Atomic Metal Ion Chemistry
in the Gas Phase
Diethard K. Bohme
Ion Chemistry Laboratory
Department of Chemistry
Centre for Research in Mass Spectrometry
Centre for Research in Earth & Space Science
York University, Toronto, Canada

Department of Chemistry
Memorial University
October 2, 2007


Chemical Mass Spectrometry

 Create ions (in an ion source).
Look at ions (with a mass spectrometer).
resolve m/z, (dissociate), count

 Look at ions react (in a reaction cell).
Ernest Rutherford:
“Ions are jolly little beggars, you can almost see them“


Chemical Mass Spectrometry at York, since 2000 :
 2000: Invention of ICP/DRC/MS
(S. Tanner, V. Baranov, then at MDS/SCIEX)
- Dynamic Reaction Cell (DRC) for the chemical
resolution of isobaric interferences in elemental analysis
- requires chemical data base for atomic-ion reactions.

 NSERC/NRC/MDS SCIEX/York Partnership.
 ICP/SIFT tandem mass spectrometer
 2003: Suppression of chemical noise in MS, etc.
(T. Covey, MDS SCIEX)

 NSERC/MDS SCIEX/York Partnership
 ESI/qQ/SIFT/QqQ multipole ms


OUTLINE
1. ICP/SIFT tandem mass spectrometer
(the universal atomic ion chemical mass spec)
- Periodicities in Reactivities
- The Special Case of Lanthanides
- Atomic Cations as Catalysts
- Influence of Ligation
- Chemical Resolution of Atomic Isobars in
ICP/DRC/MS: a Case Study
2. ESI/qQ/SIFT/QqQ multipole mass spectrometer
(the ultimate chemical mass spectrometer)
- Chemical Reactions of Atomic Metal Dications
- Multiply-Charged Metallated Biological Ions


1.

The Universal Atomic Ion
Chemical Mass Spectrometer



The ICP/SIFT/QqQ instrument
Argon Plasma

P la s m a
S o u rc e

T u rb o
Pum p

H e liu m
I n le t

R eagent
I n le t

B lo w e r

T r ip le Q u a d r u p o le

5500 K
P = 1 atm

D iffu s io n
Pum p

T u rb o
Pum p

T u rb o

Pum p

Aqueous solution
of the atomic salt
is injected via a
nebulizer into
the Ar plasma

__________________________________________________________________________________________________________

An Inductively-Coupled Plasma / Selected-Ion Flow Tube Mass Spectrometer Study of the Chemical
Resolution of Isobaric Interferences. G.K. Koyanagi, V.I. Baranov, S. Tanner and D.K. Bohme, J. Anal. At.
Spectr. 15, 1207-1210 (2000).


Periodic Table of Atomic Salt Solutions


Attractive Features of the ICP Ion Source
 intense: ca.1011 ions s-1 in first quad (Ar+ with
0.1% metal ions), ca. 107 ions cm-3 in flow tube
 defined: thermal population of electronic states
at ca. 5500 K which relaxes toward 295 K.
 rapid: time to change metal ions ca. 30 s
 stable: not hours but weeks
 versatile: almost universal source of atomic
ions


Reactions of atomic cations: Nb+ with N2O

103

Nb + NbO 2+

+

NbO 2 ·(N 2O)2
NbNO +·(N 2O)2

102

Ion Signal

NbO 2+·(N 2O)3
NbO 2+·N 2O

NbNO +

NbO +

101

Nb+ + N2O  NbO+ + N2
 NbN+ + NO
Further Oxidation

NbO+ + N2O  NbO2+ + N2
NbN+ + N2O  NbNO+ + N2
Clustering with N2O


NbO2+ + N2O  NbO2(N2O)+
NbO2(N2O)+ +N2O NbO2(N2O)2+
NbO2(N2O)2+ +N2O NbO2(N2O)3+

+

NbNO ·N 2O

NbNO +·(N 2O)3
NbN +

100

Primary Oxidation and Nitration

+
+
NbNO
+
N
O

NbNO(N
O)
2
2
N 2O flow/(10 17 molecules s -1)
NbNO(N2O)+ +N2ONbNO(N2O)2+
________________________________________________________________
NbNO(N2O)2+ +N2ONbNO(N2O)3+

V.V. Lavrov et al., J. Phys. Chem. A 106 (2002) 4581.

0.0

1.0

2.0

3.0

4.0


Surfing the Periodic Table
H

He

59 atomic cations

Li Be
Na M g
K

C

Al Si

Ca Sc


Rb Sr

B

Y

Ti

V

O

F

Ne

P

S

Cl Ar

Cr M n Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Z r N b M o T c R u R h P d A g C d In S n S b T e

C s B a L a H f Ta
Fr Ra Ac

N


W

Re Os

Ir

I

Xe

Pt Au Hg Tl Pb Bi Po At Rn

C e Pr N d Pm Sm Eu G d Tb D y H o Er Tm Yb Lu

Some MO+ oxide ions
15 different molecules
O2, NO, N2O, NO2, CO2, CS2, OCS, D2O,
NH3, CH4, CH3F, CH3Cl, SF6, C6H6, C6F6

1000
5000
2500


Web Data Base

61 atomic cations x 15 molecules = 915 reactions !!
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Periodicities in Reactivities


Reactions of atomic cations with O2
1.0
0.8

Reaction branching ratio / Efficiency (k/kc)

0.6
0.4

+

Ca

+

1.0

+

1

0

1 1

s


s

2 1

ds ds

0.8
0.6
0.4

+

Y

0.2
0.0
1.0

4

5

d

0

1

s


+

Zr Nb
2 1

s ds

6 1

d d s ds
(2) (2)

+

2

s

5 1

4

d

8

10

9


d

+

+

d

d
+

+

10 1

0

1

+

+

+

+

As
2


p

d s p

+

+

M+ + O2

3

p
+

Se

p
+

+

Pd Ag Cd In Sn Sb Te
Mo Tc Ru Rh Pd
+

Rb Sr

+


(2) (2) (2) (2)

+

+

+

+

+
+
+
+
+
V Cr Mn Fe Co Ni Cu Zn Ga Ge

Sc Ti

0.2
0.0

+

+

K

(2) (2)


5

d

5 1

7

ds d

8

d

9

d

10

d

10 1

0

1

d s p


p

2

p

3

p

 MO+ + O
 M+(O2)

0.8
0.6
0.4
0.2
0.0
1.0

+
+
+
+
+
+
+
+
+
+

+
Cs Ba La+ Hf+ (2)+ (2)+ Re Os+ Ir Pt Au Hg Tl Pb Bi Po
(2) (2) (2)
(2) Ta W
0

1

s

2

s

d

1 2

3 1

0.8

0.2
0.0

+

5 1

+


+

6 1

+

Ce Pr

7 1

9

+

+

Nd Pm

10

d
+

Sm Eu

0.6
0.4

4 1


d s d s d s ds d s ds d

+

+

Gd Tb

10 1

0

d s p

1

p

2

p

3

p

+

+

+
Dy Ho Er+ Tm Yb+ Lu

Os+ + 2O2
 OsO+ + O3

f1d2 f3s1 f4s1 f5s1 f6s1 f7s1 f7d1s1 f9s1 f10s1 f11s1 f12s1 f13s1 f14s1 f14s2

O-atomtransfer

O2 clustering

Not measured

2nd order O-atomtransfer

No reaction

G.K. Koyanagi et al., J. Phys. Chem. A 106 (2002) 4581.


Reactions of atomic cationswith CO2
1.0
0.8
0.6

+

+
K+ Ca Sc+ Ti


+
+
+
+
+
+
+
+
+
V+ Cr+ Mn+ Fe Co Ni Cu Zn Ga Ge As Se

(4)

0.4

Reactioin branching ratio/Efficiency (k/kc)

0.2
0.0
1.0

2 1

s1 d1s1 d s

0

s


0.4

+

Rb Sr

(2)

0.2
0.0
1.0

+

s0

s1

+

0.4

+

Y

4

s2 d2s1 d


(3)

0.0

s0

s1

9

d

(2) (2)

d10 d10s1 p0

p1

p2

p3

+

(2) (2) (2)

5

d


d5s1 d7

(2) (2)

d8
+

+
+
+
Hf Ta W+ Re Os Ir

+

(3) (2) (2)

+
+
+
+
+
+
+
+
+
+
Zr Nb+ Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te

(2)


+

Cs Ba

0.2

d5 d5s1 d6s1 d8

+

0.8
0.6

(2)

(2)

0.8
0.6

d4

(3) (2) (2)

(2) (3)

La+

d9


(2)
d10 d10s1 p0
+

+

+
Pt Au+ Hg Tl

(3) (2) (2)

6 1
4 1
d2 d1s2 d3s1 d s d5s1 d s d7s1 d9

1

p

2

p

p3

M+ + CO2
 MO+ + CO
 M+(CO2)

Pb+ Bi+ Po+

(2) (2)

d10 d10s1 p0

p1

2

p

3

p

1.0
0.8
0.6
0.4
0.2
0.0

+
+
+
+
+
+
+
+
Ce+ Pr+ Nd+ Pm+ Sm+ Eu+ Gd Tb Dy Ho Er Tm Yb Lu


(3)

(2)

f1d2 f3s1 f4s1 f5s1 f6s1 f7s1 f7d1s1 f9s1 f10s1 f11s1 f12s1 f13s1 f14s1 f14s2

O-atom transfer

CO2 clustering

Not measured

G.K. Koyanagi, D.K. Bohme, J. Phys.Chem. A 110 (2006) 1232.


Reactions of atomic cations with N2O
1.0
0.8
0.6
0.4

Reactioin branching ratio/Efficiency (k/kc)

0.2
0.0
1.0

(2) (2)


+
+
+
+
+
+
+
Se
Mn+ Fe (3) Ni Cu Zn Ga Ge
+
K Ca Sc Ti V Cr
As
Co+ (3) (2)
(2)
(2)
+

+

+

2 1

s1 d1s1 d s

0

s

+


+

d4

d5 d5s1 d6s1 d8

0.8
0.6
0.4

+
Rb+ Sr
+

s0

(2) (2)
4

s1

9

d

d10 d10s1 p0

p1


2

p

M+ + N2O

3

p

Mo+ Tc+ Ru+ Rh+ Pd+ Ag+ Cd+ In+ Sn+ Sb+ Te+
(2) (2)

Y Zr+ Nb+

0.2
0.0

(2)

+

s2 d2s1 d

5 1
d5 d s d7

(2) (2)

d8


d9 d10 d10s1 p0

p1

p2

p3

 MO+ + N2
 MN+ + NO

1.0
0.8
0.6

Cs+

+

+

+

+

+

Ba La Hf Ta W Re


0.4

Os+ Ir+ Pt+ Au+ Hg+ Tl+ Pb+ Bi+ Po+

(2) (2) (3) (2) (4)

0.2
0.0

+

0

1

s

s

2

d

(3)

(2) (2)

6 1
1 2 3 1 4 1
9

10
10 1
d s d s d s d5s1 d s d7s1 d d d s p0

p1

p2

1.0
0.8
0.6
0.4

Ce+

Pr+ Nd+ Pm+ Sm+
Eu+

 M+(N2O)

p3
(2)

Gd+

+

+

+


+

+

Tb Dy Ho Er Tm Yb
+

+

Lu

0.2
0.0

f1d2 f3s1 f4s1 f5s1 f6s1 f7s1 f7d1s1 f9s1 f10s1 f11s1 f12s1 f13s1 f14s1 f14s2

O-atom transfer

N2O clustering

Not measured

No reaction

N-atom transfer

V.V. Lavrov et al., J. Phys. Chem. A 106 (2002) 4581.



Reaction Branching Ratio/Efficiency (k/kc)

Reactions of atomic cations with SF6
1.0
0.8
0.6
0.4
0.2
0.0
1.0
0.8
0.6
0.4
0.2
0.0
1.0
0.8
0.6
0.4
0.2
0.0
1.0
0.8
0.6
0.4
0.2
0.0

(2)
+


K

0

(3) (4)
+

+ Ti
Ca+ Sc

+

V

1 1 2 1
4
s1 d s d s d

s

(2)
+

Rb

+

Sr+
0


1

s

s

Y

(3)

d9

10

d

10 1

d s

p0

1

p

2

p


3

p

+

4

2
s d2s1 d
(2) (3) (3)

5 1

d5 d s
(4)

d7

8

9

d

d

10


d

10 1

0

p1

d s p

p2

3

p

+

+
+
+
+
+
+
+
+
+
W Re Os Ir Pt Au Hg Tl Pb+ Bi Po

(2) (2)


6 1

s1

Pm Sm

+

Eu

M+ + SF6
 MFn+ + SF6-n
 M+(SF6)
 SFn+ + MF6-n

1

d2 d1s2 d3s1 d4s1 d5s1 d s d7s1 d9 d10 d10s1 p0 p p2 p3
(2) (2)
(2) (2) (2) (2) (2) (2) (2)
(2)
+
+
(2) (2)
Er Tm Yb+
+
+
+
+


Ce+ Pr+ Nd+
f1d2

5 1
d5 d s d6s1 d8

As

Se

+
+
Mo+ Tc+ Ru Rh+ Pd+ Ag Cd+ In+ Sn+ Sb+ Te+
Zr Nb+

+

(3)

(2) (2) (2)

+

+

(4)

Cs Ba+ La+ Hf+ Ta+
s0


+
+
+
+
+
+
+
Cr+ Mn Fe Co Ni Cu Zn Ga Ge+

Gd Tb+ Dy Ho+

+

Lu

n up to 4 !

f3s1 f4s1 f5s1 f6s1 f7s1 f7d1s1 f9s1 f10s1 f11s1 f12s1 f13s1 f14s1 f14s2

MFn+
+
M SF5

SF6 clustering

SFn

No reaction


Not measured

+

C. Ping and D.K. Bohme, J. Phys.Chem. A, in preparation.


OA(O) = 119 kcal mol-1

0

10

-1

k/kc

10

MO2+  M+ + O2  MO+ + O
-2

10

1st Row
2nd Row
3rd Row
Lanthanides

-3


10

-4

10

0

50

100

150

OA (M+) /kcal mol-1

200


0

10

1st Row
2nd Row
3rd Row
Lanthanides

-1


10

k/kc

M+N2O M+ + N2O  MO+ + N2
-2

10

100

OA(N2) = 40 kcal mol-1
10-1
10-2

-3

10

10-3

Lanthanides

-4

10

40


0

40

80

120

80

120

160

OA (M+) /kcal mol-1

160

200

10-4

200

240


Kinetic barrier due to electron interaction during bond
redisposition (conventional activation barrier).


10.0

H0 /(kcal mol-1)

TS

+
0.0

-10.0

+

-20.0

3

-30.0

6

-115.0

1

4.0 x 10-13 3.7 x 10-11 >6.4 x 10-10
B3LYP/sdd/6-311+G*

F Rh+


D Fe+
S Y+


Kinetic Barriers Due to Constraints in Electronic Spin
Slow and spin forbiddena
for formation of ground state MO+.

k

rHo

(cm3 s-1) (kcal mol-1)

Cr+ (X6S) + N2O  CrO+ (4-) + N2
<1.5x10-13 -46
Mn+ (7S) + N2O  MnO+ (5) + N2
<10-13
-28
Co+(3F) + N2O  CoO+ (5) + N2
<1.1x10-12 -35
Ni+(2D) + N2O  NiO+ (4-) + N2
<6.3x10-13 -33
Mo+ (6S) + N2O  MoO+ (4-) + N2 <3.4x10-13 -77
Ru+(4F) + N2O  RuO+ (6+) + N2
<3.3x10-13 -48
If overall spin is not conserved, a kinetic barrier is present because
a curve crossing is required to change the spin multiplicity so that
a



The special Case of Lanthanides


Ln•+ + XO  [Ln••+ O ]*  Ln::O+ + X
X
Two non-f valence electrons are required for the
lanthanide cation to participate in bonding with O.
This can be achieved by the promotion of a 4f electron:
4fn5d06s1 to 4fn-15d16s1.
(For La+, Ce+, and Lu+, the promotion corresponds to d2  d1s1 or s2  d1s1)

Exothermic reactions controlled by
the availability of valence electrons for bonding.
So can expect a correlation between reaction rate
and electron promotion energy PE !


Barriers to Electron Promotion
Ln+ + N2O  LnO+ + N2

10-10

20
40

10-11

60
80


10-12

4f n5d06s1  4f n-15d16s1

k/(cm3 molecules-1 s-1)

0

Promotion Energy/(kcal mol-1)

10-9

100
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

____________________________________________________
G.K. Koyanagi, D.K. Bohme. J. Phys. Chem. A 105, 8964 (2001)


Arrhenius would be interested!

kexp= kc e-PE/RT


Atomic Ions as Catalysts