1. Laboratory and Astronomical Detection of CCCN ¯ P. Thaddeus, C. A. Gottlieb, H. Gupta, S. Bruenken, M. C. McCarthy, M. Agundez, M. Guelin, and J.Cernicharo, Astrophysical Journal 677, 1132 (2008)

2. Background CCCN radical (X 2 Σ) Isoelectronic with CCCCH First observed in space (Guelin and Thaddeus1977) Glow discharge (Gottlieb et al. 1983) Supersonic beam (McCarthy et al. 1995) LIF spectrum (358 nm; Hoshina and Endo, JCP 2007) CCCN¯ in space Herbst (Nature 1981) Petrie and Herbst (ApJ 1997) Anions in the laboratory 6 anions now detected Anions in space 4 anions detected with surprisingly high abundances Conclusions

3. Spectroscopic Properties of CCCN ¯ CCCN¯ Binding energy one of highest (4.58 eV) Closed shell 1 Σ No high-resolution spectroscopy Dipole moment (3.1 D) Spectroscopic enhancement ~2.4 High-level quantum calculations Gupta and Stanton (2007) Kolos, Gronowski, and Botschwina (JCP 2008)

4. Spectral Compression

5. Laboratory Measurements Experiment: Results: Glow discharge (~20 mA) 12 transitions observed HCCCN (Ar or N 2 ) 97 - 378 GHz Concentration: 2 constants: B and D CCCN - /CCCN ~1% Mole fraction: rms = 19 kHz ~5 x 10 -8 (3 - 10) x 10 -6 HCCCN Other sources: HCCH/N 2

6. Evidence for CCCN ¯ CCCN¯ A.Experiment Closed shell ground state B within 2% of CCCN Ion drift B.Spectroscopic Measured vs theoretical: B and D eQq (McCarthy and Thaddeus FC04; JCP 2008) Ruled out: isotopic CCCN vibrationally excited CCCN CCCN+

7. radiation Ion Drift Measurements - - - - - -HV - - - - - +HV Single pass absorption with alternating polarity

8. Spectroscopic Constants _______________________________________________________ Theoretical ______________________ Constant Measured This work KGB _______________________________________________________ B 4851.62183(20) 4848 4850 10 6 xD 685.92(10) 627 628 eQq -3.248(5) -3.3 … _______________________________________________________

9. Evidence for CCCN ¯ CCCN¯ A.Experiment Closed shell ground state B within 2% of CCCN Ion drift B.Spectroscopic Measured vs theoretical: B and D eQq (McCarthy and Thaddeus FC04; JCP 2008) Ruled out: isotopic CCCN vibrationally excited CCCN CCCN +

10. Formation in Glow Discharge I. Dissociative electron attachment: A. CN¯ e¯ + NCCN  CN¯ + CN (Tronc and Azria, CPL, 1982) (Kuhn, Fenzlaff, and Illenberger, CPL, 1987) B. C 2n H¯ e¯ + HC 2n H  C 2n H¯ + H [May et al., Phys. Rev. A 77, 040701 (2008)] C. CCCN ¯ e¯ + HCCCN  CCCN ¯ + H (Graupner et al., New J. Phys., 2006) II. Other mechanisms?

11. CCCN ¯ in Space IRC+10216 4 lines observed: 97, 106, 135, and 145 GHz rms = 0.4 MHz Intensities No missing lines Spectroscopic constants Constant (MHz)LaboratoryAstronomical B4851.62183(20)4851.61(3) 10 6 x D 685.92(10) 700(100)

13. Abundances in Space TMC-1 IRC+10216 Anion/Radical # obs. calc. obs. calc. CCCN ¯ <0.8 a 1 b 0.52 a C 4 H ¯ <0.014 c 0.2 d 0.024 e 0.8 d C 6 H ¯ 1.6 c 8.9 d 8.6 f 30 d C 8 H ¯ 5 c 5.4 d 28/37 g 28 d # All ratios in % a This work; b Petrie and Herbst, ApJ 1997; c Bruenken et al. 2007; d Millar et al. ApJL 2007; e Cernicharo et al. ApJL 2007; f Kasai et al. ApJL 2007; g Remijan et al., ApJL 2007; Kawaguchi et al., PASJ 2007.

15. Properties of anions closed-shell 1 S ground states and large dipole moments (m) large electron affinities (EA) radicals are observed in astronomical sources anions do not react with H 2 Barckholtz et al., ApJL 2001 EA (eV)m (D)m (D)B (MHz) CCH 2 S 2.970.8 CCH¯ 1 S 3.141,639 C 4 H 2 S 3.560.9 C 4 H¯ 1 S 6.1 4,656 C 6 H 2 P 3.815.6 C 6 H¯ 1 S 8.2 1,377 C 8 H 2 P 3.976.3 C 8 H¯ 1 S11.9 583 CN 2 S 3.8 1.5 CN¯ 1 S 0.7 56,133 C 3 N 2 S 4.59 2.9 C 3 N¯ 1 S 3.1 4,852

16. mm-wave absorption spectrometer InSb detector LN 2 solenoid 2 m power supply Gunn × n low current dc glow discharge [C 2 H 2 (85 %) + Ar (15 %)] frequency coverage: 70 – 900 GHz frequency accuracy: 10 – 50 kHz cell walls cooled: 100-300 K