Ying Guo, Xibin Gu, Fangtong Zhang, Ralf I. KaiserDepartment of Chemistry

University of Hawai’iHonolulu, HI 96822

kaiser@gold.chem.hawaii.eduhttp://www.chem.hawaii.edu/Bil301/welcome.html

Reaction Dynamics in the C(3P) + C2H2(X1g

+) System

Introduction

c-C3H(X2B2) l-C3H(X2)

Science, 274, 1508 (1996)

8.8, 28, 45 kJmol-1

Introduction

l-C3(X1g+) + H2(X1g

+) RG = - 124 kJmol-1

- 100

- 200

- 300

- 400

H

CC

C

H

-137 (-130)

-215 (-205)

-253 (-246)

-388 (-382)

HCC

C

H C C CH

H

HC C C

H

- 2 (-0.2)- 8 (-0.6)

- 124

- 42c-C3H + H

l-C3H + H

c-C3 + H2

l-C3 + H2

(Bowman et al. JCP 125 081101 (2006))

Ochsenfeld et al. JCP 106 4141 (1997)

(-128)

(-129)

C

C

C

H H

(-124)

(-12)

(-66)(-80)

(41) (31)

(-127)

C(3P) + C2H2

Mebel et al. CPL 360, 139 (2002)

rela

tive

ener

gy, k

Jmol

-1

Introduction

l-C3(X1g+) + H2(X1g

+)

Faraday Discussions 119, 27 (2001)Faraday Discussions 119, 51 (2001)

Mebel et al. JACS 120, 5751 (1998) C3 formation via ISC

- 100

- 200

- 300

- 400

H

CC

C

H

-137 (-130)

-215 (-205)

-253 (-246)

-388 (-382)

HCC

C

H C C CH

H

HC C C

H

- 2 (-0.2)- 8 (-0.6)

- 124

- 42c-C3H + H

l-C3H + H

c-C3 + H2

l-C3 + H2

(-128)

(-129)

C

C

C

H H

(-124)

(-12)

(-66)(-80)

(41) (31)

(-127)

C(3P) + C2H2

- 500H

CC

C

H

(-454)C C C

H

H

(-404)H C C C

H

(-362)

(-201)

(-64)

(-185)

(-25)(-10)

HC C C

HH

CC

C

H

ISC

Introductionre

lativ

e en

ergy

, kJm

ol-1

- 100

- 200

- 300

- 400

H

CC

C

H

-137 (-130)

-215 (-205)

-253 (-246)

-388 (-382)

HCC

C

H C C CH

H

HC C C

H

- 2 (-0.2)- 8 (-0.6)

- 124

- 42c-C3H + H

l-C3H + H

c-C3 + H2

l-C3 + H2

(-128)

(-129)

C

C

C

H H

(-124)

(-12)

(-66)(-80)

(41) (31)

(-127)

C(3P) + C2H2

- 500H

CC

C

H

(-454)C C C

H

H

(-404)H C C C

H

(-362)

(-201)

(-64)

(-185)

(-25)(-10)

HC C C

HH

CC

C

H

ISC

rela

tive

ener

gy, k

Jmol

-1

Open Questions

C2H2 9033 16.00.3 - -

C(3P)/Ne 106310 4.90.3 8.00.1 61.50.3

C(3P)/He 203725 4.90.2 20.40.4 43.80.4

C(3P)/He 258128 2.90.1 30.70.6 37.20.4

13C2H2 8905 16.00.3 - -

C(3P)/Ne 105721 5.00.3 8.00.2 63.00.6

C(3P)/He 195018 4.40.1 19.30.3 46.80.4

C(3P)/He 253739 3.30.1 30.40.9 39.30.6

C2D2 8905 16.00.3 - -

C(3P)/Ne 105912 4.90.3 8.00.1 63.00.4

C(3P)/He 197814 5.10.2 19.80.3 46.40.4

C(3P)/He 256637 3.30.1 31.00.8 39.00.6

C2HD 8905 16.00.3 - -

C(3P)/Ne 108010 5.10.3 8.10.1 61.70.4

C(3P)/He 197617 5.30.2 19.50.3 45.40.4

C(3P)/He 256645 3.20.2 30.61.0 38.00.7

beam vp, ms-1 S EC, kJmol-1 CM

3736

3938

3836

383736

m/z

- 100

- 200

- 300

- 400

H

CC

C

H

-137 (-130)

-215 (-205)

-388 (-382)

HCC

C

H

HC C C

H

- 2 (-0.2)- 8 (-0.6)

- 124

- 42c-C3H + H

l-C3H + H

c-C3 + H2

l-C3 + H2

(-128)

(-129)(-124)(-127)

C(3P) + C2H2

- 500H

CC

C

H

(-454)C C C

H

H

(-404)H C C C

H

(-362)

(-201)

(-64)

(-185)

(-25)(-10)

HC C C

HH

CC

C

H

ISC

HC C C

H

HC C C

HH

CC

C

H

ISC

TS(+150)

C C CH

H

C C CH

H

H C C CH

13

HC C C

D

- 100

- 200

- 300

- 400

H

CC

C

H

-137 (-130)

-215 (-205)

-388 (-382)

HCC

C

H

HC C C

H

- 2 (-0.2)- 8 (-0.6)

- 124

- 42c-C3H + H

l-C3H + H

c-C3 + H2

l-C3 + H2

(-128)

(-129)(-124)(-127)

C(3P) + C2H2

- 500H

CC

C

H

(-454)C C C

H

H

(-404)H C C C

H

(-362)

(-201)

(-64)

(-185)

(-25)(-10)

HC C C

HH

CC

C

H

ISC

HC C C

D

C(3P) + C2D2(X1g+)

c-C3D(X2B2) + D(2S) RG = - 2 kJmol-1

l-C3D(X2) + D(2S) RG = + 8 kJmol-1

l-C3(X1g+) + D2(X1g

+) RG = - 126 kJmol-1

c-C3(X3A2’) + D2(X1g

+) RG = - 43 kJmol-1

Ochsenfeld et al. JCP 106, 4141 (1997)Mebel et al. CPL 360, 139 (2002)

C2H2 9033 16.00.3 - -

C(3P)/Ne 106310 4.90.3 8.00.1 61.50.3

C(3P)/He 203725 4.90.2 20.40.4 43.80.4

C(3P)/He 258128 2.90.1 30.70.6 37.20.4

13C2H2 8905 16.00.3 - -

C(3P)/Ne 105721 5.00.3 8.00.2 63.00.6

C(3P)/He 195018 4.40.1 19.30.3 46.80.4

C(3P)/He 253739 3.30.1 30.40.9 39.30.6

C2D2 8905 16.00.3 - -

C(3P)/Ne 105912 4.90.3 8.00.1 63.00.4

C(3P)/He 197814 5.10.2 19.80.3 46.40.4

C(3P)/He 256637 3.30.1 31.00.8 39.00.6

C2HD 8905 16.00.3 - -

C(3P)/Ne 108010 5.10.3 8.10.1 61.70.4

C(3P)/He 197617 5.30.2 19.50.3 45.40.4

C(3P)/He 256645 3.20.2 30.61.0 38.00.7

beam vp, ms-1 S EC, kJmol-1 CM

3736

3938

3836

383736

m/z

Crossed Molecular Beams Setup

C(3P) + C2H2 (8 kJmol-1; m/z = 37)C3H

C4H

(usec)

C(3P) + C2H2 (8 kJmol-1; m/z = 36)C3H

C4H

C3(R)

C3(E)

(usec)

C(3P) + C2H2 (20.4 kJmol-1; m/z = 37)C3H

C4H

(usec)

C(3P) + C2H2 (20.4 kJmol-1; m/z = 36)C3H C4H C3H

C4H

C3(R)

C3(E)

(usec)

C(3P) + C2H2 (30.7 kJmol-1; m/z = 37)C3H

C4H

(usec)

C(3P) + C2H2 (30.7 kJmol-1; m/z = 36)C3H C4H C3H

C4H

C3(R)

C3(E)

(usec)

C(3P) + C2H2

m/z = 37 m/z = 36

C3H

C4H

C3(R)

C3(E)

C(3P) + 13C2H2

C(3P) + 13C2H2

m/z = 39 m/z = 38

C3H

C4H

C3(R)

l-C3(X1g+) + H2(X1g

+)

C(3P) + C2H2/13C2H2

C3H//13C2CHC(3P) H

13C2CC(3P) H2

C(3P) + C2H2/13C2H2

- 100

- 200

- 300

- 400

H

CC

C

H

-137 (-130)

-215 (-205)

-388 (-382)

HCC

C

H

HC C C

H

- 2 (-0.2)- 8 (-0.6)

- 124

- 42c-C3H + H

l-C3H + H

c-C3 + H2

l-C3 + H2

(-128)

(-129)(-124)(-127)

C(3P) + C2H2

- 500H

CC

C

H

(-454)C C C

H

H

(-404)H C C C

H

(-362)

(-201)

(-64)

(-185)

(-25)(-10)

HC C C

HH

CC

C

H

ISC

Summary

C2H2 9033 16.00.3 - -

C(3P)/Ne 106310 4.90.3 8.00.1 61.50.3

C(3P)/He 203725 4.90.2 20.40.4 43.80.4

C(3P)/He 258128 2.90.1 30.70.6 37.20.4

13C2H2 8905 16.00.3 - -

C(3P)/Ne 105721 5.00.3 8.00.2 63.00.6

C(3P)/He 195018 4.40.1 19.30.3 46.80.4

C(3P)/He 253739 3.30.1 30.40.9 39.30.6

C2D2 8905 16.00.3 - -

C(3P)/Ne 105912 4.90.3 8.00.1 63.00.4

C(3P)/He 197814 5.10.2 19.80.3 46.40.4

C(3P)/He 256637 3.30.1 31.00.8 39.00.6

C2HD 8905 16.00.3 - -

C(3P)/Ne 108010 5.10.3 8.10.1 61.70.4

C(3P)/He 197617 5.30.2 19.50.3 45.40.4

C(3P)/He 256645 3.20.2 30.61.0 38.00.7

beam vp, ms-1 S EC, kJmol-1 CM

3736

3938

3836

383736

m/z

Ionization Potentials of C3H Isomers

C2H2

C3H

Chemical Dynamics Beamline Advanced Light Source

L. Belau, S. Leone, M. Ahmed, R.I. Kaiser

10 20 30 40 50 60 70 80

0

5

10

15

20

2511 eV

7349

74

50

37

Ion

Inte

nsity

(cou

nts)

m/z

C3H

C4H

C4H2

C6H2

8.8 9.0 9.2 9.4 9.6 9.8 10.0

0

10

20

30 Experimental Mixture 52:48 Mixture 100:0 Mixture 0:100

Ioni

zatio

n ef

ficie

ncy

(cou

nts)

Photon energy (eV)

B. Braams J. Bowman

Ionization Potentials

IP(l-C3H) = 9.06 eV

IP(c-C3H) = 9.66 eV

0.1 eV

Experiments*

IP(l-C3H) = 9.1 eV

IP(c-C3H) = 9.6 eV

0.1 eV

*L. Belau S. Leone M. Ahmed R.I. Kaiser

Acknowledgements

Y. Guo, F. Zhang, X. Gu

L. Belau S. Leone

M. Ahmed

B. Braams J. Bowman