283e380,993.343-0.221 1f318,949.403-0.0503f380,993.3430.214 2e320,123.254-0.13333←32e386231.616 b -0.286 2f320,145.1960.239f386231.616 b 0.449 3e321,615.8560.0830e387,751.7130.049 3f321,615.856-0.0970f388,667.540-0.030 28←27e327,822.033-0.1111e390,222.673-0.026 f327,822.0330.1891f389,591.5120.106 0e329,908.3100.0893e392,858.2360.243 0f329,161.930-0.0433f392,858.236-0.269 1e330,731.709-0.12034←33e397905.906 b 0.320 1f331,263.0120.088f397905.906 b -0.753 2e331,974.9800.1430e400,410.552-0.321 2f331,950.660-0.0210f399,459.0860.137 3e333,498.020-0.1261e401,352.3370.301 3f333,498.0200.0921f402,003.561-0.218 29←28e339,508.667-0.3862e402886.961 b -0.663 f339,508.6670.1672f402844.966 b 0.547 0e340,886.567-0.0813e404,719.397-0.252 0 f341,665.6890.174 3 f404,719.3970.347

11 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Hund’s case(a) Hamiltonian Ĥ eff = Ĥ rot + Ĥ so + Ĥ so (3) + Ĥ ss + Ĥ ss (4) + Ĥ  -doubling Parameter a,b v=0 B5913.3739(59) D0.0043684(66) H x 10 -8 0.722(243) A x 10 3 9280(1580) ADAD 27.64(41) AHAH -0.0002772(10) (o+p+q)8900(2700) (p+2q)2648(56) q-14.8(3.8) (o+p+q) D 1.72(69) (p+2q) D 0.155(29) qDqD -0.0010823(95) λ x 10 3 -4901(553) λDλD 5.10(27) λHλH 0.00014429(45) η x 10 3 4527(480) ηDηD 11.27(61) θDθD -3.25(83) rms 0.139 a In MHz; b Values in parenthesis are 3  errors and apply to last quoted digit = B (J-S) 2 – D (J-S) 4 + H (J-S) 6 + A (LS) + ½ A D {LS, (J-S) 2 } + ¼ A H {LS, (J-S) 4 } + η L z S z {S z 2 - (3S 2 -1)/5} + η D / 2 {L z S z [S z 2 -(3S 2 -1)/2], (J-S) 2 } + 2 / 3 λ (3S z 2 -S 2 ) + 1 / 3 λ D {(3S z 2 - S 2 )/ 3, (J-S) 2 } + 1 / 6 λ H {(3S z 2 -S 2 ), (J-S) 4 } + θ D / 24 {(35S z 4 - 30S 2 S z 2 + 25ZS z 4 - 6S 2 + 3S 4 ), (J-S) 2 } + ½ (o+p+q) (S + 2 +S - 2 ) – ½ (p+2q) (J + S + + J - S - ) + ½ q {(J + 2 + J - 2 ) + ¼ (o+p+q) D {(S + 2 +S - 2 ), (J-S) 2 } – ¼ (p+2q) D {(J + S + + J - S - ), (J-S) 2 } + ¼ q D { (J + 2 + J - 2 ), (J-S) 2 }

12 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Interactions between rotational and electronic motions in a molecule Ground 5  r state interacting with nearby excited 5  state Splitting of two degenerate levels that are present when Λ ≠ 0 From Λ-doubling splitting and constants – learn something about the energy separation between electronic states Brown and Merer, J. Mol. Spec., 74, 488-494 (1979) Λ-doubling Molecular Energy Levels Energy Bond distance X5rX5r 5 5

13 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Λ-doubling 10  3d 3p 4s 12  11  44 55 11 X 5  r : [core] 10  2 4  4 11  1 1  2 5  1 5   : [core] 10  2 4  4 11  1 1  2 5  0 12  1 d  d  Cr S

14 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Case of pure precession – Assumption that the molecular angular momentum L is fixed and precesses around the molecular axis Λ-doubling ≈ 950 cm -1 ≈ d  d  Brown and Merer, J. Mol. Spec., 74, 488-494 (1979)

15 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Conclusion and Future Directions Verified 5  r electronic ground state Established molecular parameters for all five spin components Estimated ~950 cm -1 energy separation between the ground 5  r electronic state and a nearby 5  excited electronic state Current focus → Titanium: – Finished TiS ( 3  r ) - FC11 – Future projects TiSH ( 4 A”) and TiOH ( 4 A”)

16 June 22-26, 2009 64 th International Symposium on Molecular Spectroscopy Acknowledgements Lucy Ziurys DeWayne Halfen Amanda Higgins Rest of Ziurys Group Emily TenenbaumMing Sun Lindsay ZackJessica Dodd Gilles AdandeJie Min Matthew BucchinoBrent Harris NSF and NASA - Funding


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