PARTICLE-INDUCED DESORPTION PARTICLE-INDUCED DESORPTION OF BENZOHYDROXAMIC ACID OF BENZOHYDROXAMIC ACID DERIVATIVES ADSORBED ON A DERIVATIVES ADSORBED ON A COPPER SURFACE STUDIED BY COPPER SURFACE STUDIED BY

LASER IONIZATION MASS LASER IONIZATION MASS SPECTROMETRYSPECTROMETRY

S.WyczawskaS.Wyczawska11, E. Vandeweert, E. Vandeweert11, R. E. Silverans, R. E. Silverans11, P. Lievens, P. Lievens11, ,

O.BlajievO.Blajiev22, A. Hubin, A. Hubin22 and H. Terrynand H. Terryn22

11 - - Laboratory of Solid State and Magnetism, Katholieke Universiteit Leuven, Katholieke Universiteit Leuven,22 - - Department of Metallurgy, Electrochemistry and Materials Science Faculty of Applied Science, Vrije Universiteit Brussel LAP 2006, 10 – 15 SEP 2006

BHABHA

benzohydroxamic acidsbenzohydroxamic acids Formula - Formula - CC77HH77NONO22

BHABHA

Hydroxamic acids and derivatives aHydroxamic acids and derivatives are re important molecules in:important molecules in:

biologybiology: antibacterial and antifungal : antibacterial and antifungal agents, enzyme inhibitors;agents, enzyme inhibitors;

medicinemedicine: anticancer agents, anemia : anticancer agents, anemia treatments, antibiotics;treatments, antibiotics;

industryindustry: pharmaceutical, corrosion : pharmaceutical, corrosion inhibitorsinhibitors..

BHABHA

Z- amide (water, methanol)

E –amide (acetone, methanol)

B.Garcia, et. al, Inorganic Chemistry 2005 (44) 2908

BHABHA

BHA p-CL-BHA

p-metoxy-BHA p-nitro-BHA

- H

- C

- O

- N

- Cl

OutlineOutline

BHABHA Sample preparation processSample preparation process Apparatus and measurements Apparatus and measurements

techniquestechniques MassMass spectra and flight time spectra and flight time

distributionsdistributions Summary Summary

Electro polishing Electro polishing processprocess

electric electric current passes current passes through through submerged submerged workpieceworkpiece

VUB - Brussels

CopperCopper

85% H3PO4

SpincoatingSpincoating

fluid resin fluid resin deposited in deposited in centre of centre of substratesubstrate

spun at high spun at high speed ± 3000 speed ± 3000 rpm.rpm.

VUB - Brussels

Measurement Measurement techniquetechnique

Ar+ ions

substrate

Measurement Measurement techniquetechnique

laser pulse

++

+

+

+ +

substrate

Ar+ ions

detector

Δt

K.E. selection

Mass selection

Measurements Measurements techniquetechnique

Neutral particles sputtered from the Neutral particles sputtered from the surface are ionized by pulsed laser surface are ionized by pulsed laser beam:beam:

resonance enhancementresonance enhancement

non-resonant ionizationnon-resonant ionization

Virtual level

Electronic ground state

Excited state (intermediate)

Ionization potential

ApparatusApparatus

ApparatusApparatus

Ion beam:Ion beam: - 15 keV Ar- 15 keV Ar++ ions bombardment ions bombardment;; - Ion current - 1 µA → ion fluence = 10- Ion current - 1 µA → ion fluence = 1011 11 ions/cmions/cm22;; Laser beam:Laser beam: - Resonant enhanced multiphoton ionization of benzene - Resonant enhanced multiphoton ionization of benzene

ring ring λ= 259 nm;λ= 259 nm; - Non-resonant ionization of Cu;- Non-resonant ionization of Cu; - Laser energy – 1 mJpp → - Laser energy – 1 mJpp → photon fluence = photon fluence = 101018 18

photons/cmphotons/cm22;; Detection: Time of Flight Mass Spectrometry; Detection: Time of Flight Mass Spectrometry; Base vacuum – around 10Base vacuum – around 10-9 -9 hPa;hPa;

ApparatusApparatus

Ion Gun

Manipulator with Sample Holder

Detector

Laser beam

Spectra Physics – MOPO-730

Our interestOur interest

new kind of organic layer;new kind of organic layer; orientation on the surface;orientation on the surface; BHA as non toxic corrosion BHA as non toxic corrosion

inhibitor (passivation);inhibitor (passivation); solvents and substituents solvents and substituents

dependent;dependent;

Mass spectraMass spectra

20 40 60 80 100 120 140

-0.042

-0.040

-0.038

-0.036

-0.034

-0.032

-0.030

-0.028

-0.026

14

24

27

2830

37

39

40

5052

56

63

6578

91 103

108

118124

133

218 241

263

average of all measurements for p-methoxy BHA/water

sign

al [

arb.

u.]

mass [amu]

Cubenzeneheavy masses

Mass spectraMass spectra

20 40 60 80 100 120 140

-0.011

-0.010

-0.009

-0.008

-0.007

-0.006

14

2730

37

39

5052

56

63

78

9194130

65

sign

al [

arb.

u.]

mass [amu]

BHA/waterfull average

20 40 60 80 100 120 140

-0.022

-0.021

-0.020

-0.019

-0.018

2427

2829 37

38

40

51

53

56

63

6578

92

sign

al [

arb.

u.]

mass [amu]

BHA/methanolFull average

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

N

O

OH

H

Mass spectraMass spectra

20 40 60 80 100 120 140

-0.013

-0.012

-0.011

-0.010

-0.009

-0.008

2831

34

36

3840

51

52

56

63

65

6878

798192

98

sign

al [

arb.

u.]

mass [amu]

p-Cl-BHA/waterfull average

20 40 60 80 100 120 140-0.008

-0.007

-0.006

-0.005

-0.004

13

252627

36

38

40 50

52

56

59

63

6571

79

93104

115

sign

al [

arb.

u.]

mass [amu]

p-Cl-BHA/methanolfull average

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

N

O

OH

ClH

Mass spectraMass spectra

20 40 60 80 100 120 140

-0.042

-0.040

-0.038

-0.036

-0.034

-0.032

-0.030

-0.028

-0.026

14

24

27

2830

37

39

40

5052

56

63

6578

91 103

108

118124

133

218 241

263

average of all measurements for p-methoxy BHA/water

sign

al [

arb.

u.]

mass [amu]

20 40 60 80 100 120 140

-0.020

-0.019

-0.018

-0.017

-0.016

15

27

29

30

37

40

42

52

56

63

6578

83 9297105 120

130133

sign

al [

arb.

u.]

mass [amu]

p-methoxy_BHA/methanolfull average

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;

CN

O

OH

OH3C H

Mass spectraMass spectra

20 40 60 80 100 120 140

-0.019

-0.018

-0.017

-0.016

-0.015

13

25

27

29

38

41 51

52

56

63

6580

9194110

123

sig

na

l [a

rb.u

.]

mass [amu]

p-nitro_BHA/waterfull average

20 40 60 80 100 120 140

-0.042

-0.041

-0.040

-0.039

-0.038

-0.037

-0.036

14

26

27

37

39

4150

52

56

63

65

70

78

91108

116 128134

sign

al [

arb.

u.]

mass [amu]

p-nitro-BHA/methanolfull average

N

O

OH

NO2H

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 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

CopperCopper

0 2 4 6 8 100.00

0.01

0.02

0.03

0.04

0.05

0.06

Cu/H2O

ion

sign

al [a

rb. u

.]

flight time [µs]

Cu63 Cu65

0 2 4 6 8 100.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

Cu/MeOH

flight time [µs]

Cu63 Cu65

Cu isotopes:63 amu – 69%65 amu – 31%

- copper distribution doesn’t depend on solvent;- max. of FT – 2 µs;

p-Cl-BHAp-Cl-BHA//CuCu

0 5 10 15 20 25 30

0.002

0.004

0.006

0.008

0.010

0.012

p-Cl-BHA/H2O

ion

sig

na

l [a

rb.

u.]

flight time [µs]

63 65

0 5 10 15 20 25 30

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

0.018

p-Cl-BHA/MeOH

ion

sign

al [

arb.

u.]

flight time [µs]

63 65

- H2O dissolved - distribution of copper is broader and shifted to lower kinetic energies;-MeOH dissolved – the same as for pure copper;

Maximum of FT Maximum of FT distributiondistribution

Cu BHA Cl-BHA methoxy-BHAnitro-BHA

2

4

6

8

10

Cu 63

time

of d

elay

[µs]

sample

water methanol

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;

SummarySummary

1. Water dissolved: 1. Water dissolved:

Cu surface well covered by organic Cu surface well covered by organic molecules for BHA and p-methoxy-molecules for BHA and p-methoxy-BHA BHA

2. Methanol dissolved:2. Methanol dissolved:small density of molecules or only small density of molecules or only fragments of molecules on the fragments of molecules on the surfacesurface

SummarySummary

3. Samples with p-nitro-BHA in MeOH 3. Samples with p-nitro-BHA in MeOH show a distinct velocity distribution show a distinct velocity distribution

4. Organic layer formation is solvent 4. Organic layer formation is solvent dependent: dependent: water is the best solvent for sample water is the best solvent for sample preparation (except for p-nitro-BHA)preparation (except for p-nitro-BHA)

Thank youThank you