PARTICLE-INDUCED DESORPTION OF BENZOHYDROXAMIC ACID DERIVATIVES ADSORBED ON A COPPER SURFACE STUDIED BY LASER IONIZATION MASS SPECTROMETRY S.Wyczawska 1, E. Vandeweert 1, R. E. Silverans 1, P. Lievens 1, O.Blajiev 2, A. Hubin 2 and H. Terryn Katholieke Universiteit Leuven, 1 - Laboratory of Solid State and Magnetism, Katholieke Universiteit Leuven, Department of Metallurgy, Electrochemistry and Materials Science Faculty of Applied Science, Vrije Universiteit Brussel LAP 2006, 10 – 15 SEP 2006

BHA benzohydroxamic acids benzohydroxamic acids Formula - C 7 H 7 NO 2 Formula - C 7 H 7 NO 2

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

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

BHA BHAp-CL-BHA p-metoxy-BHAp-nitro-BHA - H - C - O - N - Cl

Outline BHA BHA Sample preparation process Sample preparation process Apparatus and measurements techniques Apparatus and measurements techniques Mass spectra and flight time distributions Mass spectra and flight time distributions Summary Summary

Electro polishing process electric current passes through submerged workpiece electric current passes through submerged workpiece VUB - Brussels Copper 85% H 3 PO 4

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

Measurement technique Ar + ions substrate

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

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

Apparatus

Apparatus Ion beam: Ion beam: - 15 keV Ar + ions bombardment; - 15 keV Ar + ions bombardment; - Ion current - 1 µA → ion fluence = ions/cm 2 ; - Ion current - 1 µA → ion fluence = ions/cm 2 ; Laser beam: Laser beam: - Resonant enhanced multiphoton ionization of benzene ring λ= 259 nm; - Resonant enhanced multiphoton ionization of benzene ring λ= 259 nm; - Non-resonant ionization of Cu; - Non-resonant ionization of Cu; - Laser energy – 1 mJpp → photon fluence = photons/cm 2 ; - Laser energy – 1 mJpp → photon fluence = photons/cm 2 ; Detection: Time of Flight Mass Spectrometry; Detection: Time of Flight Mass Spectrometry; Base vacuum – around hPa; Base vacuum – around hPa;

Apparatus Ion Gun Manipulator with Sample Holder Detector Laser beam

Spectra Physics – MOPO-730

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

Mass spectra Cubenzene heavy masses

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

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

Mass spectra  organic molecules fragments from H 2 O 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;

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;

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

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

p-Cl-BHA/Cu - H 2 O dissolved - distribution of copper is broader and shifted to lower kinetic energies; -MeOH dissolved – the same as for pure copper;

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;

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

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)

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