Time-Resolved FTIR Emission Time-Resolved FTIR Emission Spectroscopy of the (vSpectroscopy of the (v11)-CH Stretch )-CH Stretch

of the Ketenyl (HCCO) Radicalof the Ketenyl (HCCO) Radical

Michael J. Wilhelm, William McNavage, and Raymond GrollerDepartment of Chemistry, University of Pennsylvania

Hai-Lung DaiDepartment of Chemistry, Temple University

6262ndnd International Symposium on Molecular International Symposium on Molecular SpectroscopySpectroscopy

[RF03] : Thursday, June 21, 2007[RF03] : Thursday, June 21, 2007

All Roads Lead to Ketenyl…

HCCH + …

NO2 + UV NO + O(3P)

HCCH + O(3P) HCCO + H

HCCO + O2 H + CO + CO2

combustioncombustion

atmosphericatmospheric

Past Spectroscopic Studies of Ketenyl:

K.G. Unfried, G.P. Glass, and R.F. Curl, Chem. Phys. Lett., 117, 33 (1991)

Vibrational SpectroscopyVibrational Spectroscopy Infrared Flask Kinetic Spectroscopy Infrared Flask Kinetic Spectroscopy (v(v22) Asymmetric CCO Stretch:) Asymmetric CCO Stretch:

Pure Rotational SpectrumPure Rotational Spectrum of HCCO with Sub-millimeter Wave Spectroscopy: of HCCO with Sub-millimeter Wave Spectroscopy:Large (Ka)-dependency Large (Ka)-dependency Renner-Teller Interaction Renner-Teller InteractionNear-Prolate Symmetric TopNear-Prolate Symmetric Top

Y. Endo and E. Hirota, J. Chem. Phys., 8, 4319 (1991)

Electronic SpectroscopyElectronic Spectroscopy of the B of the BX System of HCCO:X System of HCCO:LIF - Origin of the (B)-StateLIF - Origin of the (B)-StatePFY – (vPFY – (v66) CCH Bend) CCH BendSmall fluorescence quantum yield.. LIF not advisable!Small fluorescence quantum yield.. LIF not advisable!

Osborn, Mordaunt, Choi, Bise, Neumark and Rohlfing, J. Chem. Phys., 106, 10087 (1997)Brock, Mischler, and Rohlfing, J. Chem. Phys., 110, 6773 (1999)

%0;

%37;~

%63;~/

~

32

324

3222

3.19332

CHCHOHCC

CHCHAaHCCO

CHCHAAXHCCOCHCHOHCC nm

M.J. Krish, J.L. Miller, and L.J. Butler, M.J. Krish, J.L. Miller, and L.J. Butler, J. Chem. PhysJ. Chem. Phys., ., 119119, 176 (2003), 176 (2003)

Generation of Ketenyl..Generation of Ketenyl..

AX 2~

Collider Gas Input

[2-10 Torr]

Sample Input[10 – 100

mTorr]

Oscilloscope

Bruker Transient Recorder

BoardPad82a

MM

IFS 66sIFS 66s

Time-Resolved Fourier Transform Infrared Emission Spectroscopy (TR FTIRES):Time-Resolved Fourier Transform Infrared Emission Spectroscopy (TR FTIRES):

ArF Excimer : LPX 200{l = 193 nm, 20 Hz, ≤ 100 mJ/pulse}

Pre-Amp +

Amplifier

Win2K PC / OPUS

f1 f2

Photodiodetrigger

Gas

Cell

To Glass Manifold / Mechanical Pump(i.e. Continuous Flow..)

Capacitance Manometer[0-10 Torr]

Step-Scan

RA + h193.3 nm R‡ + A‡

R‡(v’=k) + M R‡(v’=k-1) + M*

:

R‡(v’=1) + M R (v’=0) + M*

HCC-O-CH2CH3 + (193 nm) HCCO + CH2CH3

220

200

180

160

140

120

100

80

60

40

20

0

Nor

maliz

ed E

miss

ion

Inte

nsity

/ a

.u.

3800360034003200300028002600240022002000Frequency / cm-1

Time-Resolved FTIR Emission Spectra:

AX 2~HCCO(v2) CO

HCC[XA]CH2CH3 (?) {HCC(v1) HCCO(v1)}

-- Early-- Late

2D Cross-Spectral Correlation Analysis:

AX 2~

(A)

(B)

Frequency / cm-1

Inte

nsi

ty /

a.u

.

Time / s

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Inte

nsity

/ a

.u.

10.09.08.07.06.05.04.03.02.01.00.0

Time / s

(A)

Time / Time / ss

Inte

nsi

ty /

a.u

.

FrequencyFrequency

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

-0.2

-0.4

-0.6

Inte

nsity

/ a

.u.

10.09.08.07.06.05.04.03.02.01.0

Time / s

(B)

Time / Time / ss

Inte

nsi

ty /

a.u

.

FrequencyFrequency

niSignalSignal eII 0 ki

NoiseNoise eII

212121 ,,, iX

synchronoussynchronous asynchronous asynchronous

2D Cross-Spectral Synchronous Correlation Analysis:

AX 2~

16.2 16.2 ss

Tim

e-R

eso

lved D

ata

Tim

e-R

eso

lved D

ata

Set(

1)

Set(

1)

Time-Resolved Data Time-Resolved Data Set(2)Set(2)

212121 ,,, iX

2D Cross-Spectral Synchronous Correlation Analysis:

0.05-1.75 0.05-1.75 ss((0.9 0.9 ss))

5.15-6.85 5.15-6.85 ss((6.0 6.0 ss))

AX 2~

10.25-11.95 10.25-11.95 ss((11.1 11.1 ss))

15.35-17.05 15.35-17.05 ss((16.2 16.2 ss))

Extracted (time-resolved) Synchronous Diagonals:

40

36

32

28

24

20

16

12

8

4

0

Em

issi

on I

nten

sity

/ a

.u.

3800360034003200300028002600240022002000

Frequency / cm-1

1.2

1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0E

mis

sion

Inte

nsity

/ a.

u.

360035003400330032003100300029002800

16.2 s

0.9 s

16.2 s

AX 2~

HCCO(v1)

HCCH(v3)HCC(v1)

PTS + Vibronic

MS-TOF

2D Cross-Spectral Asynchronous Correlation Analysis:

AX 2~ 212121 ,,, iX

Tim

e-R

eso

lved D

ata

Set(

1)

Time-Resolved Data Time-Resolved Data Set(2)Set(2)

2D Cross-Spectral Asynchronous Correlation Analysis:

12 33003200 cmHCCO

AX 2~

CO(01)

HCCO(v2)

1.2

1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

Em

issi

on

In

ten

sity

/ a

.u.

34003360332032803240320031603120308030403000Frequency / cm

-1

Rotational Contour Simulation:

AX 2~

1.2

1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

Em

issi

on I

nten

sity

/ a.

u.

34003360332032803240320031603120308030403000

Frequency / cm-1

8

6

4

2

0

1,,1,;,1,;, 1111 aakak KKJJKJ

HCCH (v3)

HCC (v1)

HCCO[v1] ~ 3232 cm-1

Near-Prolate Symmetric Top..Near-Prolate Symmetric Top..

IR Spectral Assignments:

AX 2~

[X1] – Gaussian03 Calculation[X1] – Gaussian03 Calculation[X2] – Peter Szalay (Private Communication)[X2] – Peter Szalay (Private Communication)

Acknowledgments:

U.S. Department of EnergyU.S. Department of Energy, , Basic Energy Sciences Basic Energy Sciences

NASA Earth System Science Fellowship (WM) NASA Earth System Science Fellowship (WM)

Financial Support:

People:

Hai-Lung Dai (Advisor)Hai-Lung Dai (Advisor)

Matt NikowMatt NikowMin ZhangMin ZhangGrazia GonellaGrazia GonellaJia ZengJia Zeng

Jianqiang MaJianqiang MaJun HanJun HanMichelle WangMichelle WangShi-Hui Jen Shi-Hui Jen

William McNavageWilliam McNavageRay GrollerRay Groller