1 / 28

Study of Benzohydroxamic Acid Derivatives on Copper Surface by Laser Ionization Mass Spectrometry

Investigation of benzohydroxamic acid derivatives adsorbed on a copper surface using laser ionization mass spectrometry for insightful molecular analysis. The study explores sample preparation, apparatus, measurement techniques, and mass spectra analysis, shedding light on the organic molecules' behavior on the copper substrate through solvent-dependent variations. Results demonstrate the influence of solvent choice on molecule orientation, coverage, and behavior, highlighting water as the preferred solvent for organic layer formation, except for p-nitro-BHA. The study also depicts distinct velocity distribution patterns for different samples dissolved in various solvents, emphasizing the significance of solvent selection in the preparation process.

dinos
Download Presentation

Study of Benzohydroxamic Acid Derivatives on Copper Surface by Laser Ionization Mass Spectrometry

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. PARTICLE-INDUCED DESORPTION OF BENZOHYDROXAMIC ACID DERIVATIVES ADSORBED ON A COPPER SURFACE STUDIED BY LASER IONIZATION MASS SPECTROMETRY S.Wyczawska1, E. Vandeweert1, R. E. Silverans1, P. Lievens1, O.Blajiev2, A. Hubin2and H. Terryn2 1 - Laboratory of Solid State and Magnetism, Katholieke Universiteit Leuven, 2 - Department of Metallurgy, Electrochemistry and Materials Science Faculty of Applied Science, Vrije Universiteit Brussel LAP 2006, 10 – 15 SEP 2006

  2. BHA • benzohydroxamic acids • Formula - C7H7NO2

  3. BHA Hydroxamic acids and derivatives are important molecules in: • biology: antibacterial and antifungal agents, enzyme inhibitors; • medicine: anticancer agents, anemia treatments, antibiotics; • industry: pharmaceutical, corrosion inhibitors.

  4. BHA Z- amide (water, methanol) E –amide (acetone, methanol) B.Garcia, et. al, Inorganic Chemistry 2005 (44) 2908

  5. BHA - H - C BHA p-CL-BHA - O - N - Cl p-metoxy-BHA p-nitro-BHA

  6. Outline • BHA • Sample preparation process • Apparatus and measurements techniques • Massspectra and flight time distributions • Summary

  7. Electro polishing process • electric current passes through submerged workpiece Copper Copper 85% H3PO4 VUB - Brussels

  8. Spincoating • fluid resin deposited in centre of substrate • spun at high speed ± 3000 rpm. VUB - Brussels

  9. Measurement technique Ar+ ions substrate

  10. + + + + + + laser pulse Measurement technique detector Mass selection Ar+ions Δt K.E. selection substrate

  11. Measurements technique • Neutral particles sputtered from the surface are ionized by pulsed laser beam: resonance enhancement non-resonant ionization Ionization potential Excited state (intermediate) Virtual level Electronic ground state

  12. Apparatus

  13. Apparatus • Ion beam: - 15 keV Ar+ ions bombardment; - Ion current - 1 µA → ion fluence = 1011 ions/cm2; • Laser beam: - Resonant enhanced multiphoton ionization of benzene ring λ= 259 nm; - Non-resonant ionization of Cu; - Laser energy – 1 mJpp → photon fluence = 1018 photons/cm2; • Detection: Time of Flight Mass Spectrometry; • Base vacuum – around 10-9 hPa;

  14. Apparatus Laser beam Manipulator with Sample Holder Detector Ion Gun

  15. Spectra Physics – MOPO-730

  16. Our interest • new kind of organic layer; • orientation on the surface; • BHA as non toxic corrosion inhibitor (passivation); • solvents and substituents dependent;

  17. Mass spectra heavy masses Cu benzene

  18. Mass spectra • organic molecules fragments in both cases: 78, 91; • a bit less amount of organic material on MeOH dissolved samples

  19. Mass spectra • organic molecules fragments: 78, 92; • less organic signal from MeOH dissolved samples;

  20. Mass spectra • organic molecules fragments from H2O dissolved samples: 65, 78, 91, 104, 108, 118, 133 amu; • a few signal from p-methoxy-BHA/MeOH samples; • the best covered copper surface by molecules dissolved from water solution;

  21. Mass spectra • organic molecules fragments from MeOH: 78, 92, 108; • a little amount of material from water dissolved surface; • most probably more than one possible orientation on the surface;

  22. Flight time distribution T – flight time (FT) at maximum amplitude A – maximum amplitude of flight time distribution W A W – FWHM of flight time distribution T FT [µs]

  23. Copper Cu isotopes: 63 amu – 69% 65 amu – 31% • copper distribution doesn’t depend on solvent; • max. of FT – 2 µs;

  24. p-Cl-BHA/Cu • H2O dissolved - distribution of copper is broader and shifted to lower kinetic energies; • MeOH dissolved – the same as for pure copper;

  25. Maximum of FT distribution • samples dissolved in methanol show small changes in distribution; • copper from water dissolved samples is sputtered with lower kinetic energy; • p-nitro-BHA behaves different than the others samples;

  26. Summary 1. Water dissolved: Cu surface well covered by organic molecules for BHA and p-methoxy-BHA 2. Methanol dissolved:small density of molecules or only fragments of molecules on the surface

  27. Summary 3. Samples with p-nitro-BHA in MeOH show a distinct velocity distribution 4. Organic layer formation is solvent dependent: water is the best solvent for sample preparation (except for p-nitro-BHA)

  28. Thank you

More Related