Cyanogen NCCN and cyanoacetylene HCCCN are isoelectronic molecules, and as such, they have many similar properties. We focus on the bond cleavage in these induced by the dissociative electron attachment. In both molecules, resonant electron attachment produces CN- with very similar energy dependence. We investigate the very different dissociation dynamics, in each of the two molecules, revealed by velocity map imaging of this common fragment. Different dynamics are manifested both in the excess energy partitioning and in the angular distributions of fragments. Based on the comparison with electron energy loss spectra, which provide information about possible parent states of the resonances (both optically allowed and forbidden excited states of the neutral target), we ascribe the observed effect to the distortion of the nuclear frame during the formation of core-excited resonance in cyanoacetylene. The proposed mechanism also explains a puzzling difference in the magnitude of the CN- cross section in the two molecules which has been so far unexplained.

Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley California 94720 United States

J Heyrovský Institute of Physical Chemistry The Czech Academy of Sciences Dolejškova 3 18223 Prague Czech Republic

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Fabrikant I. I.; Eden S.; Mason N. J.; Fedor J. Recent Progress in Dissociative Electron Attachment: From Diatomics to Biomolecules. Adv. At. Mol. Opt. Phys. 2017, 66, 545–657. 10.1016/bs.aamop.2017.02.002. DOI

Dvořák J.; Rankovič M.; Houfek K.; Nag P.; Čurík R.; Fedor J.; Čížek M. Vibronic Coupling Through the Continuum in the e + CO2 System. Phys. Rev. Lett. 2022, 129, 01340110.1103/PhysRevLett.129.013401. PubMed DOI

Ragesh Kumar T. P.; Nag P.; Rankovič M.; Kočišek J.; Mašín Z.; Fedor J.; Luxford T. F. M. Distant Symmetry Control in Electron-Induced Bond Cleavage. J. Phys. Chem. Lett. 2022, 13, 11136–11142. 10.1021/acs.jpclett.2c03096. PubMed DOI

Allan M. Study of Triplet States and Short-Lived Negative Ions by Means of Electron Impact Spectroscopy. J. Electr. Spectr. Relat. Phenomena 1989, 48, 219–351. 10.1016/0368-2048(89)80018-0. DOI

Nag P.; Polášek M.; Fedor J. Dissociative Electron Attachment in NCCN: Absolute Cross Sections and Velocity-Map Imaging. Phys. Rev. A 2019, 99, 05270510.1103/PhysRevA.99.052705. DOI

Nag P.; Nandi D. Identification of Overlapping Resonances in Dissociative Electron Attachment to Chlorine Molecules. Phys. Rev. A 2016, 93, 01270110.1103/PhysRevA.93.012701. DOI

Slaughter D. S.; Belkacem A.; McCurdy C. W.; Rescigno T. N.; Haxton D. J. Ion-Momentum Imaging of Dissociative Attachment of Electrons to Molecules. J. Phys. B 2016, 49, 22200110.1088/0953-4075/49/22/222001. DOI

Eppink A. T. J. B.; Parker D. H. Velocity Map Imaging of Ions and Electrons Using Electrostatic Lenses: Application in Photoelectron and Photofragment Ion Imaging of Molecular Oxygen. Rev. Sci. Instrum. 1997, 68, 3477–3484. 10.1063/1.1148310. DOI

Paschek K.; Semenov D. A.; Pearce B. K. D.; Lange K.; Henning T. K.; Pudritz R. E. Meteorites and the RNA World: Synthesis of Nucleobases in Carbonaceous Planetesimals and the Role of Initial Volatile Content. Astrophys. J. 2023, 942, 50.10.3847/1538-4357/aca27e. DOI

Robertson M. P.; Miller S. L. An Efficient Prebiotic Synthesis of Cytosine and Uracil. Nature 1995, 375, 772–774. 10.1038/375772a0. PubMed DOI

Millar T. J.; Walsh C.; Field T. A. Negative Ions in Space. Chem. Rev. 2017, 117, 1765–1795. 10.1021/acs.chemrev.6b00480. PubMed DOI

Agundez M.; Cernicharo J.; de Vicente P.; Marcelino N.; Roueff E.; Fuente A.; Gerin M.; Guelin M.; Albo C.; Barcia A.; Barbas L.; Bolaño R.; Colomer F.; Diez M. C.; Gallego J. D.; Gómez-González J.; López-Fernández I.; López-Fernández J. A.; López-Pérez J. A.; Malo I.; Serna J. M.; Tercero F.; et al. Probing Non-Polar Interstellar Molecules Through Their Protonated Form: Detection of Protonated Cyanogen (NCCNH+). Astron. Astrophys. 2015, 579 ((1–4)), L10.10.1051/0004-6361/201526650. PubMed DOI PMC

Agundez M.; Marcelino N.; Cernicharo J. Discovery of Interstellar Isocyanogen(CNCN): Further Evidence that Dicyanopolyynes Are Abundant in Space. Astroph. J. Lett. 2018, 861 (2), L22.10.3847/2041-8213/aad089. PubMed DOI PMC

Guelin M.; Thaddeus P. Tentative Detection of the C3N Radical. Astrophys. J. 1977, 212, L81.10.1086/182380. DOI

Thaddeus P.; Gottlieb C. A.; Gupta H.; Brunken S.; McCarthy M. C.; Agundez M.; Guelin M.; Cernicharo J. Laboratory and Astronomical Detection of the Negative Molecular Ion C3N-. Astrophys. J. 2008, 677, 1132–1139. 10.1086/528947. DOI

Agundez M.; Cernicharo J.; Guelin M.; Kahane C.; Roueff E.; Klos J.; Aoiz F. J.; Lique F.; Marcelino N.; Goicoechea J. R.; et al. Astronomical Identification of CN-, the Smallest Observed Molecular Anion. Astron. Astrophys. 2010, 517, L2.10.1051/0004-6361/201015186. DOI

Graupner K.; Merrigan T. L.; Field T. A.; Youngs T. G. A.; Marr P. C. Dissociative Electron Attachment to HCCCN. New. J. Phys. 2006, 8, 117.10.1088/1367-2630/8/7/117. DOI

Gilmore T. D.; Field T. A. Absolute Cross Sections for Dissociative Electron Attachment to HCCCN. J. Phys. B 2015, 48, 03520110.1088/0953-4075/48/3/035201. DOI

Ranković M.; Nag P.; Zawadzki M.; Ballauf L.; Žabka J.; Polášek M.; Kočišek J.; Fedor J. Electron Collisions with Cyanoacetylene HC3N: Vibrational Excitation and Dissociative Electron Attachment. Phys. Rev. A 2018, 98, 05270810.1103/PhysRevA.98.052708. DOI

Tronc M.; Azaria R. Differential Cross Section for CN- Formation From Dissociative Electron Attachment to the Cyanogen Molecule C2N2. Chem. Phys. Lett. 1982, 85, 345–349. 10.1016/0009-2614(82)80307-2. DOI

Nag P.; Polášek M.; Fedor J. Dissociative electron attachment in NCCN: Absolute Cross Sections and Velocity-Map Imaging. Phys. Rev. A 2019, 99, 05270510.1103/PhysRevA.99.052705. DOI

Luo Y.Handbook of Bond Dissociation Energies in Organic Compounds; CRC Press: 2003.

Francisco J. S.; Richardson S. L. Determination of the Heats of Formation of CCCN and HCCCN. J. Chem. Phys. 1994, 101, 7707–7711. 10.1063/1.468264. DOI

Bradforth S. E.; Kim E. H.; Arnold D. W.; Neumark D. M. Photoelectron Spectroscopy of CN-, NCO-, and NCS-. J. Chem. Phys. 1993, 98, 800–810. 10.1063/1.464244. DOI

NIST Chemistry WebBook, https://webbook.nist.gov/chemistry/.

Ervin K. M.; Gronert S.; Barlow S. E.; Gilles M. K.; Harrison A. G.; Bierbaum V. M.; DePuy C. H.; Lineberger W. C.; Ellison G. B. Bond Strengths of Ethylene and Acetylene. J. Am. Chem. Soc. 1990, 112, 5750–5759. 10.1021/ja00171a013. DOI

Harrison S.; Tennyson J. Electron Collisions with the CN Radical: Bound States and Resonances. J. Phys. B: At. Mol. Opt. Phys. 2012, 45, 03520410.1088/0953-4075/45/3/035204. DOI

Gao X.-F.; Xie J.-C.; Li H.; Meng X.; Wu Y.; Tian S. X. Direct Observation of Long-Lived Cyanide Anions in Superexcited States. Communications Chemistry 2021, 4, 13.10.1038/s42004-021-00450-0. PubMed DOI PMC

Skomorowski W.; Gulania S.; Krylov A. I. Bound and Continuum-Embedded States of Cyanopolyyne Anions. Phys. Chem. Chem. Phys. 2018, 20, 4805.10.1039/C7CP08227D. PubMed DOI

Ng L.; Balaji V.; Jordan K. D. Measurement of The Vertical Electron Affinities of Cyanogen and 2,4-Hexadiyne. Chem. Phys. Lett. 1983, 101, 171–176. 10.1016/0009-2614(83)87365-5. DOI

Nag P.; Čurík R.; Tarana M.; Polášek M.; Ehara M.; Sommerfeld T.; Fedor J. Resonant States in Cyanogen NCCN. Phys. Chem. Chem. Phys. 2020, 22, 2314110.1039/D0CP03333B. PubMed DOI

Sebastianelli F.; Carelli F.; Gianturco F. Forming (NCCN)- by Quantum Scattering: A Modeling for Titan’s Atmosphere. Chem. Phys. 2012, 398, 199–2015. 10.1016/j.chemphys.2011.08.004. DOI

Sommerfeld T.; Knecht S. Electronic Interaction Between Valence and Dipole-Bound States of the Cyanoacetylene Anion. Eur. Phys. J. D 2005, 35, 207–216. 10.1140/epjd/e2005-00078-8. DOI

Sebastianelli F.; Gianturco F. Metastable Anions of Polyynes: Dynamics of Fragmentation/Stabilization in Planetary Atmospheres After Electron Attachment. Eur. Phys. J. D 2012, 66, 41.10.1140/epjd/e2011-20619-8. DOI

Kaur J.; Mason N.; Antony B. Cross-Section Studies of Cyanoacetylene by Electron Impact. J. Phys. B 2016, 49, 22520210.1088/0953-4075/49/22/225202. DOI

Allan M.; May O.; Fedor J.; Ibǎnescu B. C.; Andric L. Absolute Angle-Differential Vibrational Excitation Cross Sections for Electron Collisions with Diacetylene. Phys. Rev. A 2011, 83, 05270110.1103/PhysRevA.83.052701. DOI

O’Malley T. F.; Taylor H. S. Angular Dependence of Scattering Products in Electron-Molecule Resonant Excitation and in Dissociative Attachment. Phys. Rev. 1968, 176, 207–221. 10.1103/PhysRev.176.207. DOI

Tronc M.; Fiquet-Fayard F.; Schermann C.; Hall R. I. Angular Distributions of O- From Dissociative Electron Attachment to N2O Between 1.9 to 2.9 eV. J. Phys. B 1977, 10, L45910.1088/0022-3700/10/12/005. DOI

Connors R. E.; Roebber J. L.; Weiss K. Vacuum Ultraviolet Spectroscopy of Cyanogen and Cyanoacetylenes. J. Chem. Phys. 1974, 60, 5011.10.1063/1.1681016. DOI

Ferradaz T.; Benilan Y.; Fray N.; Jolly A.; Schwell M.; Gazeau M. C.; Jochims H.-W. Temperature-Dependent Photoabsorption Cross-Sections of Cyanoacetylene and Diacetylene in the Mid-and Vacuum-UV: Application to Titans Atmosphere. Planet. Space. Sci. 2009, 57, 10–22. 10.1016/j.pss.2008.10.005. DOI

Ovad T.; Sapunar M.; Sršeň Š.; Slavíček P.; Mašín Z.; Jones N. C.; Hoffmann S. V.; Ranković M.; Fedor J. Excitation and Fragmentation of the Dielectric Gas C4F7N: Electrons vs Photons. J. Chem. Phys. 2023, 158, 01430310.1063/5.0130216. PubMed DOI

Duflot D.; Hoffmann S. V.; Jones N. C.; Limão-Vieira P. In Radiation in Bioanalysis: Spectroscopic Techniques and Theoretical Methods; Pereira A. S., Tavares P., Limão-Vieira P., Eds.; Springer International Publishing: Cham, 2019; pp 43–81.

Zlatar M.; Allan M.; Fedor J. Excited States of Pt(PF3)4 and Their Role in Focused Electron Beam Induced Deposition. J. Phys. Chem. C 2016, 120, 10667–10674. 10.1021/acs.jpcc.6b02660. DOI

Fischer G.; Ross I. G. Electronic Spectrum of Dicyanoacetylene. 1. Calculations of the Geometries and Vibrations of Ground and Excited States of Diacetylene, Cyanoacetylene, Cyanogen, Triacetylene, Cyanodiacetylene, and Dicyanoacetylene. J. Phys. Chem. A 2003, 107, 10631–10636. 10.1021/jp034966j. DOI

Job V. A.; King G. W. The Electronic Spectrum of Cyanoacetylene. Part I. Analysis of the 2600 A System. J. Mol. Spectrosc. 1966, 19, 155–177. 10.1016/0022-2852(66)90238-4. DOI

Luo C.; Du W. N.; Duan X. M.; Li Z. S. A Theoretical Study of the Photodissociation Mechanism of Cyanoacetylene in Its Lowest Singlet and Triplet Excited States. Astrophys. J. 2008, 687, 726–730. 10.1086/591486. DOI

Silva R.; Gichuhi W. K.; Kislov V. V.; Landera A.; Mebel A. M.; Suits A. G. UV Photodissociation of Cyanoacetylene: A Combined Ion Imaging and Theoretical Investigation. J. Phys. Chem. A 2009, 113, 11182–11186. 10.1021/jp904183a. PubMed DOI

Allan M. Measurement of Absolute Differential Cross Sections for Vibrational Excitation of O2 by Electron Impact. J. Phys. B 1995, 28, 5163.10.1088/0953-4075/28/23/021. DOI

Allan M. Measurement of the Elastic and v = 0 →1 Differential Electron-N2 Cross Sections over a Wide Angular Range. J. Phys. B 2005, 38, 3655–3672. 10.1088/0953-4075/38/20/003. DOI

Brauer G.Handbook of Preparative Inorganic Chemistry, 2nd ed.; Academic Press: New York, 1963; Vol. I, pp 658–662.

Miller F. A.; Lemmon D. H. Infrared and Raman Spectra of Dicyanodiacetylene. Spectrochim. Acta, Part A 1967, 23, 1415.10.1016/0584-8539(67)80363-5. DOI

Frisch M. J.; Trucks G. W.; Schlegel H. B.; Scuseria G. E.; Robb M. A.; Cheeseman J. R.; Scalmani G.; Barone V.; Petersson G. A.; Nakatsuji H.. et al. Gaussian Inc16̃ Revision C. Gaussian Inc.: Wallingford CT, 2016.

Dunning T. H. Gaussian Basis Sets for Use in Correlated Molecular Calculations. I. The Atoms Boron Through Neon and Hydrogen. J. Chem. Phys. 1989, 90, 1007–1023. 10.1063/1.456153. DOI