near infrared spectroscopy of h 3 + and ch 2 + takeshi oka department of chemistry and department of...
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Near Infrared Spectroscopy of H3+ and CH2
+
Takeshi Oka
Department of Chemistry and Department of Astronomy and Astrophysics
The Enrico Fermi Institute, The University of Chicago
Jennifer L. Gottfried
J. Chem. Phys. 118, 10890 (2003) 121, 11527 (2004)
28th International Symposium on Free Radicals, September 5, 2005
H3+
Jupiter
Interstellar
Galactic center
Rigorous theory
Astrophysics
Charm
M. Bawendi
Li Wei Xu
Ben McCall
Jennifer Gottfried
Barrier to Linearity
2003
0
2000
4000
6000
8000
10000
12000
14000En
ergy
(cm
-1)
23
22
23
2
20
22
21
20
24
21
25
1
1+2
1+2
1
1
1+2
1+2
1+220 2
2
24 2
6
1+ 2
1+20
1+22
1+ 2
1+ 2
Vibrational Bands
Hot bands
Overtones
Forbidden transitionsCombination
bands
2 fundamental band
1980 – Oka
0
2000
4000
6000
8000
10000
12000
14000En
ergy
(cm
-1)
23
22
23
2
20
22
21
20
24
21
25
1
1+2
1+2
1
1
1+2
1+2
1+220 2
2
24 2
6
1+ 2
1+20
1+22
1+ 2
1+ 2
Vibrational Bands
22 new transitions above the barrier to linearity
Gottfried, McCall, Oka, JCP 2003
Lindsay, McCall, JMS 2001
Near-Infrared Spectrometer
BurleighWA-1500 500 MHz
19 kHz
> 104 increase in Sensitivity
Only “impurity”: Rydberg H2
Visible H3+ spectrum
Chris Neese, Chris Morong
Predissociation Spectrum
Energy diagram showing significant energies of H3+
Pseudo-low resolution convolution of experimental data [Carrington, Kennedy, J. Chem. Phys. 81, 1 (1984)]
[Kemp, Kirk, McNab, Phil. Trans. R. Soc. Lond. A 358, 2403 (2000)]
Progress of theoryNiels Bohr, 1919 First theoretical paper
Henry Eyring, 1936 – 38 A series of five papers
Coulson, 1936 MO theory, equilateral triangle
Hirschfelder, 1938 Isosceless triangle
Conroy, Christofferson, 1964 Modern ab initio
Carney and Porter, 1976 Accurate VR prediction
Watson, 1980 Traditional VR analysis
Sutcliffe and Tennyson, 1984 Variational calculation
Meyer, Botschwina, Burton, 1988 Accurate PS
Neale, Miller, Tennyson, 1996 3 million lines
Cencek, Rychlewski, Jaquet, Kutzelnigg, 1998 ΔPS<μH
Schiffels, Alijah, Hinze, 2003 Truly first principle EVR
Strong vibration-rotation interaction
ν2 2521.3 cm-1
B0 = 43.565 cm-1
C0 = 20.605 cm-1
q = - 5.372 cm-1
Oka, Phys. Rev. Lett. 45, 531 (1980)
ν1 3178.3 cm-1
Strong Fermi interaction
No off-diagonal Coriolis interaction
Giant ℓ-doubling/resonance
ζ = - 1
New paradigm of spectral analysis
Electronic Vibration Rotation
Variational method PES 1 2 B, C, D, q…
Variational method
Tennyson, Sutcliffe, Miller Dinelli (London) Jacobi
Watson (Ottawa) r1, r2 r3
Kutzelnigg, Jaquet (Bochum)
Wolniewicz, Hinze, Alijah (Torun, Bielefeld) hyperspherical
Meyer, Botschwina, Burton (1988)
Lie, Frye (1992)
Röhse, Kutzelnigg, Jaquet, Klopper (1994)
Cencek, Rychlewski, Jaquet, Kutzelnigg (1998) ΔE < 10-6 H ~ 0.2 cm-1
Obs.
[Alijah, Hinze, Wolniewicz, Ber. Bunsenges. Phys. Chem. 99, 251 (1995)][Schiffels, Alijah, Hinze, Mol. Phys. 101, 189 (2003).][Alijah, private communication (2003).]
[Neale, Miller, Tennyson, Astrophys. J. 464, 516 (1996).][Jaquet, Prog. Theor. Chem. Phys. 13, 503 (2003).]
Agreement with experiment
purely ab initio calculation!empirical correction for
nonadiabatic effects
Expectation Values (Watson)
J=0-2, J=3-5, J=6-10, J=11-15, J=16-20
Big picture H2: W. Kołos, L. Wolniewicz 1964 – 1975
J. Mol. Spectrosc. 54, 303 (1975)
H3+:Schiffels, Alijah, Hinze, Mol. Phys. 101, 175, 189 (2003)
Non-adiabatic and QED corrections missing
([H2]2)
H5+
JCP 86, 5072 (1987)
Saporoschenko JCP 42, 2760 (1964)
72 unassigned linesLindsay, McCall, JMS 210, 60 (2001)
What’s next ?
CH5+
Interstellar Chemistry
The enigma of CH+ chemistry
CH+ + H → C+ + H2 + 0.4 eVCH+ + H2→ CH2
+ + H + 1.7 eV
CH+ emission from the Red Rectangle
Vb
end(
)/cm
-1
/degrees
A2B1~
X2A1~
2uBender and Schaefer 1971
Carter and Handy 1984Reuter and Peyerimhoff 1992Kraemer, Jensen, Bunker 1994Jensen, Brum, Kraemer, Bunker 1995Osmann, Bunker, Jensen, Kraemer 1997Bunker, Chan, Kraemer, Jensen 2001
2Πu state split by Renner – Teller effect
Rösslein, Gabrys, Jagod, Oka 1992Willitsch, Imbach, Merkt, 2002Willitsch, Merkt 2003
Isoelectronic to BH2
Herzberg, Johns, 1967
C+ CH+ CH2+ CH3
+ CH4+ CH5
+H2
-H
H2
-H
H2
-H
Chemistry of CH2+
He* + CH4 CH4+
CH3+
CH2+
Production, Penning ionization
Chemical Discrimination
CH2+
“grass”H2*
Π ← Σ (0, 8, 0) ← (0, 0, 0)
Ã(0,3,0)1 X̃K(0,0,0)0
Ka
Σ ← Π (0, 9, 0) ← (0, 1, 0)
Ã(0,4,0)0 X̃K(0,0,0)1
unassigned lines
Δ ← Π (0, 9, 0) ← (0, 1, 0)
Ã(0,3,0)2 X̃K(0,0,0)1
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