24
Near Infrared Spectroscopy of H 3 + and CH 2 + 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) 28 th International Symposium on Free Radicals, September 5, 2

Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

  • View
    234

  • Download
    0

Embed Size (px)

Citation preview

Page 1: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

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

Page 2: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

H3+

Jupiter

Interstellar

Galactic center

Rigorous theory

Astrophysics

Charm

M. Bawendi

Li Wei Xu

Ben McCall

Jennifer Gottfried

Page 3: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

Barrier to Linearity

2003

Page 4: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

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

Page 5: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

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

Page 6: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

Near-Infrared Spectrometer

BurleighWA-1500 500 MHz

19 kHz

Page 7: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

> 104 increase in Sensitivity

Page 8: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

Only “impurity”: Rydberg H2

Page 9: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

Visible H3+ spectrum

Chris Neese, Chris Morong

Page 10: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

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)]

Page 11: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

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

Page 12: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

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

Page 13: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

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.

Page 14: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

[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

Page 15: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

Expectation Values (Watson)

J=0-2, J=3-5, J=6-10, J=11-15, J=16-20

Page 16: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

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+

Page 17: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

Interstellar Chemistry

Page 18: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

The enigma of CH+ chemistry

CH+ + H → C+ + H2 + 0.4 eVCH+ + H2→ CH2

+ + H + 1.7 eV

CH+ emission from the Red Rectangle

Page 19: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

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

Page 20: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

C+ CH+ CH2+ CH3

+ CH4+ CH5

+H2

-H

H2

-H

H2

-H

Chemistry of CH2+

He* + CH4 CH4+

CH3+

CH2+

Production, Penning ionization

Page 21: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

Chemical Discrimination

CH2+

“grass”H2*

Page 22: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

Π ← Σ (0, 8, 0) ← (0, 0, 0)

Ã(0,3,0)1 X̃K(0,0,0)0

Ka

Page 23: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

Σ ← Π (0, 9, 0) ← (0, 1, 0)

Ã(0,4,0)0 X̃K(0,0,0)1

Page 24: Near Infrared Spectroscopy of H 3 + and CH 2 + Takeshi Oka Department of Chemistry and Department of Astronomy and Astrophysics The Enrico Fermi Institute,

unassigned lines

Δ ← Π (0, 9, 0) ← (0, 1, 0)

Ã(0,3,0)2 X̃K(0,0,0)1