June 20, rd International Symposium On Molecular Spectroscopy Microwave Spectrum And Structure Determination Of the CCP ( X 2 ) Radical Ming Sun DeWayne T. Halfen Lucy M. Ziurys Department of Chemistry Steward Observatory University of Arizona June 20, rd International Symposium On Molecular Spectroscopy Gas phase: solvent Free studies Pure rotational transitions Transient species: radicals/ reaction intermediates Structures, Bond lengths can be precisely determined Electronic Properties Fine-Hyperfine structures Astrochemistry Introduction to Modern FTMW Spectrometer June 20, rd International Symposium On Molecular Spectroscopy Top View E A B C D LNA 30 dB PIN Switch 0-50 dB TTL Pulse Sequence High Voltage Solenoid Valve 4-40 GHz Mixer Computer Coupler Pulse Driver S1S1 S3S3 S4S4 S4S4 S2S2 A/D S3S3 LPF + FTMW Spectrometer June 20, rd International Symposium On Molecular Spectroscopy Mirror sled Linear Actuator 20 mirrors (4 to 40 GHz operation) Complete computer control and tuning NI timing electronics and DAQ Modified FTMW++ (Jens Grabow) Two 8 gate valves for nozzle Radiation/magnetic shield planned 22 cryopump (14000 L/sec Ar) Cryopump Nozzle w/ Dischage setup FTMW Spectrometer June 20, rd International Symposium On Molecular Spectroscopy Phosphorus-Bearing Species CCP ( X 2 ) Mm/sub-mm work by Dr. DeWayne Halfen 12 C 12 CP & 13 C 13 CP Production technique Acetone free C 2 H 2 + P vapour Microwave work: 12 C 12 CP, 13 C 13 CP, 12 C 13 CP & 13 C 12 CP Production technique 12 C 12 CP/ 13 C 13 CP: 0.3% C 2 H 2 + PCl 3 vapour 12 C 13 CP/ 13 C 12 CP: 0.1% CH 4 + PCl 3 vapour June 20, rd International Symposium On Molecular Spectroscopy Molecular axis J I1I1 I2I2 F L S O 31 P: I=1/2 13 C: I=1/2 CCP ( 2 ) : Hunds case (a) H = H rot + H so + H -doubling + H mhf H rot = B(J L - S) 2 D(J L S) 4 + H(J L - S) 6 H mhf = aI z L z - (d/2)(S + I + e -2i + S - I - e +2i ) H -doubling = (S S - 2 )/2 - (p+2q)(J + S + + J - S - )/2 + q(J J - 2 )/2 + {(S S - 2 ), (J - S) 2 }/4 -(p D +2q D ) {(J + S + + J - S - ), (J - S) 2 }/4 + q D {(J J - 2 ), (J - S) 2 }/4 H so = A(L. S) + (A D /2) { (L.S), (J - S) 2 } + (A H /2) { (L.S), (J - S) 4 } June 20, rd International Symposium On Molecular Spectroscopy 1/2 +e -f 3/2 -e +f J -doublingSpin-Orbit coupling 3/2 +e -f 5/2 -e +f = 0.5 = 1.5 2r2r ~ A June 20, rd International Symposium On Molecular Spectroscopy June 20, rd International Symposium On Molecular Spectroscopy J -f +e J +f -e 31 P 13 C = 0.5 Energy 12 C 12 CP vs 13 C 13 CP June 20, rd International Symposium On Molecular Spectroscopy June 20, rd International Symposium On Molecular Spectroscopy CCP ( ) June 20, rd International Symposium On Molecular Spectroscopy June 20, rd International Symposium On Molecular Spectroscopy June 20, rd International Symposium On Molecular Spectroscopy Spectroscopic Constants for CCP (X 2 P r ) a Parameter CCP 13 CCPC 13 CP 13 C 13 CP B (26) (34) (34) (61) D (22) (23) (23) (34) H 9.50(59) x x b 9.4(2.1) x A b ADAD (10) b AHAH (86) x x b ALAL 4.8(2.3) x x b p+2q (96)47.676(17)49.997(17) (62) (p+2q) D (47) (11) (26) (p+2q) H 7.29(21) x x b 5.5(1.5) x q b qDqD 6.57(17) x x b h 1/2 (P) (30) (23) (24) (17) h 1/2D (P) (91)0.8030(86)0.8301(88)0.7984(59) d 1/2 (P) (16) (15) (15) (13) h 1/2 ( 13 C 1 ) (44)91.205(30) h 1/2D ( 13 C 1 ) (85)0.1225(56) d 1/2 ( 13 C 1 ) (19) (13) h 1/2 ( 13 C 2 ) (39)29.138(26) h 1/2D ( 13 C 2 ) (81) (53) d 1/2 ( 13 C 2 ) 2.705(18)2.716(12) MW rms MMW rms a.In MHz for C 1 C 2 P; errors are 3 in the last quoted decimal places. b.Held fixed; A held fixed to cm -1 from D. Clouthier. B A-doubling P-Hyperfine C 1 -HyperfineC 2 -Hyperfine MW-rms June 20, rd International Symposium On Molecular Spectroscopy Conclusion Bond Lengths of CCP were precisely determined and match the results from theoretical calculations. Magnetic Hyperfine structures provided useful information of electron density distribution in this molecule. Hyperfine transtions of four CCP isotopologues were obtained. June 20, rd International Symposium On Molecular Spectroscopy Acknowledgments Prof. Lucy Ziurys Dr. DeWayne Halfen Rest of Ziurys Group members Engineers and Technicians in ARO NSF NASA