Gas Phase Formation and Photodissociation Spectroscopy of Mass Selected Nitrogen and Oxygen Substituted Carbon Clusters IM FACHBEREICH PHYSIK DER FREIE UNIVERSITÄT BERLIN EINGEREICHTE DISSERTATION ZU ERLANGUNG DER GRADES EINES DOKTORS DER NATURWISSENSCHAFTEN Von Matthieu Lalanne Berlin, July 2015 Hiermit erkläre ich, dass ich vorgelegte Dissertation selbst verfasst und mich dabei keiner anderen als der von die bezeichneten Quellen bedient habe. Weiterhin erkläre ich hiermit, dass ich an keiner anderen Stelle ein Prüfungsverfahren beantragt bzw. die Dissertation in dieser einer anderen Form bereits anderweitig als Prüfungsarbeit verwendet oder einer anderen Fakultät als Dissertation vorgelegt habe. Berlin den, . Unterschrift DISPUTATION: 10.11.2015 Erstgutachter: Prof. Drs. Ludger Wöste Zweitgutachter: Priv.-Doz. Dr. Albrecht Lindinger Contents Abbreviation ............................................................................................... x Introduction 1 1. Panspermia and exogenous theories ...................................................... 1 2. Anions and amino acids in interstellar medium ........................................ 3 3. Synthesis in quasi interstellar conditions: Carbon Sputtering........................ 4 Outline of the thesis ............................................................................ 7 1. Theoretical basis 9 1.1. Cluster formation in sputtering process ................................................... 9 1.1.1 Sputtering process ................................................................... 9 1.1.2 Clusters’ formation ............................................................... 12 1.1.3 Clusters’ growth ................................................................... 13 1.2. IR vibration spectroscopy .................................................................. 18 1.2.1 Classical approach ................................................................. 19 1.2.2 Quantum approach ................................................................ 20 1.2.3 Vibrations modes .................................................................. 23 1.2.4 Infrared photodissociation ....................................................... 24 1.3. Theoretical Calculations .................................................................... 26 1.3.1 Ab initio method .................................................................... 26 1.3.2 DFT methods ....................................................................... 27 1.3.3 Basis set .............................................................................. 28 2. Experimental setup 31 2.1. The magnetron sputter source ............................................................. 31 2.2. Mass selection and trapping ................................................................ 37 2.3. Laser system .................................................................................. 43 3. Ions production and mass spectra 45 3.1. Ions production .............................................................................. 45 3.1.1 Non-linear gas pressure dependency ......................................... 45 3.1.2 Time evolution of the charged sputter yield .................................. 46 3.2. Comparison between the sputter process with O2 and N2 ........................... 47 3.3. Mass spectra by sputtering in the presence of N2 ...................................... 49 3.3.1 Negatively charged ions .......................................................... 49 - 3.3.2 Odd/ even effect in the CxNy anions ......................................... 51 3.3.3 Anions with the oddmasses ...................................................... 54 3.4. Mass spectra by sputtering in the presence of O2 ...................................... 55 3.4.1 Negatively charged ions .......................................................... 55 3.4.2 Positively charged ions ........................................................... 58 3.5. Conclusion .................................................................................... 59 vii - 4. Dicyanocarbanions CxN2 61 - 4.1. IRPD spectra of CxN2 ...................................................................... 62 4.2. Vibrational pattern .......................................................................... 64 - 4.3. Review of the different CxN2 ............................................................. 65 - CN2 ................................................................................... 65 - C3N2 .................................................................................. 65 - C4N2 .................................................................................. 66 - C5N2 .................................................................................. 66 - C6N2 ................................................................................. 68 - C7N2 .................................................................................. 68 - C8N2 ................................................................................ 69 - C9N2 ................................................................................. 69 - C10N2 ............................................................................... 69 - C11N2 ............................................................................... 69 4.4. Conclusion ................................................................................... 70 - 5. Tetracyanocarbanions CxN4 71 - 5.1. IRPD spectra of CxN4 ....................................................................... 72 5.2. Nitrile, imine carbene/carbyne vibrations pattern .................................... 73 - 5.3. Geometries shared by the CxN4 ........................................................... 75 - 5.4. Review of the different CxN4 .............................................................. 76 - C3N4 .................................................................................. 76 - C4N4 .................................................................................. 76 - C6N4 .................................................................................. 77 - C8N4 .................................................................................. 78 - C10N4 ................................................................................. 79 5.5 Conclusion ..................................................................................... 80 - 6. Carbanions Cx 81 - 6.1. IRPD spectra of Cx .......................................................................... 82 - 6.2. Parity discrepancy in the structure of Cx ............................................... 84 6.3. Absorption band characteristics .......................................................... 85 Matrix shift .......................................................................... 87 Particular sensitivity of the IRPD method ...................................... 88 - 6.4. Identification of C11 ......................................................................... 88 6.5. Conclusion .................................................................................... 89 - - 7. Oxocarbanions CxO and CxO2 91 - 7.1. IRPD spectra of CxO ....................................................................... 92 7.2. Bands intensity ............................................................................... 95 - 7.3. IRPD spectra of CxO2 ...................................................................... 96 7.4. Conclusion .................................................................................... 97 viii 8. Masses of 75, 89 and 115 amu 96 8.1. The masss 75 ................................................................................. 99 8.2. The mass 89 .................................................................................. 102 8.2.1 IRPD spectra with N2 ........................................................... 103 8.2.2 IRPD spectra with O2 ........................................................... 106 8.3. The mass 115 ................................................................................ 108 8.4. Conclusion ................................................................................... 111 - - 9. NCO and NC3O 112 - - 9.1. IRPD spectra of NCO and NC3O ....................................................... 113 - 9.2. Cyanate CNO- and linear C3NO ....................................................... 114 CNO- .......................................................................................... 114 - C3NO ........................................................................................ 112 9.3. Dicussion fort he absorption band at 2178 cm-1 ....................................... 115 - - 9.4. Predicted hydogenized form of NCO and NC3O .................................... 117 9.5. Conclusion .................................................................................. 120 Annex: Amino acids embedded in Helium droplets 121 L-glycine ................................................................................................. 122 L-valine .................................................................................................. 124 Lvaline and L-tryptophan ............................................................................. 125 L-histidine and Ltryptophan .......................................................................... 128 Conclusion............................................................................................... 131 Summary 133 Future