FIFTY YEARS IN ION CHEMISTRY
WITH COLLEAGUES AND FRIENDS
ZDENEK HERMAN
V.Čermák Laboratory,
J. Heyrovský Institute of Physical Chemistry,
Academy of Sciences, Prague
Gordon Research Conference “Gaseous Ions”, Galveston, Keynote Lecture,, March 5, 2009
THE FIRST TRY (July 30, 1958)
INSTITUTE OF PHYSICAL CHEMISTRY, ACADEMY OF SCIENCES, PRAGUE
(Mann et al 1940) - Talroze 1952 - Stevenson, Schissler 1955-56 – Field, Franklin, Lampe 1957
1959-60
REACTIONS OF ELECTRONICALLY EXCITED REACTANT IONS
( in N2, O2, CO, CO2, COS, CS2)
N2+*(4Σu) + N2(1Σg+) → N3+(3Σg-) + N(4S)
• very small apparent cross section
• A.E.(N3+) higher than IE(N2)
• reaction endothermic with g.s. reactants
• exothermic only with electronically
excited N2+*
Vladimír Čermák
N2+*(4Σu) –
theoretically predicted
but not yet detected
A.E. =21.7 eV
V. Čermák, Z. Herman, J. Chim. Phys., 1960
1962-63
ASSOCIATIVE AND PENNING IONIZATION
Kinetics of reactions in mixtures
with metal vapors: Hg, Li, Na, K, Cs
Ion-molecule reactions
Associative ionization
(excited neutral + A ,M)
Ar*m + Hg
→ ArHg+ + e
He*m + Li
→ HeLi+ + e
Kr*m + Cs
→ KrCs+ + e
Ar*m + C2H2 → ArC2H2+ + e
Penning ionization
R*m + ABC → R + ABC+ + e
→ R + AB+ + C + e
→ R + A+ + BC + e
• mass spectra of product ions
• deposition of energy from R*m
C3H8
ION SOURCE WITH MOLECULAR BEAMS
Penning ionization electron spectroscopy
(V. Čermák)
•precise measurements of the energy of released
electron
DYNAMICS OF ION-MOLECULE REACTIONS
YALE 1964 – 65
(Richard Wolfgang)
construction of EVA I
(crossed-beam scattering machine)
Reactive scattering of neutrals in beams (1961-64)
[S.Datz, E.H Taylor (1955)] - D.R. Herschbach et al. –
E.F. Green, J. Ross – R.B. Bernstein
DYNAMICS OF ION-MOLECULE REACTIONS
DISTINGUISHING COLLISION MECHANISMS BY SCATTERING
New Haven, Boulder 1964 - 69
DIRECT MECHANISM (STRIPPING)
INTERMEDIATE COMPLEX FORMATION
• even at quasi-thermal energies
• angular scattering
• polarization stripping
• translational energy distribution
• lifetime of complexes
C2H4+ + C2H4 → [C4H8+] → C3H5+ + CH3
B. Mahan – A. Henglein - Champion, Doverspike
REACTION MECHANISMS
THE COMPLEX MINUET
SPECTATOR STRIPPING
(to which Dudley Herschbach
wrote the tune)
1970 - 1982
DYNAMICS OF ION-MOLECULE PROCESSES
Prague, after 1969
EVA II
(with V. Pacák)
DYNAMICS OF ION-MOLECULE PROCESSES
H2+(v) + He → HeH+ + H
Experiments: V. Pacak, Z. Herman, K. Birkinshaw (Prague)
Trajectory calculations: F. Schneider, U. Havemann, L. Zülicke (Berlin)
ANGULAR
TRANSLATIONAL
VIBR
ROT
OVERALL ENERGY
F.Schneider, U. Havemann, L. Zulicke, V. Pacak, K. Birkinshaw, Z. Herman, Chem.Phys.Lett. 37 (1976) 323
DYNAMICS OF ION-MOLECULE PROCESSES
Ar+ + H2 → Ar + H2+
CHARGE TRANSFER
CH4+• + CH4 → CH5+ + CH3•
PARALLEL MECHANISMS
H+- transfer complex H-atom transfer
V. Pacák - K. Birkinshaw – A. Yencha – J. Futrell – P. Hierl – M. Henchman – B. Friedrich – J. Vančura
1983 DYNAMICS OF REACTIONS OF DICATIONS
Ar2+(3P ) + He
13CO2++ 12CO
 13CO+ (B2Σ+) + 12CO+(A2Π)
CHEMICAL REACTIONS
(A2Π) + 12CO+(B2Σ+)
CF22+ + D2 → CF2+ + D2+
13CO+
→ CF2D+ + D+
PRODUCT LUMINESCENCE
CHRISTOPH
OTTINGER
He2+ + NO → He+*(2P) + NO+(1Σ+, v)
Collaboration: B. Friedrich, J. Vančura, M.
Sadílek, Z. Dolejšek, M. Fárník, L. Mrázek, J.
Žabka, J. Roithová
1998 ION - SURFACE COLLISIONS
ENERGY PARTITIONING
o
=60 , Einc=21-22eV
P(E')
100
E'int
75
CF-SAM
0.17
0.37
50
25
E'surf
E'tr
0.46
0
0
5
75
15
20
E'surf
0.06
25
ION SURVIVAL IN SURFACE COLLISIONS
CH-SAM
0.64
0.30
50
25
10
E'int
log Sa = a – b (IE)
E'tr
+
0
0
P(E')
100
5
10
15
E'surf
E'int
75
20
HOPG
CH/C(HOPG)
CD5
+
10
C7H8
+
C3H7
10
+
C3H3
+
C2H3
+
C3H5
50
+
E'tr
10
15
20
CH/SS
E'int
75
0.32
50
0.62
E'tr
0.06
25
E'surf
+
+
CD5
C3H3
5
10
+
HOPG - Room T
+
C3H6
C2H4
+
+
CD4
+
+
CD3
C3H8
20
1
+
C2H5
+
C2H4
+
CD4
+
CD3
0.1
W - Room T
0.1
15
y = (3.9±0.5) + (-0.39±0.04).x
C3H5
+
C2H2
0
0
HOPG Room Temp
+
C3H8
+
C2H5
1
25
Sa [ % ]
100
5
C3H4
+
C3H7
0
0
+
C2H3
0.66
0.28
0.06
25
P(E')
CD5
+
+
C7H7
25
Sa [ % ]
P(E')
100
+
C2H2
25
E' [eV]
+
0.01
CD4
SURFACE COLLISIONS OF CLUSTER IONS
HOPG Heated
y = (5.4±1.1) + (-0.5±0.1).x
Be - Room T
0.01
+
Ar
+
CO2
HOPG
W
Be
INNSBRUCK (1998 - )
+
+
Ar
N2
1E-3
+
N2
1E-3
collaboration with Tilmann Märk et al.
5
10
IE [eV]
15
5
10
IE [eV]
15
COLLEAGUES
AND
FRIENDS
www.jh-inst.cas.cz, personal pages - ZH
Farewell to Mike Menzinger 1969
(Mike Menzinger, Jim Kerstetter, Jim
Richardson, John Krenos, Pete Hierl,
Rod LeRoy, Dick Wolfgang, John
Hawke, Andy Yencha,
Zdenek Herman, Al Lee, Cal Blakely)
BOULDER
JILA A.D. 1980
JILA 1980: Beards and hairs of Steve Leone’s group.
JILA 1980: Carl Lineberger holding the reins
JILA 1980: The FAIR (flowing-afterglow infra-red) people:
Barney Ellison, Mark Smith, Tim Zwier, Jim Weisshaar,
Veronica Bierbaum, Zdenek Herman
CU – Chemistry 1980:
Eldon Ferguson watching the flow-tube centers
CU – Chemistry 1980: Will Castleman
CU – Chemistry 1980: Chuck DePuy
CU – Chemistry 1980: Barney Ellison
U.S.A.
Yuan T. Lee A.D. 1998
(Berkeley and Taipei)
Dudley Herschbach (Harvard) in the center of mass
Steve Berry, Chicago
Ugo Fano, Chicago
The Research Director (Graham Cooks)
Mike Henchman, Brandeis
Jean Futrell at SASP 04
GÖTTINGEN
Peter Toennies (Göttingen) and
Giorgio Benedek (Milano)
struggling with the surface lattice
dynamics
Christoph Ottinger, Göttingen
Evgenii Nikitin (Moscow, Haifa)
Jürgen Troe (Göttingen)
INNSBRUCK
Tilmann Märk
Werner Lindinger
OKAZAKI
Tamotsu Kondow
Inosuke Koyano
Saburo Nagakura
Hiroki Nakamura
EUROPEAN NETWORKS
SRMIon Network: Paul-Marie Guyon , Orsay
MCINet: Davide Bassi and Paolo Tosi, Trento
Dieter Gerlich, Chemnitz
Odile Dutuit, Orsay
Diethard Böhme, Toronto
Helmut Schwarz, Berlin
MOLEC PEOPLE
Enzo Aquilanti,
Perugia
Franco Gian-Turco (Rome)
Victor Sidis, Orsay
The two Gentlemen of Madrid:
Gerardo Delgado-Barrio and Pablo Villarreal
GORDON RESEARCH CONFERENCE , 1964